In this article, I will explain the differential equations of fluid motion, i.e., conservation of mass (the continuity equation. So without wasting any time, let us start.
As a part of this article, it is essential to know what differential analysis is and how we can apply it to explain continuity and Naiver Stroke’s theorem.
Some of the essential key points related to the differential analysis are as follows:
Differential analysis is the application of a differential equation of fluid motion to any or every point in the flow field over a region called the Flow Domain.
Some readers might confuse the word differential with the small control volumes piled up on each other in the flow field.
Whenever the size of the control volume crosses the limit and extends to infinity, then the size of each control volume becomes so small that the conservation equations simplify to a set of partial differential equations. These partial equations can easily be applicable whenever required in any flow field.
As I have discussed earlier, two differential equations, the Law of Conservation of Mass (Continuity Equation) and Newton’s Second Law (Naiver Strokes Equation), are the ones on which there is a drastic change in the temperature and density such kind of equations are easily solved with the help of differential equation.
The following diagram shows the study of control volume in which the control volume seems to be much similar to the black box.
Now, the second diagram shows that all the flow points are solved within the flow domain in the case of differential analysis.
While solving the differential equation in the case of incompressible flow, there are about four unknown, i.e., velocity components (u, v, w), one pressure component, and four equations (three equations from Naiver Strokes Law and one from Law of Conservation of Mass).
There are variables and constants in equations, but in differential equations, all the variables are solved at once because, in such situations, the equations are coupled. Now, what is coupled, and how are equations coupled? We will see it in the upcoming topics.
While solving the differential equation, the boundary conditions must be defined.
We are moving towards the first important part of our article, i.e., the Law of Conservation of Mass. Let us start.
In one of my previous articles, I have extensively explained the conservation of mass. But now, here, I will explain the derivation in terms of the infinitesimal control volume by the divergence theorem. So let’s start.
To explain the topic, I will divide it into essential critical points in the following way.
First of all, let us recall the conservation of the mass equation through the application of Reynold’s Transport Theorem;
0=∫CV∂ρ∂t dV+∫CSV.n dA (a)
The equation is for the fixed and control volumes.
In the case of well-defined and selected inlets and outlets, the equation will be as follows:
∫CV∂ρ∂tdV=inm-outn (b)
The above equation explains that the rate of change of mass within the control volume equals the rate at which mass flows into the control volume subtracting the rate with mass flow out of the control volume.
Now I will explain the derivation using the divergence theorem.
Derivation Using the Divergence Theorem:
The other name of the divergence theorem is called Gauss’s Theorem.
The statement of the divergence theorem is as follows:
The Divergence Theorem (Gauss’s Theorem) is used to transform a volume integral of the divergence of a vector into an area integral over the surface that defines the volume.
Some of the essential key points related to the Divergence theorem are as follows:
Mathematically, the divergence theorem is defined as the divergence G and can be written as follows:
∫vV.GdV=∮AG.n dA (c)
There are two kinds of integration in the equation one is simple, and the other has circled it. This indicates that the entire area surrounds the volume. So as you can see that the equation is beneficial in gaining data.
The primary purpose of using the divergence theorem is to transform the volume integral of the divergence vector into an area integral over the surface, and that surface defines the volume.
In the case of any vector, the divergence will be defined as a G, and the equation as m will be used to describe it.
In some cases, we also define the divergence as follows:
G=ρV
We can also define it by playing with the values, and for that, we substitute the value of equation (c) into equation (a), and we will get the results as follows:
0=∫cv∂ρ∂t dV+∫cvV. (ρV) dV
As you can see that there are two integrals, so to get the required equation, we will combine the two integrals into one and then the result will be as follows:
∫cv∂ρ∂t+V. VdV=0
Now, we come to the conclusion that the equation that is mentioned above is for the control volumes, regardless of any size and shape.
So, the statement above is only possible if the terms within the brackets are identically zero.
Moving towards the critical statement, i.e. the equation of continuity. So the general differential equation for the conservation of mass is also known as the continuity equation, and the equation is as follows:
∂ρ∂t+V. V=0
So, this is the equation of continuity. This equation is for compressible flows only and does not implement for incompressible ones; the -mentioned equation ensures the validity of the flow domain point.
Now that is all from the derivation using the divergence theorem. The next topic is also a part of it. Have a look.
The continuity theorem is defined in different ways, and one of them will describe by me. The continuity theorem starts with the control volume, and, taking it as a base, I will tell the whole topic.
So following are some essential key points related to the topic:
We will start with the assumption. Let us consider an infinitesimal box that controls volume and aligns with the axes in the Cartesian Coordinates system.
The following is the diagram that shows the box-shaped control volume.
As you can see from the diagram along the x-direction, the length is mentioned as dx, in the y-direction as dy and along the z-direction as the dz, respectively.
Moreover, at the centre of the box, there is information that says that the density is defined as a symbol and the velocity is defined in velocity components as u, v, and w, respectively.
So, we use Taylor's Theorem within the box at different locations away from the centre. And to define this point, we will use an example as follows:
(u)centre of right face=ρu+∂(ρu)∂xdx2+12!2(ρu)x2(dx2)2
In the case of the above-mentioned equation, the control volume has just limited to a point only, and the higher power or even the second power terms are negligible.
So, for the six faces of the box, we use the Taylor series expansion to density times the normal velocity component at the central point of each of the six faces, so they are as follows:
Center of Right Face
(u)centre of right face≅ ρu+∂(ρu)∂xdx2
Centre of left face
(u)centre of left face≅ ρu-∂(ρu)∂xdx2
Centre of Front Face
(w)centre of front face≅ ρw+∂(ρw)∂zdz2
Center of Rear Face
(w)centre of rear face≅ ρw-∂(ρw)∂zdz2
Center of Top face
(v)centre of top face≅ ρv+∂(ρv)∂ydy2
Center of Bottom face
(v)centre of bottom face≅ ρv-∂(ρv)∂ydy2
Now, there is another statement that says that
The mass flow rate into or out of the faces of the box is equal to the density times the normal velocity components at the centre point of the face times the surface area of the face.
We can define it as mathematically as follows:
m=VnA
The above equation is valid for each face. The Vn shows the magnitude of the normal velocity through the face, and the A shows the surface areas of the face.
The following diagram shows the mass flow rate through each face of our infinitesimal control volume; you will easily get the idea about it:
So all the theoretical background that I have mentioned in the diagram that is above can be easily understandable by the diagram.
For all the nonnormal velocity components, the truncated Taylor series expansions at the centre of each face can also be defined. But we have not represented as these components are tangential to the face.
Now we will move towards another equation, and that equation says the control volume shrinks at any of a point, and the value of the volume integral on the left side of the equation (b) will become as follows:
∫cv∂ρ∂t dV≅∂ρ∂tdxdydz
As we know that the volume of the box is dx, dy, and dz, respectively.
Here is a trick: with the help of the diagram, we can apply the approximations from the figure to the right side of the equation mentioned above. In this case, we will add all the mass flow rates at the inlet and the outlet of the control volume through all of the faces. Then take a left, bottom, and back faces contributing to the mass flow rate. Then concerning the equation, the right side will be as follows:
inm≅(ρu-ρu∂xdx2)dydz+ρv-ρv∂ydy2dxdz+(ρw-ρw∂zdz2)dxdy
The following are the faces that are mentioned in the equation:
Left Face =ρu-ρu∂xdx2dydz
Bottom Face=ρv-ρv∂ydy2
Rear Face=(ρw-ρw∂zdz2)dxdy
The next topic is also part of the Continuity Equation. So without wasting any time, let us start.
There is also an alternative way to present the continuity equation as we know that the following equation is according to the product rule of divergence theorem:
∂ρ∂t+V. V=∂ρ∂t+V. ρ+ρ.V=0
In order to explain the continuity equation alternative way, I will explain it in a few important key points:
The following is the alternative form of presenting the continuity equation:
1DρDt+.V=0
The above-mentioned equations show the fluid element that is flowing through the flow field, and it is also called the material element. Here there is a change that the .V is the change in the density.
So we can say that if the change in the density of the material element (fluid element) is small as compared to the magnitudes of the velocity gradient in the .V also if the element moves around, then the flow is said to be incompressible, and it is limited to it only.
So that is all from the alternative way of presenting the continuity equation. Now the next topic is another part of presenting the continuity equation.
The cylindrical polar coordinates system is a way of presenting the terms in (r,,z). it is also known as the cylindrical coordinates system.
In this topic, I will show you how the terms can be explained in a cylindrical system, and it is another way of presenting the continuity equation. So following are some of the important key points related to the topic. Have a look at it:
There can be three-dimensional, one-dimensional and two-dimensional cylindrical coordinates, but here in this topic at the start, I will explain in terms of the two-coordinates system only.
The following are the explanation of the (r, θ):
Here, r shows the radial distance i.e., from the origin to any point (let us say P).
Then there comes , now which shows the angular measurement from the x-axis (if we talk about generally, then is defined as a positive value, and it is in a counterclockwise direction).
The following is a figure that shows the complete explanation of the theoretical background:
There are more important terminologies that need to be defined. So following is the explanation of it:
ur and u are the velocity components
er and e are the unit vectors.
In the case of three-dimensional, there is obviously a z-axis. So in order to show the points, the following diagrams explain well. Have a look at it.
So as you can see that in the three-dimension case, there are two more values, one for the velocity component and the second for the unit vector.
So the following equation shows the coordinate transformation:
r=x2+y2
x=rcos
y=sin
θ=yx
So following is the equation that expresses the continuity equation in terms of cylindrical coordinates.
∂ρ∂t+1r(rρur)r+1r(rρu)+1r(rρuz)z =0
Thank you for reading.
It is one of the most critical topics whenever. It is related to the resistance a fluid faces in motion. A fluid exerts a force on a body in a different direction. Now the main question is, what is drag? And what do we know about it?
The definition of drag is as follows:
The force exerted on a flowing fluid in the direction of fluid flow is called drag.
Some of the essential key points related to the drag are as follows:
In order to elaborate on the drag force through an example. The body is attached to calibrated spring, and it is used to measure the displacement in the direction of flow.
The drag balances are one of those devices that are commonly used to measure the drag force.
It is not wrong to say that the drag force is much similar to the frictional force.
The more reduction in the drag force, the less fuel will be consumed.
An interesting fact about drag is that we can also produce a beneficial effect by drag, so we need to maximize its value. In this scenario, drag helps in pollen flying, usage of parachutes, movement of leaves and much more. These are one of the common examples used in our daily life.
The drag force is a combination of pressure and the wall shear forces in the flow direction.
In order to explain the lift in easy words, let us have a look at the definition.
The component of pressure and the wall shear forces in the normal direction to the fluid flow that tends to move the body in that direction is called lift.
Some of the important key points related to the lift is as follows:
Whenever we are dealing with lift and drag, these both have different responsibilities. In the case of two-dimensional flow, the resultant of the shear and the pressure forces are divided into two important components. The flow in one direction only is the drag force, whereas the normal flow is the lift.
The lift and drag have the equations through we can find the accurate values theatrically and can compare them with the practical ones.
To calculate the differential drag force, we have a differential area dA on a surface PdA and w so the equation will be:
dFD=-P dAcos +wdAsin
The differential lift force is as follows:
dFL=-P dAsin -wdAcos
By integrating the above two equations, we can get the total drag and lift forces that are acting on a body:
Drag Force
FD=∫AdFD=∫A(-Pcos +wsin )dA
Lift Force
FL=∫AdFL=-∫A(Psin +wcos )dA
The above equations show the skin friction (wall shear) and pressure, which contribute to the drag and lift.
The lift and the drag are a strong function of angle attack.
The drag and lift forces depend on the upstream velocity, density, size, shape, and orientation of the body. It is better to work with the dimensionless numbers that are used for the representation of drag and lift characteristics of the body.
The drag and lift coefficient equations are as follows:
Drag Coefficient
CD=FD12V2A
Lift Coefficient
CL=FL12V2A
Here A is the ordinarily Frontal Area.
The topic is related to drag and lift. In order to define the friction and pressure forces, I will explain in few key points:
The net force exerted on a body by fluid in the flow direction drag due to the combined effect of wall shear and pressure forces.
The part of due directly to wall shear stress called skin friction drag.
It is the part that is due directly to the pressure P, called the pressure drag.
The friction and pressure drag coefficients are presented mathematically as follows:
Drag Coefficients Friction
CD, friction=FD, friction12V2A
Drag Coefficient Pressure
CD,pressure=FD,pressure12V2A
So these are the drag coefficients of pressure and friction.
If the values of these coefficients are available, then it becomes easier for us to find the value of the total drag coefficient and total drag force. The formulae of both of these are given as follows:
Total Drag Coefficient
CD=CD,friction+CD,pressure
Total Drag Force
FD=FD,friction+FD,pressure
The friction of drag is the main component of the wall shear force, and this force is in the direction of flow.
In the case of a flat surface, the value of friction drag is zero, and it is normal to the flow direction. The value is said to be the maximum for a flat surface parallel to the flow.
With the increase in the viscosity, there is an increase in the drag.
Another exciting fact about it is that Reynold’s Number is inversely proportional to the viscosity of a fluid. So when the value of Reynold’s number is high, then the value of the total drag or the friction drag is less.
When the value of Reynold’s number is less, it is due to the friction drag and mostly happens in the streamlined bodies.
the bodies having a large surface area have a significant friction drag value. But it is independent of the surface roughness.
In the case of pressure drag, it is proportional to the frontal area.
The value of drag pressure for the blunt bodies is maximum; for the streamlined bodies is less, and in the case of the thin flat plates that are parallel to the flow, the value is zero.
It is also one of the important topics of drag.
The following are some important key points related to reducing drag by streamlining:
As I have discussed earlier that the drag pressure in the case of streamlined bodies is less.
Decrease the drag for a streamlined body by reducing the flow separation, ultimately reducing the pressure drag.
The streamlining delay the boundary layer separation resulting in a decrease in the pressure drag and an increase in friction drag.
The following diagram shows the difference in the values of friction, pressure, and total drag coefficients of a streamlined strut.
As you can see from the diagram, the value of total drag at minimum is D/L=0.25.
The drag coefficient value will be five times in the case of a circular cylinder having the same thickness as the streamlined shape.
In the case of an elliptical cylinder shape, the value of the drag coefficient is less. The elliptical cylinder shape is considered the perfect example for defining the effect of streamlining on a drag coefficient.
I will define flow separation extensively, so the following is the definition of it.
The fluid has high velocity when force flows over a curved body. Similarly, fluid can climb uphill on a curved surface without distraction.
At high velocities, the fluid stream detaches itself from the body’s surface, known as flow separation.
A flow can be separated from a surface when fully submerged in an immersed gas or liquid.
There are many essential terminologies for this topic, and the following are some important key points, equations, and definitions for the parallel flow over the flat surface. So let us start.
The following diagram shows a flat plate on which a fluid has flowed.
Taking this diagram as a reference, I will explain the whole topic through this.
Here, in this flat plate, the x-axis is measured along the plate surface (starting from the leading edge of the plate in the direction the fluid is flowing), whereas the y-coordinate is measured from the surface in the normal direction.
The surface’s velocity is equal to the velocity of the fluid that travels along the x-coordinate.
As you can see through the diagram, for our convenience, we have assumed that the fluid is in adjacent layers and they are piled onto one another
By doing so, the velocity of the first layer of fluid adjacent to the plate becomes zero, and this is due to the no-slip condition.
The first layer impacts the other layers by slowing the motion of particles of other different. And the process goes on as the layer slows down the next layer’s molecules.
The presence of the layer is then felt up to some normal distance (), from the plate, beyond which the free-stream velocity remains unchanged.
There are some critical regions and layers present on this layer, and they are defined as follows:
Velocity Boundary Layer
It is the region of the flow that is above the plate bounded by normal distance () in which the effect of the viscous shearing force caused by fluid viscosity is felt.
Irrotational Flow Region
It is the region where the frictional effect is negligible, and the velocity is constant.
The thickness of the boundary layer (δ) is the distance y from the surface at which u=0.99V.
There is a hypothetical line that is present on the layer (u=0.99V) that divides the flow into two regions, and they are named as follows:
Boundary Layer Region
Irrotational Flow Region
In this flat plate parallel to the flow condition, the pressure drag is zero, and the drag coefficient equals the friction drag coefficient. Mathematically we can present it as follows:
CD=CD,friction=Cf
Here Cf is the drag friction coefficient.
The equation for calculating the friction force on the plate is as follows:
FD=Ff=12CfAρV2
Here the A is the surface area of the plate.
From the diagram, you have observed that the velocity profile is in laminar and turbulent flows.
Also, the turbulent is much fuller than the laminar one. As it has four regions, and they are named as follows:
Viscous Sublayer
Buffer Layer
Overlap Layer
Turbulent Layer
The transition of laminar to turbulent flow is dependent on the geometry of the surface, roughness, upstream velocity, surface temperature, and many things.
The Reynold’s number at a distance x from the leading edge of a flat plate is as follows:
Rex=ρVx=Vxv
In the case of a flat smooth plate, the transition from a laminar to a turbulent flow starts at Reynold’s number RE≅1×105. The flow does not become turbulent until the value of Reynold’s number reaches RE≅3×106
Friction Coefficient
The following are some key points related to the friction coefficients:
In the case of laminar flow, we can calculate the value of friction coefficients by using the law of conservation of mass and momentum.
In the case of turbulent flow, it should be calculated experimentally and should be expressed in the empirical correlation.
The drag force for the whole surface can be calculated by using the average friction coefficient value.
In some cases, if we want drag force for a specific location, then in this condition, we must know the local value of the friction coefficient.
If we have the value of local values, then it becomes easy for us to calculate the average friction coefficient values:
Cf=1L0LCf,xdx
It is one of the important related to lift and drag. So following are the important key points related to the flow over the cylinder and spheres:
In our daily life, if we look around, there are multiple examples of it. In tubes (shell and tube heat exchanger) involves the internal and external flow over the tubes.
In sports, cricket, soccer, and tennis balls are the best examples of this topic.
For calculating the circular cylinder or sphere, the external diameter is taken as D.
In Reynold’s number, the formula is as follows:
Re=VDv
Here the V stands for the uniform velocity of the fluid as it approaches the cylinder and sphere.
Here, the value of the critical Reynold’s number is Recr≅2×105.
The change in total drag coefficient value is observed for the flow of cylinders and spheres.
It is not wrong to say that the drag force is due to the friction drag at the low value of Reynold’s number (Re< 10) and in the case of pressure drag at a higher value of Reynold’s number (Re>5000).
The following diagram shows the separation of the laminar boundary layer with the turbulent over a cylinder.
Effect of Surface Roughness
In the previous topic, I discussed this thing that the impact of having a surface makes a huge difference. So while discussing the cylinders and the spheres, it becomes important to discuss them in detail.
The following are some essential key points related to the topic:
The increase in surface roughness increases the drag coefficient in the case of turbulent flow.
For the streamlined case, it is also the same. But for the spheres and the cylinders, the increase in the roughness of the surface decreases the coefficient of drag. This means they have an indirect relationship.
The following diagram shows the indirect relation for cylinders and spheres.
The indirect relation is done by tripping the boundary layer into turbulence at the lower value of Reynold’s number. The result is that the fluid is close in behind the body, reducing the pressure drag force.
The value of Reynold’s number is Re≅2×105, and the value of the drag coefficient is CD≅0.1 in the case of a rough surface along with D=0.0015. In the case of a smooth surface, the values changes, and they become CD≅0.5.
The value of Reynold’s number for the rough sphere is Re≅106, and the drag coefficient value is CD≅0.4.
So the value of the drag coefficient for a smooth sphere is CD≅0.1.
The rougher the sphere will become, the more drag will also increase.
In order to exemplify the values, let us take an example of a golf ball. The velocity value ranges from 15 to 150m/s for the golf ball, and the value of Reynold’s number is 4×105,.
Lift
At the start of the article, I have already discussed what lift is. Here in this topic, I will explain extensively about the lift and the mathematical equation.
In order to explain the topic in a symmetric manner, I will explain it in key points, and these are as follows:
As you know that lift is the component of the net force, and this net force is because of the viscous and pressure force.
The coefficient of the lift is explained as follows:
CL=FL12V2A
The A here presents the planform area, and this area is viewed by someone that is looking at it from above in a direction normal to the body.
The V is the upstream velocity.
We will consider the airfoil with a width b and chord length c and the planform area as A=bc, respectively.
The following is the diagram that shows the airfoil structure.
Here, there is a term called wingspan or span. It is the distance between the two ends of the foil.
In the case of aircraft, the wingspan is the total distance between the tips of two wings.
Another important term is wing loading. It is the average lift per unit planform area FLA.
The airplanes are all based on the lift.
The purpose of discussing the lift in detail is to know how airfoils are designed and how they generate lift by keeping the value of drag minimum.
The streamlined bodies, such as airfoils that intends to generate the lift, have a negligible lift, and the wall shear is parallel to the surface.
I will show you the pictorial representation of the irrotational and actual flow past the non-symmetrical two-dimensional airfoils.
The following diagram shows the irrotational flow past a symmetrical airfoil (here the lift is zero).
The following diagram shows irrotational flow past a non-symmetrical airfoil (having zero lift).
The following diagram shows the actual flow past a non-symmetrical airfoil, and here the lift is positive.
Hope you enjoy reading the article. I have tried my best to explain you every point in easy words. Thank you for reading.
Hello Friends. I hope you are doing great. Here I am with another exciting topic of fluid mechanics, i.e. flow over bodies. In this article, I will explain the flow of fluids, the flow rate, their nature, the flow in pipes and much more. Fluid mechanics is all related to the fluid and its nature. I will discuss the forces that are on the body that is immersed in a fluid and the flow that is over the body. As the title shows, the main emphasis will be on the lift and drag forces. Moreover, the external and the internal flow will also be discussed in this article. And I am sure that you will enjoy reading this article. So without wasting any time, let us start.
I will start with an introduction to fluid flows.
In this article, our focus will be the fluid flow over the bodies immersed in the fluid. There are six different types of flows, and they are named as follows:
Steady and Unsteady Flow
Uniform and Non-Uniform Flow
One, two and three-dimensional Flow
Rotational or Irrotational Flow
Laminar and Turbulent Flow
Compressible and Incompressible Flow
Before discussing them extensively, I will briefly explain the external flow.
Let me explain the external flow in critical points:
We will take two situations. The first situation says that the body is at rest, and the fluid flow moves over it, and the second one says that the body is moving through some quiescent fluid.
If you look around, there are building standing still, and the wind is blowing over the building. This is the case when the body is stationary
The second condition is that the car is moving through the air.
So now, these are two different scenarios, but the main thing that matters is the relative motion of the fluid and the body. So, such motions are analysed by fixing the coordinate system on the body, called External Flow or Flow over the body.
Now moving towards the six types of flows, let us start explaining them one by one.
The definition of the steady flow is as follows:
The steady flow is where pressure, velocity, and cross-section differ from one point to another, and it does not change with time.
Some of the essential key point about the steady flow is as follows:
There are changes in the flow, but the change is so small that one particular parameter remains constant for a fixed period. But we can say that it is an ideal case because, in the actual case, there are very few chances that the parameters can remain constant.
The definition of the unsteady flow is as follows:
Changes in parameters at some stage can make the floe unstable. In practical cases, there is always a change in values of pressure and velocity values. Average values are constant; then, the flow is constant.
Some of the essential key point about the unsteady flow is as follows:
The unstable flow is said to be uniform and non-uniform both.
In the case of uniform flow, the cross-sectional area of fluid flow through the stream is said to be constant.
The definition of the uniform flow is as follows:
The distance along the flow path is constant then the flow parameter is also said to be constant. The fluid flow is called uniform flow.
Some of the essential key points about the uniform flow are as follows:
The cross-sectional area in the case of uniform flow is constant.
One of the best examples of uniform flow is the flow through the pipeline.
The definition of the non-uniform flow is as follows:
The non-uniform fluid flow is due to the variations in the flow parameters, varying at different points on the flow path.
Some of the essential key points about the non-uniform flow are as follows:
It is evident, as the names show, that the parameters do not remain constant. A change in velocity can be observed; ultimately, the flow is also said to be non-uniform.
In practical cases, the flow near the solid boundary is said to be a non-uniform flow.
The term has three types of fluid flows.
Starting the one-dimensional flow its definition is as follows:
The flow that travels in one dimension and changes parameters such as pressure, velocity, depth etc., in one flow direction only is said to be one-dimensional flow.
Some of the essential key points about the one-dimensional flow are as follows:
The change in parameters in one direction at a given moment is considered a one-dimensional flow.
There are many chances that the flow can be unstable if the parameter alters in time, but it is still not across the cross-section.
The definition of the two-dimensional flow is as follows:
The flow parameters differ in the flow direction, and in one direction in the right angles, the flow is then said to be two-dimensional flow.
Some of the essential key points about the two-dimensional flow are as follows:
Toto elaborates on the two-dimensional flow; following diagram explains the flow well. Have a look at it.
The flow is either in the x direction or y. there is no change in the z-direction.
In two-dimensional flow, streamlines are usually curved in one plane and the same on every parallel plane.
The definition of the three dimensional flow:
The element of the fluid moves in three dimensions (translation, rate of deformation and rotation) in space. Such a kind is called the three-dimensional flow.
Some of the important key points related to the three-dimensional flow is as follows:
The following is the diagram that shows the three-dimensional flow:
Let us start with the rotational flow:
The definition of the rotational flow is as follows:
The flow in which the fluid particles rotate on their axis while along the flow line is called the rotational fluid flow.
The definition of fluid flow is as follows:
The flow in which fluid particles do not rotate in their own axis when theyw along the flow lines.
The visual representation of both flows is as follows;
The following is the diagram that shows the rotational fluid flow:
The following diagram shows the irrotational fluid flow:
Let us start with laminar flow
The definition of the laminar flow is as follows:
The flow in which fluid particles move in a well define path and the streamlines straight and parallel. Such kind of flow is called laminar flow.
Some of the important key point related to the laminar flow is as follows:
The pictorial representation of the laminar flow is as follows:
The definition of the turbulent flow is as follows:
The flow in which the fluid particles do not move in a well define path and it lead to high energy losses throughout.
Some of the important key point related to the turbulent flow is as follows:
The pictorial representation of the turbulent flow is as follows:
The definition of the compressible fluid flow is as follows:
The flow in which the density of fluid varies from one point to another point (not constant) is called the compressible flow.
The pictorial representation of the compressible flow is as follows:
The definition of incompressible flow is as follows:
The flow in which the density of the fluid flow is constant is said to be incompressible flow.
The pictorial representation of the incompressible flow is as follows:
That is all from the types of fluid flow. Now, we will move towards the main topic, i.e. lift and drag. Let us start.
Greetings, and welcome to another tutorial in our series on the raspberry pi 4 Python programming. The previous guide covered the basics of transmitting data over the radio using the nrf24l01 chip in Pi 4. We also learned about interfacing Arduino and raspberry pi 4 and sending radio signals between the two devices. However, this tutorial will walk you through building a Raspberry Pi-based mobile phone with a microphone and speaker for making and receiving calls and reading text messages (SMS). This Project also serves as a proper GSM Module for the Raspberry Pi interface, with all the necessary Code to run the most fundamental features of any modern smartphone. First, we will understand what gsm is, its architecture and how it works, then we will learn how to program it in our pi 4; therefore, let us begin.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | Jumper Wires | Amazon | Buy Now | |
| 2 | LCD 16x2 | Amazon | Buy Now | |
| 3 | Raspberry Pi 4 | Amazon | Buy Now | |
Raspberry Pi 4
GSM Module
16x2 LCD
4 *4 Keypad
10k pot
Breadboard
Connecting jumper wire
Power supply
Speaker
Microphone
SIM Card
Loudspeaker
The acronym "GSM" refers to the "global system for mobile communication" and is the name of a type of mobile communication modem (GSM). Bell Labs was responsible for conceptualizing GSM in the 1970s. It's one of the most common forms of mobile communication around the globe. The 850MegaHertz, 900MegaHertz, 1800 Megahertz, and 1900 Megahertz frequency bands are utilized by GSM networks, which are part of an open and digital mobile network used to carry voice and data services.
Using the telecommunications method of multiple time division access (TDMA), GSM technology was created as a digital system. For transmission, a GSM converts analog signals to digital ones, compresses them further and delivers them through a channel sharing bandwidth with two data streams from separate clients. The data rates transported by the digital system range from 64 kilobytes per second to 120 Megabytes per second.
In a GSM network, macro, micro, and umbrella cells coexist. The implementation context determines the specifics of each cell. The macro, micro, and umbrella cell sizes are in use in a GSM network. Each cell may have a different range of coverage depending on the setting.
Time-division multiple access (TDMA) works by giving each user a specific amount of time to transmit on the same frequency. It's flexible, supporting data rates from 64kbps to 120Mbps and allowing for clear voice communications.
The following are the primary components of the GSM architecture.
Connectivity and Switching Infrastructure (NSS)
All three of these components—the Base Station (BS), the Mobile Station (MS), and the Operations and Maintenance Subsystem (OSS)—are necessary for proper communication (OSS)
Each component of the GSM system design contributes to what is collectively called the core system/network. In this case, the mobile network system is primarily controlled and interfaced with via a data network consisting of several different components. Listed below are some of the most crucial elements of the underlying network.
One of the essential parts of a GSM network is its core network, where the Mobile Switching Center (MSC) resides. This MSC performs the same functions as a common switching node in an ISDN or PSTN. Still, it provides additional features to accommodate mobile users' requirements, such as authentication, registration, inter-MSC handovers, call localization, and routing.
In addition, it gives users an advantage in connecting their mobile phone networks to the PSTN (public switched telephone network) for making and receiving landline calls. To facilitate mobile-to-mobile calls across different networks, interfaces to all other switched telephone networks ( PSTN center servers are given.
Every subscriber's administrative details, including their last known location, are stored in this HLR database. This manner, calls can be routed over the GSM network to the appropriate mobile switch base station. If a call comes in when an operator has their phone turned on, the network can determine which base transmitter station the call is coming from and link it to the correct phone.
When the phone is turned on but not being used, it nevertheless registers to ensure the HLR system is aware of its current location. Each network has a single HLR, which may be physically split across several data centers for practical reasons.
To facilitate the VLR's desired services for the individual subscriber, it incorporates data from the HLR network. It is possible to run the visitor coordinates register independently, but it is most commonly implemented as a core component of the MSC. Because of this, getting access is more manageable, and it takes less time overall.
The Equipment Identity Register (EIR) is the part of the network infrastructure in charge of deciding whether or not certain pieces of mobile equipment are allowed access. The International Mobile Equipment Identification (IMEI) numbers uniquely identify each mobile technology work.
This IMEI number is permanently embedded within the mobile device and checked by the network after registration. Depending on the data in the EIR, the mobile phone may be given one of three possible network access states: allowed, banned, or monitored.
When users insert their SIM card into their phone, the secret key is stored in a secure file known as the AUC (authentication center). The AUC sees the extensive application as a radio channel coding and verification standard.
In the absence of location information for the mobile station (MS), a call placed by a ME terminates with the GMSC (Gateway Mobile Switching Centre). Using the Mobile Subscriber Identifier Service Data Number (MSISDN) and the HLR, the GMSC can locate the specific MSC that has been visited and connect the call to the appropriate location. It's unclear what the "MSC" part of GMSC stands for, as the gateway procedure does not require relating to an MSC.
Both SMS-Gateways are referred to collectively as the SMS gateway in the GSM specifications. The messages passing via these gateways are directed in various ways.
Sending a short message to mobile equipment (ME) requires the usage of the Short Messaging Service Gateway Switching Center. Short messages sent over a mobile network are routed through the SMS Inter-Working Switching Center. While the SMS-primary GMSC's function concerns the GMSC, the SMS-IWMSC serves as a constant endpoint for access to the Short Message Service Centre.
These were the primary nodes in the GSM system's infrastructure. While they frequently shared physical space, the entire middle network would sometimes be broadcast throughout the country. In the event of a failure, it will provide a degree of leeway.
The connection point between the mobile node and the broader network infrastructure. The radio transceivers and protocol management for mobile devices are housed in the Base Transceiver Station. In addition, a Base Station Controller manages the Base Transceiver and serves as a bridge between mobile devices and the mobile switching hub.
The network subsystem handles connectivity between the network and the mobile stations. The Phone Service Switch Centre is the backbone of the Network Subsystem, allowing users to connect to other networks (ISDN, PSTN, etc.). The GSM system's ability to route calls and allow for roaming depends on two additional components, the Home Location Record and the guest Location Record.
In addition, it stores the Equipment Identity Register, which keeps track of all the mobile devices and their associated IMEI numbers. The acronym IMEI refers to the unique identifier for mobile devices worldwide.
In the second generation of GSM network design, the mobile devices communicate with the BSS, or Base Station Subsystem. These components comprise this subsystem, and each will be examined.
As part of a GSM network, the radio Tx, Rx, and their associated antennas make up the base Transceiver Station, which is used for transmitting, receiving, and communicating directly through mobiles. The base station is the central component of each cell, and it communicates with mobile devices using an interface known as the Um interface and related protocols.
The base station controller (BSC) is employed for the following step back into GSM technology. This controller is typically co-located within one of the base transceiver stations it controls. This controller handles radio resource management, including channel allocation and handover between base station groups. Over the Abis interface, it communicates with the BTSs.
The acceptable radio technology is used by the GSM network's subsystems component in the ground station to ensure that multiple operators can utilize the system at the same time. Each base station can support many operators because each channel can support up to eight users.
The network provider strategically places these to ensure comprehensive coverage. A base station, sometimes known as a "cell," can surround this space. Signals can't be prevented from bleeding into neighbouring cells, and the channels used in one don't transfer to the next.
Mobile phones include a transceiver, a display, and a CPU, all of which are network-connected and operated using a SIM card. In a GSM mobile transmission medium, the operator monitors and controls the mobile station or mobile equipment, which are most commonly represented by cell phones. Their size has shrunk significantly while their functionality has skyrocketed. The benefit of a much longer interval between charges is still another advantage. Phone hardware and the subscriber identity module (SIM) are two of many components.
A mobile device's hardware consists of its primary components, such as the housing, screen, battery, and electronics used to generate the signal and process the signal receiver before transmission. The IMEI is a unique number assigned to each mobile device. This feature can be permanently programmed into a phone throughout its manufacturing process. During the registration process, the network accesses this database to see if the device has been flagged as stolen.
A user's identity on the network is stored in the information contained in their SIMcard. It also includes other data, such as the IMSI number. With this IMSI stored in the Sim, the phone user could easily switch phones by swapping SIM cards. As a result, if switching to a new mobile phone were simple and didn't require a unique phone number, more people would do it, generating more revenue for network operators and contributing to GSM's overall economic triumph.
The OSS is an integral aspect of any functional GSM network. The NSS and BSC parts are linked here. The GSM network and BSS traffic load are the primary areas of focus for this OSS. It is worth noting that some preservation responsibilities are relocated to the base station controller to lower the maintenance expense of the system when the amount of BS increases through the consumer population growth.
The 2G GSM network architecture is predicated on a rational functioning method. This approach is remarkably straightforward compared to today's mobile network architectures, which rely on software-defined units to facilitate highly adaptable operations. However, the 2G GSM architecture will show how the necessary voice and essential operational functions are organized.
The following are some of the functions provided by the GSM module.
Enhanced spectrum efficiency
Features including "international roaming," "integrated services digital network" (ISDN) compatibility, and "support for future services" are also included.
High-quality voice communications; encrypted phone conversations;
Features like a programmable alarm clock, high-quality voice communication, a fixed calling number, a real-time clock, and the ability to send and receive SMS messages are all standard on modern smartphones (SMS)
As a result of its rigorous security measures, the GSM system is currently the safest available for use in the telecommunications industry. Call privacy and subscriber anonymity for GSM users are only protected during transmission, but this is still a massive step toward attaining end-to-end security.
In either its mobile phone or modem form, a Global System for Mobile Communications (GSM) modem enables two computers or processors to connect across a network. A SIM card is needed to run a GSM modem, and it can only be used within the coverage area the network provider has paid for. It has serial, USB, and Bluetooth connectivity options for linking to a personal computer.
Any regular GSM cell phone can double as a GSM modem if you have a suitable cable and driver installed on your PC. It would be best if you used a GSM modem instead of a GSM cell phone. The GSM modem is helpful in many devices, including POS terminals, inventory management systems, surveillance cameras, weather stations, and GPRS-mode remote data loggers.
Below is a circuit showing how to connect a GSM modem to the MC using the level-shifting IC Max232. When a numeric command is received by short message service (SMS) from any mobile device, the SIM card-mounted GSM modem transfers that information to the MC via serial connection. The GSM modem is programmed to respond to the order "STOP" by producing an MC output, the point which is utilized to deactivate the ignition switch.
If the input is driven low, the GSM modem will send a predetermined message (in this case, "ALERT") to the user. A 162 LCD screen displays the entirety of the procedure.
We have utilized a GSM module and a Raspberry Pi 4 to manage the entire system and interface its many parts in this Project. You can input data of any kind, including phone numbers, text messages, and phone calls, read and respond to text messages, and more, using a 4x4 alphanumeric keypad. The SIM900A GSM module connects mobile phones to wireless networks for making and receiving calls and sending and receiving text messages. We've integrated a microphone, a loudspeaker for making and receiving voice calls, and a 16 * 2 liquid crystal displays information like menu options and alarms.
With alphanumeric input, you can use the same keyboard to type in both numbers and letters. For the Code we used to allow alphabets in addition to numbers in this method, scroll down to the "Code in Code" section.
It's simple to put this plan into action. The alphanumeric keypad is used for all functions. Below you'll find a link to the complete Code and a demonstration video. This section will elaborate on the four aspects of the listed projects.
The Pi 4 phone we built requires us to press the letter "C" and provide the cellphone number we wish to call. We'll use an alphanumeric keyboard to enter the number. Once the correct number has been entered, we must hit "C" again. The AT command is now processed by pi 4 to connect the call to a specified number.
ATDxxxxxxxxxx; <Enter> where xxxxxxxxx is entered Mobile Number.
Answering a phone call is simple. When a call comes into the SIM number stored in the GSM Module of your system, the LCD will display the message "Incoming..." along with the caller's number. All that's left to do is hit the 'A' key to answer the call. Pi 4 will send the following command to the GSM Module when the "A" button is pressed:
ATA <enter>
Pressing "D" on our Raspberry Pi phone allows us to send a text message. To whom (or what) should we address the SMS message that the system has just requested? Once the number has been entered, pressing "D" again will prompt the LCD to request a message. To send an SMS, enter the message using the keypad as you would with any other mobile device, and then hit the 'D' key again. Raspberry Pi can send SMS with the following command:
AT+CMGF=1 <enter>
AT+CMGS=”xxxxxxxxxx” <enter> where: xxxxxxxxxx is entered mobile number
Even this component is easy to use. Here, the SIM card is used to receive SMS messages from the GSM. The Raspberry Pi also keeps a close eye on the UART SMS signal. New notes are shown by the LCD displaying the text "New message," and reading them is as simple as pressing the "B" key. This is an SMS Received signal:
+CMTI: "SM," 6 Where 6 is the message location where it is stored in the SIM card.
When the RPi detects the 'SMS received' signal, it will get the SMS storage location and instruct the Global system for mobile to read the message. Moreover, the LCD will flash the words "New Message" in a prominent location.
AT+CMGR=<SMS stored location><enter>
The GSM now delivers the saved message to the Raspberry Pi, and the Pi, having extracted the primary SMS, shows it on the LCD. When it comes to MIC and Speaker, there is no secret code.
The GPIO pins of the Raspberry Pi are wired to the RS, EN, D4, D5, D6, and D7 pins of the 16 * 2 liquid crystal display. A direct connection is made between the GSM module's Rx and Tx pins and the Raspberry Pi's Tx and Rx pins. Connectors R1, R2, R3, and R4 of a 4 * 4 keypad are connected to GPIOs 12, 16, 20, and 21, whereas pins C1, C2, C3, and C4 are connected to GPIOs 26, 19, 13, and 6. If you want to boost the audio volume from the GSM Module, you can join the microphone directly to the mic+ and mic- pins and the loudspeaker to the sp+ and sp- pins. The loudspeaker can be connected directly to the GSM module without using the Audio Amplifier circuit.
This Pi 4 mobile phone's programming interface may be challenging to novices—the programming language of choice for this Project is Python.
Here, we define the keypad() function to be used with a basic numeric keypad. We've also added a def alpha keypad(): for typing alphabets so that you may use the same keypad for both purposes. To make it compatible with the Arduino keypad library, we've given this keypad a wide range of new capabilities. This keypad only takes 10 presses to enter a whole string of text or a numeric value.
For example, if we push key 2 (abc2) once, the LCD will display the letter 'a.' If we press it again, the letter 'b' will take its place, and if we hit it three more times, the letter 'c' will appear in the same spot. After holding down a key for a short time, the LCD pointer will advance to the following available location. We can now proceed to the next character or number. Any other keys can be processed in the same way.
def keypad():
for j in range(4):
gpio.setup(COL[j], gpio.OUT)
gpio.output(COL[j], 0)
ch=0
for i in range(4):
if gpio.input(ROW[i])==0:
ch=MATRIX[i][j]
return ch
while (gpio.input(ROW[i]) == 0):
pass
gpio.output(COL[j],1)
def alphaKeypad():
lcdclear()
setCursor(x,y)
lcdcmd(0x0f)
msg=""
while 1:
key=0
count=0
key=keypad()
if key == '1':
ind=0
maxInd=6
Key='1'
getChar(Key, ind, maxInd)
.... .....
..... .....
To begin, we have declared the pins for the liquid crystal display, the keypad, and other components, as well as included the necessary libraries in this python script:
import RPi.GPIO as gpio
import serial
import time
msg=""
alpha="1!@.,:?ABC2DEF3GHI4JKL5MNO6PQRS7TUV8WXYZ90 *#"
x=0
y=0
MATRIX = [
['1','2','3','A'],
['4','5','6','B'],
['7','8','9','C'],
['*','0','#','D']
]
ROW = [21,20,16,12]
COL = [26,19,13,6]
... .....
..... .....
The pins need to be pointed in the proper direction.
gpio.setwarnings(False)
gpio.setmode(gpio.BCM)
gpio.setup(RS, gpio.OUT)
gpio.setup(EN, gpio.OUT)
gpio.setup(D4, gpio.OUT)
gpio.setup(D5, gpio.OUT)
gpio.setup(D6, gpio.OUT)
gpio.setup(D7, gpio.OUT)
gpio.setup(led, gpio.OUT)
gpio.setup(buz, gpio.OUT)
gpio.setup(m11, gpio.OUT)
gpio.setup(m12, gpio.OUT)
gpio.setup(button, gpio.IN)
gpio.output(led , 0)
gpio.output(buz , 0)
gpio.output(m11 , 0)
gpio.output(m12 , 0)
To begin Serial communication, follow the steps below.
Serial = serial.Serial("/dev/ttyS0", baudrate=9600, timeout=2)
We must now create a liquid crystal display driving function. The def lcdcmd(ch): and def lcdwrite(ch): functions are used to deliver commands and data to the LCD, respectively. The liquid crystal display may also be cleared with def lcdclear(), the cursor position can be set with def setCursor(x,y), and a string can be sent to the liquid crystal display with def lcdprint(Str).
def lcdcmd(ch):
gpio.output(RS, 0)
gpio.output(D4, 0)
gpio.output(D5, 0)
gpio.output(D6, 0)
gpio.output(D7, 0)
if ch&0x10==0x10:
gpio.output(D4, 1)
.... .....
..... ....
def lcdwrite(ch):
gpio.output(RS, 1)
gpio.output(D4, 0)
gpio.output(D5, 0)
gpio.output(D6, 0)
gpio.output(D7, 0)
if ch&0x10==0x10:
gpio.output(D4, 1)
if ch&0x20==0x20:
gpio.output(D5, 1)
.... .....
..... ....
def lcdclear():
lcdcmd(0x01)
def lcdprint(Str):
l=0;
l=len(Str)
for i in range(l):
lcdwrite(ord(Str[i]))
def setCursor(x,y):
if y == 0:
n=128+x
elif y == 1:
n=192+x
lcdcmd(n)
Next, we'll need to code some features for interacting with text messages, phone calls, and incoming calls.
The call is placed using the function def call():. Also, the LCD can display the receiving message and number via the function def receiveCall(data):. Finally, the call is answered with def attendCall():.
The message is composed and sent using the alphaKeypad() method, accessed via the def sendSMS(): function. The SMS is received, and its location is retrieved using the def receive SMS(data) function. And finally, the LCD gets updated with the message thanks to def readSMS(index:).
All of the operations mentioned above are included in the Code that follows.
import RPi.GPIO as gpio
import serial
import time
msg=""
# 0 7 11 15 19 23 27 32 36 414244 ROLL45
alpha="1!@.,:?ABC2DEF3GHI4JKL5MNO6PQRS7TUV8WXYZ90 *#"
x=0
y=0
MATRIX = [
['1','2','3','A'],
['4','5','6','B'],
['7','8','9','C'],
['*','0','#','D']
]
ROW = [21,20,16,12]
COL = [26,19,13,6]
moNum=['0','0','0','0','0','0','0','0','0','0']
m11=17
m12=27
led=5
buz=26
button=19
RS =18
EN =23
D4 =24
D5 =25
D6 =8
D7 =7
HIGH=1
LOW=0
gpio.setwarnings(False)
gpio.setmode(gpio.BCM)
gpio.setup(RS, gpio.OUT)
gpio.setup(EN, gpio.OUT)
gpio.setup(D4, gpio.OUT)
gpio.setup(D5, gpio.OUT)
gpio.setup(D6, gpio.OUT)
gpio.setup(D7, gpio.OUT)
gpio.setup(led, gpio.OUT)
gpio.setup(buz, gpio.OUT)
gpio.setup(m11, gpio.OUT)
gpio.setup(m12, gpio.OUT)
gpio.setup(button, gpio.IN)
gpio.output(led , 0)
gpio.output(buz , 0)
gpio.output(m11 , 0)
gpio.output(m12 , 0)
for j in range(4):
gpio.setup(COL[j], gpio.OUT)
gpio.setup(COL[j],1)
for i in range (4):
gpio.setup(ROW[i],gpio.IN,pull_up_down=gpio.PUD_UP)
Serial = serial.Serial("/dev/ttyS0", baudrate=9600, timeout=2)
data=""
def begin():
lcdcmd(0x33)
lcdcmd(0x32)
lcdcmd(0x06)
lcdcmd(0x0C)
lcdcmd(0x28)
lcdcmd(0x01)
time.sleep(0.0005)
def lcdcmd(ch):
gpio.output(RS, 0)
gpio.output(D4, 0)
gpio.output(D5, 0)
gpio.output(D6, 0)
gpio.output(D7, 0)
if ch&0x10==0x10:
gpio.output(D4, 1)
if ch&0x20==0x20:
gpio.output(D5, 1)
if ch&0x40==0x40:
gpio.output(D6, 1)
if ch&0x80==0x80:
gpio.output(D7, 1)
gpio.output(EN, 1)
time.sleep(0.005)
gpio.output(EN, 0)
# Low bits
gpio.output(D4, 0)
gpio.output(D5, 0)
gpio.output(D6, 0)
gpio.output(D7, 0)
if ch&0x01==0x01:
gpio.output(D4, 1)
if ch&0x02==0x02:
gpio.output(D5, 1)
if ch&0x04==0x04:
gpio.output(D6, 1)
if ch&0x08==0x08:
gpio.output(D7, 1)
gpio.output(EN, 1)
time.sleep(0.005)
gpio.output(EN, 0)
def lcdwrite(ch):
gpio.output(RS, 1)
gpio.output(D4, 0)
gpio.output(D5, 0)
gpio.output(D6, 0)
gpio.output(D7, 0)
if ch&0x10==0x10:
gpio.output(D4, 1)
if ch&0x20==0x20:
gpio.output(D5, 1)
if ch&0x40==0x40:
gpio.output(D6, 1)
if ch&0x80==0x80:
gpio.output(D7, 1)
gpio.output(EN, 1)
time.sleep(0.005)
gpio.output(EN, 0)
# Low bits
gpio.output(D4, 0)
gpio.output(D5, 0)
gpio.output(D6, 0)
gpio.output(D7, 0)
if ch&0x01==0x01:
gpio.output(D4, 1)
if ch&0x02==0x02:
gpio.output(D5, 1)
if ch&0x04==0x04:
gpio.output(D6, 1)
if ch&0x08==0x08:
gpio.output(D7, 1)
gpio.output(EN, 1)
time.sleep(0.005)
gpio.output(EN, 0)
def lcdclear():
lcdcmd(0x01)
def lcdprint(Str):
l=0;
l=len(Str)
for i in range(l):
lcdwrite(ord(Str[i]))
def setCursor(x,y):
if y == 0:
n=128+x
elif y == 1:
n=192+x
lcdcmd(n)
def keypad():
for j in range(4):
gpio.setup(COL[j], gpio.OUT)
gpio.output(COL[j], 0)
ch=0
for i in range(4):
if gpio.input(ROW[i])==0:
ch=MATRIX[i][j]
#lcdwrite(ord(ch))
# print "Key Pressed:",ch
# time.sleep(2)
return ch
while (gpio.input(ROW[i]) == 0):
pass
gpio.output(COL[j],1)
# callNum[n]=ch
def serialEvent():
data = Serial.read(20)
#if data != '\0':
print data
data=""
def gsmInit():
lcdclear()
lcdprint("Finding Module");
time.sleep(1)
while 1:
data=""
Serial.write("AT\r");
data=Serial.read(10)
print data
r=data.find("OK")
if r>=0:
break
time.sleep(0.5)
while 1:
data=""
Serial.write("AT+CLIP=1\r");
data=Serial.read(10)
print data
r=data.find("OK")
if r>=0:
break
time.sleep(0.5)
lcdclear()
lcdprint("Finding Network")
time.sleep(1)
while 1:
data=""
Serial.flush()
Serial.write("AT+CPIN?\r");
data=Serial.read(30)
print data
r=data.find("READY")
if r>=0:
break
time.sleep(0.5)
lcdclear()
lcdprint("Finding Operator")
time.sleep(1)
while 1:
data=""
Serial.flush()
Serial.read(20)
Serial.write("AT+COPS?\r");
data=Serial.read(40)
#print data
r=data.find("+COPS:")
if r>=0:
l1=data.find(",\"")+2
l2=data.find("\"\r")
operator=data[l1:l2]
lcdclear()
lcdprint(operator)
time.sleep(3)
print operator
break;
time.sleep(0.5)
Serial.write("AT+CMGF=1\r");
time.sleep(0.5)
# Serial.write("AT+CNMI=2,2,0,0,0\r");
# time.sleep(0.5)
Serial.write("AT+CSMP=17,167,0,0\r");
time.sleep(0.5)
def receiveCall(data):
inNumber=""
r=data.find("+CLIP:")
if r>0:
inNumber=""
inNumber=data[r+8:r+21]
lcdclear()
lcdprint("incoming")
setCursor(0,1)
lcdprint(inNumber)
time.sleep(1)
return 1
def receive SMS(data):
print data
r=data.find("\",")
print r
if r>0:
if data[r+4] == "\r":
smsNum=data[r+2:r+4]
elif data[r+3] == "\r":
smsNum=data[r+2]
elif data[r+5] == "\r":
smsNum=data[r+2:r+5]
else:
print "else"
print smsNum
if r>0:
lcdclear()
lcdprint("SMS Received")
setCursor(0,1)
lcdprint("Press Button B")
print "AT+CMGR="+smsNum+"\r"
time.sleep(2)
return str(smsNum)
else:
return 0
def attendCall():
print "Attend call"
Serial.write("ATA\r")
data=""
data=Serial.read(10)
l=data.find("OK")
if l>=0:
lcdclear()
lcdprint("Call attended")
time.sleep(2)
flag=-1;
while flag<0:
data=Serial.read(12);
print data
flag=data.find("NO CARRIER")
#flag=data.find("BUSY")
print flag
lcdclear()
lcdprint("Call Ended")
time.sleep(1)
lcdclear()
def readSMS(index):
print index
Serial.write("AT+CMGR="+index+"\r")
data=""
data=Serial.read(200)
print data
r=data.find("OK")
if r>=0:
r1=data.find("\"\r\n")
msg=""
msg=data[r1+3:r-4]
lcdclear()
lcdprint(msg)
print msg
time.sleep(5)
lcdclear();
smsFlag=0
print "Receive SMS"
def getChar(Key, ind, maxInd):
ch=0
ch=ind
lcdcmd(0x0e)
Char=''
count=0
global msg
global x
global y
while count<20:
key=keypad()
print key
if key== Key:
setCursor(x,y)
Char=alpha[ch]
lcdwrite(ord(Char))
ch=ch+1
if ch>maxInd:
ch=ind
count=0
count=count+1
time.sleep(0.1)
msg+=Char
x=x+1
if x>15:
x=0
y=1
lcdcmd(0x0f)
def alphaKeypad():
lcdclear()
setCursor(x,y)
lcdcmd(0x0f)
msg=""
while 1:
key=0
count=0
key=keypad()
if key == '1':
ind=0
maxInd=6
Key='1'
getChar(Key, ind, maxInd)
elif key == '2':
ind=7
maxInd=10
Key='2'
getChar(Key, ind, maxInd)
elif key == '3':
ind=11
maxInd=14
Key='3'
getChar(Key, ind, maxInd)
elif key == '4':
ind=15
maxInd=18
Key='4'
getChar(Key, ind, maxInd)
elif key == '5':
ind=19
maxInd=22
Key='5'
getChar(Key, ind, maxInd)
elif key == '6':
ind=23
maxInd=26
Key='6'
getChar(Key, ind, maxInd)
elif key == '7':
ind=27
maxInd=31
Key='7'
getChar(Key, ind, maxInd)
elif key == '8':
ind=32
maxInd=35
Key='8'
getChar(Key, ind, maxInd)
elif key == '9':
ind=36
maxInd=40
Key='9'
getChar(Key, ind, maxInd)
elif key == '0':
ind=41
maxInd=42
Key='0'
getChar(Key, ind, maxInd)
elif key == '*':
ind=43
maxInd=43
Key='*'
getChar(Key, ind, maxInd)
elif key == '#':
ind=44
maxInd=44
Key='#'
getChar(Key, ind, maxInd)
elif key== 'D':
return
def sendSMS():
print"Sending sms"
lcdclear()
lcdprint("Enter Number:")
setCursor(0,1)
time.sleep(2)
moNum=""
while 1:
key=0;
key=keypad()
#print key
if key>0:
if key == 'A' or key== 'B' or key== 'C':
print key
return
elif key == 'D':
print key
print moNum
Serial.write("AT+CMGF=1\r")
time.sleep(1)
Serial.write("AT+CMGS=\"+91"+moNum+"\"\r")
time.sleep(2)
data=""
data=Serial.read(60)
print data
alphaKeypad()
print msg
lcdclear()
lcdprint("Sending.....")
Serial.write(msg)
time.sleep(1)
Serial.write("\x1A")
while 1:
data=""
data=Serial.read(40)
print data
l=data.find("+CMGS:")
if l>=0:
lcdclear()
lcdprint("SMS Sent.")
time.sleep(2)
return;
l=data.find("Error")
if l>=0:
lcdclear()
lcdprint("Error")
time.sleep(1)
return
else:
print key
moNum+=key
lcdwrite(ord(key))
time.sleep(0.5)
def call():
print "Call"
n=0
moNum=""
lcdclear()
lcdprint("Enter Number:")
setCursor(0,1)
time.sleep(2)
while 1:
key=0;
key=keypad()
#print key
if key>0:
if key == 'A' or key== 'B' or key== 'D':
print key
return
elif key == 'C':
print key
print moNum
Serial.write("ATD+91"+moNum+";\r")
data=""
time.sleep(2)
data=Serial.read(30)
l=data.find("OK")
if l>=0:
lcdclear()
lcdprint("Calling.....")
setCursor(0,1)
lcdprint("+91"+moNum)
time.sleep(30)
lcdclear()
return
#l=data.find("Error")
#if l>=0:
else:
lcdclear()
lcdprint("Error")
time.sleep(1)
return
else:
print key
moNum+=key
lcdwrite(ord(key))
n=n+1
time.sleep(0.5)
begin()
lcdcmd(0x01)
lcdprint(" Mobile Phone ")
lcdcmd(0xc0)
lcdprint(" Using RPI ")
time.sleep(3)
lcdcmd(0x01)
lcdprint("Circuit Digest")
lcdcmd(0xc0)
lcdprint("Welcomes you")
time.sleep(3)
gsmInit()
smsFlag=0
index=""
while 1:
key=0
key=keypad()
print key
if key == 'A':
attendCall()
elif key == 'B':
readSMS(index)
smsFlag=0
elif key == 'C':
call()
elif key == 'D':
sendSMS()
data=""
Serial.flush()
data=Serial.read(150)
print data
l=data.find("RING")
if l>=0:
callstr=data
receiveCall(data)
l=data.find("\"SM\"")
if l>=0:
smsstr=data
smsIndex=""
(smsIndex)=receiveSMS(smsstr)
print smsIndex
if smsIndex>0:
smsFlag=1
index=smsIndex
if smsFlag == 1:
lcdclear()
lcdprint("New Message")
time.sleep(1)
setCursor(0,0)
lcdprint("C--> Call <--A");
setCursor(0,1);
lcdprint("D--> SMS <--B")
Here are some examples of how GSM technology can be put to use.
Automation and Safety via Smart GSM Technology
Nowadays, we can't live without our GSM mobile terminal. The Mobile phone terminal is essentially an extension of ourselves, allowing us to connect with the world in the same way our wallet/purse, keys, or watch does. Many people like not having to worry about being unavailable or who they can call at any given moment.
It's clear from the name that this Project relies on the SMS transmission capabilities of GSM networks. The ability to send and receive text messages is widely utilized to provide access to equipment and facilitate home security breach management. There are two proposed subsystems in the system. Controlling appliances in one's house from afar is made possible by the appliance control subsystem, while the security alert subsystem provides automatic security monitoring.
The system can send consumers instructions via SMS from a designated phone number to adjust the home appliance's state as needed. An automatic SMS can be generated by the system upon detection of an intrusion, warning the user of a potential threat to their data.
The advent of GSM technology will make global, instantaneous, and universal communication possible. GSM's functional architecture employs intelligent networking principles as the first step toward a genuinely personal communication system with sufficient standards to ensure interoperability.
Medical Uses for GSM-Based Systems
Here are two examples of similar situations to think about.
The patient has sustained a life-threatening injury or illness and requires emergency medical attention. A mobile phone is the only thing he (or his companion) has.
After being released from the hospital, the patient plans to rest at home but is reminded that he must return for routine exams. A mobile phone and perhaps some health monitoring or other medical sensor gadgets may be in his possession.
The only way to solve either problem is via a mobile communication system. In other words, the above scenarios are easily manageable with today's communication technology because all that needs to be done is send the patient's information across a network and have it processed at the receiving end, which may be a hospital or the doctor's office.
In the first scenario, the doctor keeps tabs on the patient's information and returns the instructions to him so he can take whatever precautions before getting to the hospital. In the second scenario, the doctor keeps tabs on the patient's test results and, if necessary, proceeds with treatment.
Telemedicine services are the driving force behind this entire operation. The telemedicine system has three different applications.
Video conferencing lets patients in one location have face-to-face contact with their doctors and nurses, speeding up the healing process.
With the help of sensors that constantly report on a patient's condition and direct medical staff on how to proceed with treatment.
By sending the gathered health information for further review and analysis.
A wireless method of communication is used for the three options mentioned above. When providing healthcare, it is necessary to have many data retrieval mechanisms in place. These can be online medical databases or hosts with equipment that aid recovery and health monitoring. Broadband networks, medium-throughput media, and narrowband GSM access are all viable possibilities.
There are several benefits to using GSM technology in a telemedicine setup.
Cost savings and widespread availability of GSM receivers (including cell phones and modems)
It can transfer data quickly.
Typical Telemedical Infrastructure
The four components that make up a standard telemedicine system are as follows:
The Patient Unit: It takes data from the patient, either in its original analog form or after being converted to digital format, and then manages the data stream before sending it. It is made up of several different types of medical sensors, such as those used to track heart rate, blood pressure, body temperature, spirometry, etc., each of which generates an electrical signal that is sent to a processor or controller for analysis before being transmitted over a wireless network.
Communication Network: As such, it is employed for both data transmission and security. Networks, mobile stations, and base stations are all components of the Global System for Mobile Communication (GSM) system. The mobile station, also known as the mobile phone or primary mobile access point, is the device responsible for connecting mobile devices to the global system for mobile communications (GSM) network.
Receiving/Server Side: This is a healthcare system with a GSM modem installed to receive, decode, and forward signals to the presenting device.
Presentation Unit: This is the brains of the operation. This processor saves the data in a standard format for later retrieval and analysis by doctors and from which they can send text messages to the client side if necessary.
To demonstrate the fundamentals of telemedicine, a rudimentary model will suffice. It has a sender and a receiver, both of which are separate components. The sensor input is transmitted by the transmitter and received by the receiver unit for processing.
See below for a simplified telemedicine system to track a patient's heart rate and apply the results as needed.
The data collected by the heartbeat detector (a light-emitting device whose light is modified as it flows through human blood) is transformed into electrical pulses at the transmitter unit. When the Microcontroller picks up on these pulses, it calculates the heart rate and communicates that information and other data collected to the medical team via a Gsm network. An IC called a Max 232 connects the Microcontroller to the GSM modem.
The GSM modem at the receiving end grabs the information and passes it to the Microcontroller. The Microcontroller then performs an analysis using the input from the Personal computer and displays the outcome on the LCD. Medical professionals can keep tabs on the patient and begin the necessary treatment after reviewing the results on the screen.
The following are some real-world applications for GSM technology.
AT&T Health GlowCaps
These plain pill bottles serve as a gentle prompt to the patient to take their prescribed medications. It uses GSM technology to contact the patient on their mobile phone at the specified pill-taking time, at which point the cap will light up, the buzzer will sound, and the patient will be reminded to take their medication. Each time a bottle is uncorked, it is documented.
Ultrasound technology
With the help of a portable ultrasound transducer that connects to a smartphone, it is possible to send ultrasound images captured with a handheld device to a distant location using a global system for mobile communications (GSM).
A Continuous Glucose Monitor (CGM)
The patient's blood sugar levels can be tracked and reported to the doctor. A sensor is implanted under the skin and monitors blood glucose levels, sending the data to a receiver (a mobile phone) at regular intervals.
As part of this guide, we analyzed GSM's architecture and learned how it operates in practice. We wrote a Python program to turn our Raspberry Pi 4 into a fully functional mobile phone. No technical difficulties were encountered as we watched text and phone calls travel between the raspberry pi and our mobile phone. You should feel confident in your ability to apply the ideas and understand the circuits of GSM now. One way to up the difficulty level of this Project is to try to make a live video call using the raspberry pi 4 mobile. Next, we'll look at connecting the pcf8591 ADC/DAC analog-digital converter module to a Raspberry Pi.
A teacher is the one who helps children to develop skills to learn and exploring the world. If we want our children to be skilled person, we need to take care of their education. Schools are not enough for them, homeschooling is a great idea where parents can teach their child with better attention. Parents must collaborate with teacher for better result. A teacher is the one who helps children to develop skills to learn and exploring the world. If we want our children to be skilled person, we need to take care of their education. Schools are not enough for them, homeschooling is a great idea where parents can teach their child with better attention. Parents must collaborate with teacher for better result.
eLearning News for Pasco Parents is a blog that provides information on educational topics and trends. If you are a parent in Pasco County, Florida, this blog is the perfect place to find out more about the latest developments in the world of education. . How to Get your Child on the School BusPasco County Public Schools has created a video which provides information on how to get your child on the school bus. If you find yourself stuck at home with a sick child, please watch this video to learn the best way for you to get him or her to school.
Learning Continuity Planning is a process that is used to assess the needs of the organization and plan for future learning. This process can be used to identify gaps in knowledge, skills and abilities of employees, which can later be addressed through training or other means.
This process can also help organizations to stay competitive by providing continuous learning opportunities for their employees.
A Learning Continuity Plan is a workbook that you can use to map out your training. It includes all the learning materials, tools and assessments, so that you know what learners will need for which courses and what they have already completed.
Continuing Education OutcomesAn outcome is a measurable, quantifiable result that a learner achieves which helps them progress towards achieving their goal.
Pasco's Plan is a revitalization strategy for the Pasco Region, a region that has been plagued by economic uncertainty and unemployment. The planning document is a blueprint for the future of Pasco, defining workforce development, transportation and housing as key areas.The Planning Brochure was approved by the City Council on December 4th, 2017. The plan seeks to address the need for economic stability in Pasco through diversification and improvement of its industrial sector and supporting industries, support for entrepreneurship and small business growth, increased engagement with local governments to develop a regional sustainability strategy that supports agriculture, natural resources management and tourism industries Powered by a regional push towards urban sustainability, the report identifies three key actions to further the region’s sustainability:Establish a regional coalition focused on urban sustainabilityIncrease public awareness of local issues and mobilize support for sustainable policies in each metro areaDevelop educational tools for increasing awareness and action around local sustainability issues in each metro areaThis project is a collaboration among the Metropolitan Planning Organizations of Louisville, Ky.; Phoenix, Ariz.; and Portland, Ore. These cities are selected as they represent a cross-section of metropolitan areas in the United States with diverse livability characteristics.
Pasco County, Florida is a county located in the U.S. state of Florida, and it has a population of about 710,000 people. Pasco County is home to some of the most popular tourist attractions in the country such as Busch Gardens Tampa Bay and Adventure Island. It also has some of the best schools in the state with many colleges and universities such as Pasco-Hernando State College, University of South Florida Polytechnic, Hernando State College, and Hillsborough Community College.
Pasco County offers many different services for its citizens including education services, public safety services such as firefighting and police protection, public works services that provide water treatment and wastewater management systems to protect our environment.
The Pasco County government provides access to a range of information through their website myPascoConnect which includes information on how to register your dog or cat for rabies shots or where you can find recycling centers near you. The Hillsborough County government provides access to a range of information through their website myHillsborough. This includes information on how to register your pet for a rabies shot or where you can find recycling centers near you.
Students are often faced with the difficult task of balancing their education and their personal lives, which can lead to a lack of motivation, stress, and anxiety.
There are many different ways to learn new skills and improve existing ones. The key is finding what works best for you. There is no one-size-fits-all solution when it comes to learning tools or routines. As such, students should experiment with different tools and routines until they find the right fit for them.
There are many different online tools that can help students learn new skills or improve existing ones. For example, Khan Academy provides free videos on a variety of subjects that students can watch at their own pace in order to improve their skills in subjects like math, science, economics and more. Coursera also offers courses on various topics that range from programming languages like Python or JavaScript to psychology to history.
Students should try out various learning routines until they find one that feels good. Study Skills: Students should learn to set aside time for studying and to study regularly.
| Where To Buy? | ||||
|---|---|---|---|---|
| No. | Components | Distributor | Link To Buy | |
| 1 | Breadboard | Amazon | Buy Now | |
| 2 | Jumper Wires | Amazon | Buy Now | |
| 3 | LCD 16x2 | Amazon | Buy Now | |
| 4 | nRF24L01 | Amazon | Buy Now | |
| 5 | Arduino Uno | Amazon | Buy Now | |
| 6 | Raspberry Pi 4 | Amazon | Buy Now | |
We're glad you could join us for another lesson in our series on programming for the Raspberry Pi 4. The previous chapter covered how to interface the USB barcode scanner with raspberry pi 4. We looked at different types of barcodes and what each stripe represents as well as the different types of barcode scanners available today. We also built a python program for the intelligent shopping cart and now our familiarity with barcodes and scanners and how they function has significantly increased. The benefits and drawbacks of its use were also discussed, but what we're interested in for this article is the transmission of radio frequency signals using the nrf24l01 Module in a raspberry pi 4.
nRF24L01 RF module
Raspberry pi 4
Arduino Uno
Jumper wires
Power supply
16x2 liquid crystal display
Wireless communication systems, such as ESPS266 WiFi modules, are widely used in the design process. Further, the media chosen is determined by the function it will serve. It's no secret that the nRF24L01 is a widely used wireless channel for local area network communication. These modules have a band rate of 250Kbps to 2Mbps and transmit on the 2.4GHz (ISM band), which is permitted in many states and suitable for usage in industrial and healthcare settings. There is also the claim that these modules can communicate at a distance of up to 100 meters with the correct antennae.
This tutorial demonstrates how to set up wireless communication between an Arduino UNO and a Raspberry Pi by utilizing the nRF24L01 - 2.4GHz RF Transceiver module. Raspberry Pi will broadcast data via nRF24L01, and Arduino Board will receive the data and display it on a 16x2 LCD. In addition to its built-in WiFi and Bluetooth Low Energy (BLE) capabilities, the nRF24L01 is also capable of wireless communication via BLE.
Both parts of the tutorial are equally important. In the first, we'll see how to connect the nRF24L01 to an Arduino so that it can function as a receiver, and in the second, we'll do the same thing with a Raspberry Pi can send out signals.
There are many different types of electromagnetic waves. Still, the ones utilized for radar signals and communications fall into roughly 3 kHz to 300 GHz range, known as "radio frequencies."
The term "radio frequency" is more commonly used to refer to electrical than mechanical oscillations. There are, however, examples of mechanical RF systems. Although radio frequency (RF) refers to an oscillation rate, the term "radio frequency" (RF) is sometimes used interchangeably with "radio" to describe the practice of communicating without the need for wires.
Numerous wireless technologies rely on RF fields, including cordless and cell phones, radio and television broadcasting stations, satellite telecommunication networks, Bluetooth communication modules and WiFi, and two-way radios.
External communications include various products like garage doors and microwave ovens, which use radio frequencies. The infrared frequencies of various wireless devices, like TV remote controllers, computer mice, and some wireless computer keyboards, have shorter electromagnetic wavelengths.
The frequency of radio transmission is expressed in hertz (Hz) units, which stand for the count of cycles per second. Radio waves can travel from one thousand hertz (kHz) to several gigahertz (GHz). Microwaves, a form of radio wave, operate at much higher frequencies. Because of this, we can't see radio frequencies (RFs).
The wavelength' of a radio wave is proportional to the square root of the frequency 'f.' The relationship between frequency and wavelength can be expressed in megahertz and meters, respectively.
s = 300/f
At higher frequencies, electromagnetic radiation is manifested as infrared (IR), ultraviolet (UV), visible (Visible), X-ray (XR), and gamma-ray (GJ).
The following are some of the defining features of RF:
Low energy consumption
It has an excellent operational range (three to thirty meters), a data rate of up to two megabits per second, the ability to pass through walls, and can transmit in any direction.
Due to their half-duplex design, the nRF24L01 modules can only send or receive data but not do both. The Module's data transmission and reception are handled by the generic Nordic semi-conductor nRF24L01 IC. The IC uses the simple serial peripheral interface (SPI) protocol for communication, making it compatible with virtually all microcontrollers. Arduino makes things much simpler because there are numerous library resources available. The following table depicts the pin configurations of a typical nRF24L01 module.
The Module is battery efficient, as its operating voltage ranges from 1.9V to 3.6V, and it draws minimal current (only 12mA) during regular operation. Most pins can be connected directly with 5V chipsets like Arduino, even though the voltage rating is 3.3V. Each Module also includes 6 Pipelines, which is a huge time saver. Simply put, each Module can exchange information with up to six others. Therefore, the Module can be used for IoT applications requiring the creation of star or mesh networks. With an extensive network address of 125 unique IDs, we may use 125 such components in a contained space without worrying about them interfering with one another.
Given that the Module supports 125 separate channels, creating a network containing 125 fully available modems at a single location is theoretically possible. Each device can simultaneously interface with up to six others on the same channel.
Transmission with this Module only uses about 12mA of power, less than a single display LED screen. The Module requires a voltage of 1.9V to 3.6V to function. Still, the other pins are 5V logic compatible, allowing us to connect it directly to an Arduino without needing logic-level converters.
Three of these terminals are used for SPI communication and must be hooked up to the SPI pins on the Arduino; however, the SPI pins on different Arduino boards are labelled differently. Connecting the CSN and CE pins to any input pin on the Arduino board toggles between standby and active modes and transmit and command modes for the Module. The last connector is an interrupt pin, which is optional.
The NRF24L01 modules can be found in a wide range of versions. The model with a built-in antenna is the clear frontrunner. This reduces the transmission range of the Module to around 100 meters but allows for a smaller module size.
In the second variant, an SMA connector replaces the onboard antenna, allowing us to use a duck transmitter for enhanced signal strength.
The third variant displayed here also features the duck antenna with an RFX2401C microprocessor with an integrated Power Amplifier and Low-Noise Amplifier). This can increase the NRF24L01's transmission range in open areas by 1000.
The components in the circuit design for linking nRF24L01 to Arduino are few, and the process is straightforward. SPI will be used to link the nRF24l01, and I2C will connect the 16x2 LCD.
Because only the SPI adapter is required to link the Raspberry Pi and the nRF24L01, the corresponding circuit schematic is pretty straightforward.
Python3 will be used for Raspberry Pi's programming. The Arduino platform is not the only one that can use C/C++. However, if you're programming in Python, you can get a library for nRF24l01 that's already been made. Keep in mind that the library and the python program must be in the same folder for the python program to use it. Create a folder to house your applications and library files after you have downloaded and extracted the library. After the necessary libraries have been installed, you can begin coding immediately. Importing libraries like the GPIO library for communicating with the Raspberry Pi's GPIO pins and the time library for using the Pi's clock and date functions are the first steps in writing any program.
import RPi.GPIO as GPIO
import time
import spidev
from lib_nrf24 import NRF24
It would be best if you switched to the "Broadcom SOC channel" for the GPIO setting. Pins are referred to by their "Broadcom SOC channel" numbers, which follow the letters "GPIO" (GPIO01, GPIO02, etc.). The Board Numbers are not these.
GPIO.setmode(GPIO.BCM)
After that, we'll assign a permanent address for the pipe. To send data to Arduino, you'll need to use this address. There will be a hexadecimal representation of the address.
pipes = [[0xE0, 0xE0, 0xF1, 0xF1, 0xE0], [0xF1, 0xF1, 0xF0, 0xF0, 0xE0]]
Start the radio with the CE pin (GPIO08) and the CSN pin (GPIO25).
radio.begin(0, 25)
Change the power levels to minimal, the channel address to 76, the data rate to 1 Mbps, and the payload size to 32 bits.
radio.setPayloadSize(32)
radio.setChannel(0x76)
radio.setDataRate(NRF24.BR_1MBPS)
radio.setPALevel(NRF24.PA_MIN)
Start the data writing process by opening the pipes and displaying some nRF24l01 basics.
radio.openWritingPipe(pipes[0])
radio.printDetails()
Get your message ready to send as a string. Arduino UNO will receive this message.
sendMessage = list("Hi..Arduino UNO")
while len(sendMessage) < 32:
sendMessage.append(0)
Send the string's first character to the stereo and continue doing so until the radio is ready to receive it. In addition, a debug statement detailing the time and date the message was delivered should be printed.
While True:
start = time.time()
radio.write(sendMessage)
print("Sent the message: {}".format(sendMessage))
send
radio.start listening()
A timed-out error message should be printed if the thread is finished and the conduit is closed.
while not radio.available(0):
time.sleep(1/100)
If time.time() - start > 2:
print("Timed out.") # print error message if radio disconnected or not functioning anymore
break
If you want to send another message, turn off the radio and disconnect from the connection for three seconds.
radio.stopListening() # close radio
time.sleep(3) # give a delay of 3 seconds
If you know the fundamentals of Python, you can easily comprehend the Raspberry program. You will find a fully functional Python program at the end of this tutorial.
If you follow the steps below, running the software will be a breeze.
You should keep the Python source code and library files together.
My Sender program file is nrfsend.py, and all the related files are in the same directory.
Access Raspberry Pi's command prompt. Use the cd command to get to the directory containing the python script.
Navigate to the directory, type "sudo python3 your program.py," and hit enter to run the program. In less than a minute, you'll likely see nRf24's essentials laid out, and the broadcaster will begin broadcasting its bulletins at three-second intervals. Once the send is complete, the debug message will appear.
The Arduino UNO will now display the same code as the receiver.
The Arduino UNO can be programmed in a manner not dissimilar to that of the Raspberry Pi. Our procedures will be very similar; however, we'll use a different language for programming and other processes. The procedure will incorporate the nRF24l01 readout. Download the nRF24l01 Arduino library from GitHub. To get started, make sure all required libraries are installed. We're using a 16x2 I2C LCD, so we need to include the Wire.h library; the nRF24l01 communicates via SPI, so we also need the SPI library.
#include<SPI.h>
#include <Wire.h>
Don't forget to add the RF24 and LCD libraries so you may use them.
#include<RF24.h>
#include <LiquidCrystal_I2C.h>
Put the LCD's I2C address—27 in this case, as it's a 16x2 display—into the appropriate function.
LiquidCrystal_I2C lcd(0x27, 16, 2);
Pin 9 serves as the RF24's Common Emitter, and pin 10 serves as its Common Source Negative.
RF24 radio(9, 10) ;
Turn the radio on and tune in to channel 76. In addition, open the pipe for reading by setting the address to that of the Raspberry Pi.
radio.begin();
radio.setPALevel(RF24_PA_MAX) ;
radio.setChannel(0x76) ;
const uint64_t pipe = 0xE0E0F1F1E0LL ;
radio.openReadingPipe(1, pipe) ;
Start the I2C data transfer and initialize the LCD screen.
Wire.begin();
lcd.begin();
lcd.home();
lcd.print("Ready to Receive");
Turn on the radio's receiver and enter a message length of 32.
radio.startListening() ;
char receivedMessage[32] = {0}
The message will be read and saved immediately if a radio is connected. Display the message on the screen and send it to the serial monitor till the following message is received. Put the radio on hold while you tune in, then try again later. Right this way, in ten microseconds.
if (radio.available()) {
radio.read(receivedMessage, sizeof(receivedMessage));
Serial.println(receivedMessage) ;
Serial.println("Turning off the radio.") ;
radio.stopListening() ;
String stringMessage(receivedMessage) ;
lcd.clear();
delay(1000);
lcd.print(stringMessage);
}
Copy and paste the code below into your server and allow time for the response to arrive.
import RPi.GPIO as GPIO # import gpio
import time #import time library
import spidev
from lib_nrf24 import NRF24 #import NRF24 library
GPIO.setmode(GPIO.BCM) # set the gpio mode
# set the pipe address. This address should be entered on the receiver to
pipes = [[0xE0, 0xE0, 0xF1, 0xF1, 0xE0], [0xF1, 0xF1, 0xF0, 0xF0, 0xE0]]
radio = NRF24(GPIO, spidev.SpiDev()) # use the gpio pins
radio.begin(0, 25) # start the radio and set the ce,csn pin ce= GPIO08, csn= GPIO25
radio.setPayloadSize(32) #set the payload size as 32 bytes
radio.setChannel(0x76) # set the channel as 76 hex
radio.setDataRate(NRF24.BR_1MBPS) # set radio data rate
radio.setPALevel(NRF24.PA_MIN) # set PA level
radio.setAutoAck(True) # set acknowledgement as true
radio.enableDynamicPayloads()
radio.enableAckPayload()
radio.openWritingPipe(pipes[0]) # open the defined pipe for writing
radio.printDetails() # print basic detals of radio
sendMessage = list("Hi..Arduino UNO") #the message to be sent
while len(sendMessage) < 32:
sendMessage.append(0)
While True:
start = time.time() #start the time for checking delivery time
radio.write(sendMessage) # just write the message to radio
print("Sent the message: {}".format(sendMessage)) # print a message after succesfull send
radio.startListening() # Start listening the radio
while not radio.available(0):
time.sleep(1/100)
if time.time() - start > 2:
print("Timed out.") # print error message if the radio disconnected or not functioning anymore
break
radio.stopListening() # close radio
time.sleep(3) # give delay of 3 seconds
#include<SPI.h> // spi library for connecting nrf
#include <Wire.h> // i2c libary fro 16x2 lcd display
#include<RF24.h> // nrf library
#include <LiquidCrystal_I2C.h> // 16x2 lcd display library
LiquidCrystal_I2C lcd(0x27, 16, 2); // i2c address is 0x27
RF24 radio(9, 10) ; // ce, csn pins
void setup(void) {
while (!Serial) ;
Serial.begin(9600) ; // start serial monitor baud rate
Serial.println("Starting.. Setting Up.. Radio on..") ; // debug message
radio.begin(); // start radio at ce csn pin 9 and 10
radio.setPALevel(RF24_PA_MAX) ; // set power level
radio.setChannel(0x76) ; // set chanel at 76
const uint64_t pipe = 0xE0E0F1F1E0LL ; // pipe address same as sender i.e. raspberry pi
radio.openReadingPipe(1, pipe) ; // start reading pipe
radio.enableDynamicPayloads() ;
radio.powerUp() ;
Wire.begin(); //start i2c address
lcd.begin(); // start lcd
lcd.home();
lcd.print("Ready to Receive"); // print starting message on lcd
delay(2000);
lcd.clear();
}
void loop(void) {
radio.startListening() ; // start listening forever
char receivedMessage[32] = {0} ; // set incmng message for 32 bytes
if (radio.available()) { // check if message is coming
radio.read(receivedMessage, sizeof(receivedMessage)); // read the message and save
Serial.println(receivedMessage) ; // print message on serial monitor
Serial.println("Turning off the radio.") ; // print message on serial monitor
radio.stopListening() ; // stop listening radio
String stringMessage(receivedMessage) ; // change char to string
lcd.clear(); // clear screen for new message
delay(1000); // delay of 1 second
lcd.print(stringMessage); // print received mesage
}
delay(10);
}
The RF module's performance will be affected by the same factors as any other RF component. For instance, a transmitter's output power can be increased to extend the range of a transmission. However, this will cause a greater consumption of electricity by the transmitters (TX) device, reducing the useful life of battery-operated gadgets. Increasing the system's transmit power also makes it more vulnerable to interference from a second RF source.
Similarly, boosting the receiver's sensitivity increases the usable communication range but increases the risk of an error brought on by interference from other RF equipment. Matching antennas on both ends of a communication link can potentially boost the overall system's performance.
Finally, the regarded remote distance of any given system is typically measured in an open-air line-of-sight outline without any interference; nevertheless, problems such as floors, walls, and dense structures will frequently grasp the radio wave signals; thus, the actual operational distance will typically be less than specified.
The most common uses of radio frequency communication are in the areas of wireless data and voice transfer, home automation, and remote control, as well as in the industrial and commercial sectors.
RF-controlled switches can be used in home automation applications as an alternative to traditional switches. An RF remote allows one to operate lights and other electronics without leaving their current location. Those with mobility issues will benefit the most from this app. RF communication is helpful in industrial settings for directing autonomous robots and motorized vehicles. These robot vehicles are often employed in hazardous tasks humans cannot undertake. A data transmission unit is required to direct the motion of the robotic vehicles.
Multiple factors make radio frequency (RF) transmission preferable to infrared (IR) (infrared). The more extended range of RF signals makes them ideal for long-distance communications. Unlike radio frequency (RF), which can go across obstacles, infrared (IR) generally requires a clear path from transmitter to receiver. The reliability of RF transmission is far greater than that of infrared remote communications. While radio frequency (RF) communications require other IR-emitting devices that can disrupt a precise frequency range, infrared (IR) communications.
These are some of RF's drawbacks.
Preschoolers, expectant mothers, the elderly, those with pacemakers, little birds, flora, wildlife, insects, etc., are all negatively impacted by unregulated RF radiation.
More lightning has been seen in nearby cellular towers that use radio frequency than in other areas.
Some fruit crops in the vicinity of RF towers are also negatively impacted.
Because RF waves are accessible in both line-of-sight (LOS) and non-LOS zones of the transmitter, hackers can easily break into the system and decode sensitive personal or government data.
This problem can be avoided by employing highly protected methods like AES, WEP, WPA, etc., while transmitting data over radio frequency waves. Spread spectrum and frequency hopping modulation methods can also be applied to RF signals to prevent such eavesdropping.
This concludes the comprehensive instruction on wireless communication between a Raspberry Pi and an Arduino UNO via nRf24l01 modules. The 16 * 2 liquid crystal display will show the message. Pipe addresses are crucial on the Arduino UNO and the Raspberry Pi 4. In the following tutorial, we will learn how to Call and Text using Raspberry Pi and GSM Module in pi 4.
Hello friends, I hope you all are doing great. Today, we are going to start a new section in our Raspberry Pi Programming Course. In this section-VIII, we will implement advance protocols in the RPi4 board. Today's our first lecture in this section and we are going to interface a USB Bar Code Scanner with Raspberry Pi 4.
If you have visited any big grocery store, you must have seen, it's quite important as well as difficult to maintain the products in stock at all times. To ease the job, barcode technology is used because it can easily maintain an organized database of your items, costs, and inventory levels in one convenient location. Price changes can be implemented whenever you desire without requiring new labels for previously packaged goods. You can tell exactly when your supply of a particular item is getting low, so you may place a new purchase before you run out. Since the barcode system is so precise, you may assume that any missing (and seemingly unsold) items have been stolen.
Here's the video demonstration of this barcode tutorial:
So, let's get started with the implementation of a barcode scanner with Raspberry Pi 4:
In this post, you'll learn how to read the Barcode scanner's output in the Serial interface of Raspberry Pi 4 and display the scanned code on the 16x2 LCD. When a User reviews an item's code, the LCD will update to reflect the new total number of items in the shopping basket. This configuration allows us to create an intelligent cart with an integrated billing system.
Here's the list of components, used in designing today's project:
Barcode Scanner can read a wide range of linear barcodes. Barcode
scanners are commonly utilized in retail settings like supermarkets,
grocery stores, restaurants, boutiques, warehouse inventory,
invoices for bookkeeping and other retail establishments.
Intelligent shopping carts now use barcode scanners to quickly and
accurately identify products.
Connecting your handheld barcode scanner to a computer is as simple as plugging it into a USB port. Barcode scanners can typically decode at speeds of up to 300 scans/second. Additionally, they can easily read a wide range of scratchy, blurry barcodes.
Serial output through USB is provided in either H.I.D. mode or RS232 mode, depending on the device's configuration. Users can change the Baud rate from 9600 to 115200 and modify the Suffix by adding a C.R., L.F., CR+LF, or no ending characters. And you may set it to read in either Trigger Mode or Continuous Mode. Scanning the included settings sheet's Barcode will also restore the machine to its factory defaults.
As we discussed above, the black & white bars are actually representing a numeric digit. We are hiding the numeric digit in black & white bars because it's difficult for computers to recognize decimal numbers but reading a simple bar is quite easy. The below figure shows the respective bars for numeric digits 0-9:
Looking at a barcode, it might be difficult to determine, where one set of numbers stops and another starts. But in reality, it's pretty easy. There are precisely seven units of horizontal space in each letter. So, in order to get the numeric digit "1", the bar code(starting from left) has two white lines, two black lines, two white lines, and finally one black line, as shown in the above figure.
The barcode printing on the consumer goods has a universal representation i.e. a series of vertical stripes and the numeric code imprinted below, so that, the Barcode can be manually keyed in, if it is incorrectly printed or scratched in the store. Two-dimensional barcodes are also used on some items i.e. postal stamps, as shown in the below figure:
Let's pretend that barcodes are specific on-off binary sequences, with every black stripe representing a one and every white stripe representing a zero. (We've seen that actual barcodes are more complex than this, but for now, simplicity is in order.)
Some scanners use a single photosensitive cell that reads the barcode pixel by pixel as you slide the sensor head over the item (or the product across the reader). The complete Code is detected in a single pass, thanks to a row of photoelectric cells in more complex scanners.
The following are examples of well-known barcode types:
The European Item Numbering Scheme (EAN) is a specialized version of the Uniform Product Code (U.P.C.) for items with a thirteen-digit identifier. There are 13 digits in an EAN13 barcode.
The retail sector heavily uses UPC-A barcodes based on the U.P.C. The Universal Product Code, Extended (UPC-A), comprises 12 digits.
(EAN -8) uses a set of numbers superseding the U.P.C. EAN-8 for compact shipments; these numbers include eight digits.
Like code 128's character set C, Intermingled 2 of 5 (I.T.F.) is an arithmetic barcode used to encode pairs of integers in a space-efficient manner.
The Code 39 Q.R. code is the most straightforward of all the alphanumeric barcodes because it performs its character verification.
Code 128 is a high-density, efficient symbology for encoding alphanumeric data. The checksum digit is incorporated into the symbology, and the Barcode's integrity can be checked by comparing the checksum with the original data or by comparing the Barcode's bytes to the original data's parity.
Since Code 128 is widely utilized for its ability to hold alphanumeric data of a fixed length, we've chosen it to employ in our project.
Pen-type Barcode
This scanner is widely used in retail stores as its cordless. A photodiode and L.E.D. are integrated into its tip. When light is shone on a barcode, its dark bars soak up the rays. In addition, the photodiode's output is reflected in the white areas. Because of this, the scanner can read the generated output waveform. They guarantee low costs and long service life. More specifically, the scanner has to maintain a fixed angle as it moves across the barcodes at a fixed rate. The user may have to spend some time at the gym to get good at this.
Laser-type Barcode
They follow the same principle as traditional pen readers. They use a laser beam as the light source and a revolving prism to detect it. Therefore, they are effective even at a distance of two feet. This allows them to be surface-mounted, eliminating the need for handshakes. Compared to traditional pen-style scanners, these are far superior due to their speed and accuracy.
Light-Emitting Diode Scanner
The ambient light that the Barcode emits is what is measured. The information is translated into a voltage pattern, which is then read by an L.E.D. scanner. Unlike other barcode scanners, this one doesn't come with a light source. Although the C.C.D. systems are pricey, they are more adaptable and accurate than alternatives. They're commonly found in stores.
Camera barcode reader
The two-dimensional Barcode is usually scanned using a barcode scanner with a two-dimensional camera. The camera must be set to auto-focus and maintained at a fixed distance. Multiple small lights are placed to form the camera. The barcodes will be photographed digitally and uploaded to the system.
Imaging barcodes with a cell phone
These days, practically every smartphone has a built-in scanner. Successfully scanning the 2-dimensional Bar code will not necessitate autofocus. These barcodes are unreadable by a regular scanner.
The Barcode detected by the barcode reader will be displayed on a 16x2 LCD screen connected to the Raspberry Pi 4.
The image below illustrates the circuit diagram of Raspberry Pi 4 with an LCD display and barcode scanner.
The Barcode scanner is connected via USB to Raspberry Pi 4, while the LCD is connected to the SPI pins of RPi4. The SPI pinout is as follows:
Here's the circuit diagram of the LCD 16x2 with RPi4:
Here's our hardware setup and as you can see, we have interfaced both LCD and barcode scanner with the Raspberry Pi 4. We also have a sheet of barcodes to scan:
To begin, we need to turn on I2C on the Raspberry Pi. Here is the command to enter in the terminal:
sudo raspi-config
Now, use the down arrow key to access the Interfacing menu, and from there, select the P5 option, which is the I2C Enable/Disable menu item.
Once that's done, it'll inquire whether or not "you want the A.R.M. interface to be enabled." If you want to see "The ARM I2C adapter is enabled," select "Yes>." Select "ok" and then "Complete" to confirm your selections.
To begin working on the Liquid crystal display, you must first verify its I2C address in the Python console.
sudo i2cdetect -y 1
The attached I2C device has address 27, as shown above.
This came together with my barcode scanner. This card will allow us to quickly and easily alter the device's default settings and change the Data rate, Trigger mode, and more.
Make sure the method of data transmission is USB transmission before we begin programming. The reading mode should be set to Triggering, and the Suffix should be C.R.*. The end of a data set information is always signaled by an enter command when a carriage return is used.
Now, access the Pi's command prompt and type pip install RPI LCD to get the software package downloaded and set up. My laptop and Raspberry Pi share the same wifi network; thus, I can control it from here using a V.N.C. viewer. In addition, I used THONNY and Python 3.7.3 to write the Code.
Since we'll be using Delay to show the material on the LCD, we're starting the Program by importing the Sleep object from time. Then, the RPI LCD object, used for integrating the 16 x 2 display, will be imported.
from time import sleep
from rpi_lcd import LCD
The number of objects scanned up until the loop's execution is kept in an item count variable. At first, it is set to 0 so that no invalid values are stored. For the same reason, the scanned Barcode will be saved in a variable called score, which will initially be empty.
item_count=0
scode=""
LCD.text("Scan the Code... ", 1)
As long as the while loop is active, scanning will continue indefinitely unless the controller is reset. Terminal input is required for this loop's input() function, and the resulting String will be saved in the variable scope. Then, we'll get it shown on an LCD screen:
While 1:
scode= str(input())
LCD.text("Scanned Barcode is", 1)
LCD.text(code,2)
sleep(2)
LCD.text(" Item Added", 1)
sleep(2)
item_count=item_count+1
IC=str(item_count)
LCD.text(" Total Item = ",1)
LCD.text(IC,2)
sleep(1)
The initial value of the item count was 0; however, it will be increased while the loop is executed. The item count is currently set to 1. We'll use typecasting to change the item count value from an integer to a string so that it can be shown on the LCD screen through the LCD.text() function.
Viewing the accompanying illustrations may help clarify matters. After two seconds, the LCD will show the total number of items scanned rather than the scanned Barcode itself (which will remain on the screen for two seconds).
from time import sleep
from rpi_lcd import LCD
LCD = LCD()
item_count=0
scode=""
LCD.text("Scan the Code... ", 1)
while 1:
scode= str(input())
LCD.text("Scanned Barcode is", 1)
LCD.text(code,2)
sleep(2) #Delay of 2 seconds
LCD.text(" Item Added", 1)
sleep(2)
item_count=item_count+1
IC=str(item_count)
LCD.text(" Total Item = ",1)
LCD.text(IC,2)
sleep(1)
The following illustration depicts the wiring for connecting a barcode reader, thermal printers, and Liquid crystal display to a Raspberry Pi 4. The following table shows the relationships between these terms for your convenience.
Now that we have all the parts hooked up, we can begin writing the Program for the intelligent cart. Before moving further, let's review the ideas we've covered in our prior assignments. I am compiling a summary of the essential takeaways from the preceding part.
import spread
from time import sleep
from RPLCD.i2c import CharLCD
LCD = CharLCD('PCF8574', 0x27)
from escpos.printer import Serial
from DateTime import DateTime
now = DateTime.now()
dt_string = now.strftime("%b/%d/%Y %H:%M:%S")
lcd.cursor_pos = (0, 0)
LCD.write_string("Initialising...")
#locating the spreadsheet JSON file
GC = spread.service_account(filename='/home/pi/Ali Proj/Proj 4 Shopping Cart with Thermal Printer/Shopping Cart on 20_4 LCD/shop-data-thermal-585dc7bffa1f.json')
#sheet name is to be passed
sh = GC.open("Shop Data for Thermal")
worksheet=sh.get_worksheet(0)
The preceding Code includes imports for all required libraries, including spread for the Google Sheets Application programming interface, time for wait or rest functions, RPLCD for 20X4 Liquid crystal display, escapes for serially controlling the Heated Printer, and date and Time for retrieving the current date.
Using my Google account, I made a spreadsheet titled "Shop Data for Thermal." Please create your own and give it any name you wish. Please see the G spread docs for information on setting up your Google Spreadsheet and JSON for your Google service account.
Next, we'll launch Sheet1 by invoking get worksheet(0) and loading it into the sh editor.
""" 9600 Baud, 8N1, Flow Control Enabled """
p = Serial(devfile='/dev/serial0',
baudrate=9600,
bytesize=8,
parity='N',
stopbits=1,
timeout=1.00,
dsrdtr=True)
This Code will be used to set up and initialize the serial port based on the parameters provided.
count=0
item_cost=0
totalCost=0
SNo=0
scode=""
qty=1
scodePrev=0
item_name=""
entryF=[]
p.set(
align="center",
font="a",
width=1,
height=1,
)
The necessary variables will now be initialized to " " or " 0 " to prevent any invalid data from being stored in them. In addition, the set() function will be used to establish the thermal printer's default printing settings.
def print_receipt():
p.text("\n")
p.set(
align="center",
font="a",
width=1,
height=1,
)
#Printing the image
p.image("/home/pi/Ali Proj/Proj 3 Interfacing thermal printer with pi/CD_new_Logo_black.png",impl="bitImageColumn")
#printing the initial data
p.set(width=2,
height=2,
align="center",)
p.text(" ===============\n")
p.text("Tax Invoice\n")
p.text(" ===============\n")
p.set(width=1,
height=1,
align="left",)
p.text("CIRCUIT DIGEST\n")
p.text("AIRPORT ROAD\n")
p.text("LOCATION : JAIPUR\n")
p.text("TEL : 0141222585\n")
p.text("GSTIN : 08AAMFT88558855\n")
p.text("Bill No. : \n\n")
p.text("DATE : ")
p.text(dt_string)
p.text("\n")
p.text("CASHIER : \n")
p.text(" ===========================\n")
p.text("S.No ITEM QTY PRICE\n")
p.text(" ------------------------------\n")
print(text_F)
p.text(text_F)
p.text(" -------------------------------\n")
p.set(
# underline=0,
align="right",
)
p.text(" SUBTOTAL: ")
p.text(totalCostS)
p.text("\n")
p.text(" DISCOUNT: 0\n")
p.text(" VAT @ 0%: 0\n")
p.text(" ===========================\n")
p.set(align="center",
)
p.text(" BILL TOTAL: ")
p.text(totalCostS)
p.text("\n")
p.text(" --------------------------\n")
p.text("THANK YOU\n")
p.set(width=2,
height=2,
align="center",)
p.text(" ===============\n")
p.text("Please scan\nto Pay\n")
p.text(" ===============\n")
p.set(
align="center",
font="a",
width=1,
height=1,
density=2,
invert=0,
smooth=False,
flip=False,
)
p.qr("9509957951@ybl",native=True,size=12)
p.text("\n")
p.barcode('123456', 'CODE39')
#if your printer has paper cutting facility, then you can use this function
p.cut()
print("printing done")
With the Code above, we can quickly generate a method to output the total due. The invoice's format is also determined in the same procedure. A '123456' barcode can be printed using the p.barcode() method.
Suppose the detected Barcode does not match the database sheet. In that case, a message will be displayed on the terminal's Liquid crystal display and in the terminal's memory reading "Unknown Barcode" or "Item Not Registered," respectively, using the try/except logic. You can view this under the following line of Code.
lcd.cursor_pos = (0, 0)
LCD.write_string('Please Scan...')
while 1:
try:
scode=input("Scan the barcode")
if scode=="8906128542687": #Bill Printing Barcode pasted on the Thermal Printer
print("done shopping ")
LCD.clear()
print(*entryF)
print("in string")
print(len(entryF))
text_F=" "
for i in range(0,len(entryF)):
text_F=text_F+entryF[i]
i=i+1
lcd.cursor_pos = (0, 0)
lcd.write_string("Thanks for Shopping")
lcd.cursor_pos = (1, 7)
lcd.write_string("With Us")
lcd.cursor_pos = (3, 0)
lcd.write_string("Printing Invoice...")
print_receipt()
else:
cell=worksheet.find(code)
print("found on R%sC%s"%(cell.row,cell.col))
item_cost = worksheet.cell(cell.row, cell.col+2).value
item_name = worksheet.cell(cell.row, cell.col+1).value
lcd.clear()
SNo=SNo+1
entry = [SNo,item_name,qty,item_cost]
entryS=str(entry)+'\n'
print("New Item ",*entry)
lcd.cursor_pos = (0, 2)
LCD.write_string(str(SNo))
lcd.cursor_pos = (0, 5)
LCD.write_string("Item(s) added")
lcd.cursor_pos = (1, 1)
LCD.write_string(item_name)
lcd.cursor_pos = (2, 5)
LCD.write_string("of Rs.")
lcd.cursor_pos = (2, 11)
LCD.write_string(item_cost)
item_cost=int(item_cost)
totalCost=item_cost+totalCost
lcd.cursor_pos = (3, 4)
LCD.write_string("Cart Total")
lcd.cursor_pos = (3, 15)
lcd.write_string(str(totalCost))
entryF.append(entryS) #adding entry in Final Buffer
sleep(2)
except:
print("Unknown Barcode or Item Not Registered")
LCD.clear()
lcd.cursor_pos = (0, 0)
LCD.write_string("Item Not Found...")
lcd.cursor_pos = (2, 0)
LCD.write_string("Scan Again...")
sleep(2)
First, you pick out the product you want and scan its Barcode.
Verify the accuracy of the LCD.
Scan something else and perform the same thing
Once you have everything you need, scan the Barcode affixed to the thermal printer to initiate the billing process.
Collect the bill and use the Q.R. code to pay using a U.P.I. account.
Managing libraries is a specialty of library automation.
Each book is equipped with a barcode that the system uses to keep track of its current availability. The barcode scanner provides the librarian with up-to-date information on the books that have been checked out. Books can be checked automatically, allowing for less workforce.
Maintaining a stock-taking system.
Barcodes provide for more efficient product recognition and data deployment. Manually entering data at the front end raises the risk of human error, which can cause delays and financial losses. But the barcode scanner is highly accurate and rarely makes mistakes when processing product orders. Because the data is automatically recorded with each sale, this simplifies stock-taking by cutting down on time spent manually looking for items.
Reservations for travel
The billing procedure can be lengthy and frustrating at movie theaters, motels, and other establishments. Bills generated through electronic billing systems include a barcode or Q.R. code that can be easily decoded using a scanner kept by the relevant authorities.
Billing office
It lessens the likelihood of mistakes occurring during billing's manual data entry process. Barcode scanners have many applications in billing departments, including speedy data gathering and the ability to check pricing and promotions.
For Office Biometrics
A company's employees are obligated daily to record their attendance and clock in/out times. Scan the Barcode on their I.D. cards instead of having them manually enter their information.
For use in the production and logistics sectors
Using a barcode scanner, keeping tabs on company property is possible. A quick snapshot of the warehouse's inventory is provided. Raw materials utilized in production must also be sent to different markets. Consequently, there can be no mistakes in the labeling. As a result, it speeds up transactions and generates more money.
Reducing the likelihood of making mistakes and responding quickly to consumer requests are critical to growing the business. Time constraints can be met with more efficiency when both incoming and leaving shipments are monitored regularly. As industrial processes become increasingly mechanized, the cost of human labor declines.
On campus
The main features include tracking fixed assets like computers, lab equipment, machinery, etc. Teachers or employees responsible for the safety of their assets, such as the craft, can keep tabs on them with this feature. Barcode scanning keeps track of books and supplies that have gone missing in a library. A student's entrance and exit from the library can be quickly and accurately recorded using barcode scanners.
Industry of Health Care
Surgical supplies, patient specimens, pharmaceuticals, etc., must be tracked. Barcodes on patients' wrists allow doctors to quickly and readily verify that their care is being administered properly. These barcodes make it simple to record and monitor the previous distribution of prescriptions.
Governmental and Military Affairs
They take great care to ensure that sensitive information about the country does not leak. Problems with data recording or disclosure could lead to legal trouble. Official data can be kept safe with the use of barcodes.
Logistics
A worker working in logistics could be accountable for juggling multiple products at once, which increases the likelihood of making mistakes and sending out the wrong items. A barcode scanner can be used to automate this process with little room for error.
The Retail Industry
Including a barcode on each item will speed up the billing process by eliminating the need to enter each purchase manually. It will also make it simpler to view stock levels. Theft can be prevented by installing a barcode-based sensor on the exit door. In addition, this technology makes it easy to track the discounts applied to each item and ensure that they are still valid, reducing the need for human labor.
Barcode scanners prove essential for managing a wide variety of administrative processes. It appears that barcode scanning technology will continue to evolve in the future. We have seen how to construct our own "Smart Shopping Cart," complete with a barcode scanner to read the item's Barcode, retrieve the prices from the databases, show the information of the scanned object on an LCD for reference, and print the invoice using a thermal receipt printer. In the next tutorial, we will discuss How to design a Cryptocurrency Miner with Raspberry Pi 4. So, stay tuned. Have a good day.
Technology is changing fast. It’s constantly shifting and evolving. Tech is making our lives easier but it’s also creating new problems. It is changing the way humans behave and interact with one another. Technology is providing answers to things we never knew and solutions to problems we can’t solve on our own. There is a lot of innovation happening right now, especially in the field of engineering. Below are five technologies that are being innovated by engineers.
You’ve probably seen a video of a 3D printer or have heard about what they can do. 3D printing is changing fast and enabling us to do a lot with it. 3D printing software provides more tools and resources to print useful things for us. The medical industry has begun using 3D printed organs and other significant tools for the field of medicine. Engineers have taken 3D printing to a whole new level. It is getting to the point where we can 3D print anything we need. Think about it. Soon we will imagine things we want and simply print them.
Engineers are also helping innovate artificial intelligence (AI). With AI, there is no shortage of ways that our lives will change. We’re already experiencing it. Engineers were instrumental in creating AI chatbots that improve customer service and user experience . AI can analyze large sets of data. It can synthesize media using all the intelligence it has from the internet. AI is already solving problems that we used to deal with quickly. It is changing the way we live and think about the future. AI will continue to augment our lives in several ways, and engineers will facilitate this growth and, hopefully, steer it in the right direction.
One area of technology that will impact the way we live is our ability to urban farm and create more ways to capture carbon in the atmosphere. There are now examples of engineers creating living buildings, buildings that incorporate trees and other foliage into the design. There are also downtown farms. For example, there are now buildings that can be used for farming shellfish . These vertical buildings host aquariums of fish that are used for food. Engineers can work with environmentalists to create truly incredible infrastructure that could change the world. This is one area of innovation that shows promise for the future.
Optical engineering might seem like a consistent lane to be in, but this isn’t the case. Optical engineers have already innovated contacts, eyeglasses, telescopes, and more. This will only increase in the future. There are already plans for contact lenses that connect to the internet. Soon you will be able to see avatars, applications, and other online images simply with your contacts. You will be engaging with the internet on a whole new level. The optics are changing . Optical engineers will facilitate the shift from using phones to participating with the internet through virtual reality (VR).
There has been a lot of talk recently about the metaverse. This is what we are calling the world within technology we can engage with through goggles and headsets. Have you tried VR before? It used to be flawed but it’s getting better all the time. Engineers are making VR better and better all the time. It is getting more realistic and functional. There is also augmented reality, or AR. This is the technology that utilizes VR components with the tangible world. For example, remote medical surgeries are now a reality. With 5G internet, better AR, and engineering innovations, we can improve our way of life in many ways.
Engineering is also facilitating data , storage, and analysis. Engineers have created Cloud storage abilities and the capability to analyze large sets of data. Of course, AI will be able to analyze data a lot better than we will but storing data in the Cloud is how the AI will have it so organized. Data is easier to analyze when it is organized. Data has become one of the most valuable assets in modern business. When you have thoroughly analyzed data, you will have the ability to market to new customers, find new target demographics, and create both new products and services.
There is no shortage of ways that engineering is changing our world. Its relationship with technology continues to change. The way that we live is being augmented all the time. How will we think about these technologies in the future? With more and more innovation, the world will change around us. It’s an exciting perspective to look at the world through the engineer’s eyes.
, In recent years, additive manufacturing (AM) has become an increasingly popular topic in the aerospace industry. Additive manufacturing is the process of making three-dimensional objects from a digital file. It is also known as 3D printing.
In general, additive manufacturing builds objects by adding successive layers of material. This is in contrast to traditional manufacturing methods like machining or milling, which involve removing material from a block of metal or other material.
With technology evolving and becoming more widely adopted, additive manufacturing has transformed how aircraft are designed, built, and maintained.
This article will discuss some of the critical benefits of aerospace additive manufacturing.
Additive manufacturing provides greater design flexibility than traditional manufacturing methods. This is because AM enables the creation of parts with highly complex shapes and geometric structures that would be impossible to produce using subtractive processes like machining.
And this opens up new possibilities for engineers in aircraft design, leading to more innovative and efficient solutions.
For example, the most common type used in aerospace applications is called selective laser melting (SLM). SLM uses a laser to melt the metal powder into the desired shape. The advantage of SLM is that it can create complex aerospace components and shapes that would be difficult or impossible to create using traditional methods.
Here is an example of a complex design made through SLM.
Previously, products were made by assembling a wide range of individual parts. With additive manufacturing, products can be created using fewer individual parts since the designs are printed using a 3D printer at a time. This allows for more complex designs and saves time you’d otherwise spend in traditional assembling.
Aerospace manufacturers are always looking for ways to reduce manufacturing costs. One major way to achieve this is by adopting the aerospace additive manufacturing alternative. According to a survey conducted by Appendix, cost-effective manufacturing is among the most important benefits 3D printing offers to aerospace companies.
AM contributes to cost savings by creating complex designs with fewer steps and structural components. Traditional manufacturing methods waste a lot of material because it is impossible to use in the finished product. With 3D printing processes, only the amount of needed material is used, making it more efficient.
Also, additive manufacturing allows for greater customization, leading to reduced costs. For example, if a part needs to be made for a specific application, aerospace additive manufacturing can be used to create a part that is off the shelf. This saves the manufacturer from having to order custom parts from your aerospace suppliers , which can be expensive.
Additive manufacturing is generally much faster and more efficient than traditional manufacturing methods such as milling or casting. Besides the speed, it can produce parts with high accuracy and repeatability. This is because AM eliminates the need for tooling or molds, and parts can be produced layer by layer directly from digital 3D printing models with minimal material waste.
Storage requirements for aerospace equipment differ depending on the application. Some standard storage requirements include:
Temperature control: The equipment must be stored within a specific temperature range to prevent damage or malfunction.
Environmental protection: The equipment must be protected from harmful elements such as dust, moisture, or corrosives.
Storage requirements in the aerospace industry vary depending on the type of aircraft. However, aerospace industries are constantly looking for ways to reduce storage requirements, as storage space is a valuable commodity in this industry.
Additive manufacturing processes help minimize storage requirements by producing parts directly from a 3D printing model.
This reduces the required inventory since parts can be printed on demand instead of on storage carousels, as shown in the image below. Carousels are more common in traditional factories due to subtractive manufacturing methods, such as milling and turning, requiring much material and storage.
With aerospace additive manufacturing, parts are built up one layer at a time, so very little material is wasted. This means less storage is required to store the raw materials freeing up valuable space in factories.
Component weight is a critical factor in the aerospace industry. Every pound of weight eliminated from a single component allows for carrying additional payload or fuel, increasing the aircraft's range or performance.
In recent years, aerospace additive manufacturing has emerged as a promising technology for reducing the weight of aerospace components in the aerospace industry.
Additive manufacturing can create parts that are lighter and stronger than those that can be produced using traditional methods. This is because the additive manufacturing process does not require traditional cutting, drilling, or welding methods. As a result, less material is needed to produce a single component, which reduces its weight.
AM also allows for greater control over the process of manufacturing and chemical microstructures of materials. As a result, components can be designed with specific attributes like improved toughness or fatigue resistance. This reduces weight and decreases fuel consumption and emissions while improving performance and range simultaneously.
Finally, unlike traditional manufacturing, additive manufacturing enables general component design optimization, which helps with weight reduction. The result is lightweight structures. In traditional manufacturing methods, excess material must be added to compensate for errors and inaccuracies in the manufacturing process, resulting in heavier structures.
The aerospace industry is a critical part of our economy and our way of life. It produces and operates various aircraft, from commercial airliners to military aircraft. To keep up with the demanding needs of this industry, manufacturers are always looking for ways to improve their mechanical performance. One way that they are doing this is by using additive manufacturing technology.
Additive manufacturing has a transformative effect on the aerospace industry thanks to its many benefits, such as increased product complexity, reduced manufacturing cost, minimized storage requirements, and decreased weight of components.
As 3D printing technologies continue to evolve, more additive manufacturing applications will likely be found in aerospace, leading to an even more significant impact on the industry.
However, 3d printing technology is still relatively new, and there are not many standards in place. In addition, each manufacturer has its additive manufacturing processes and methods for creating parts, making it difficult to know if a part will meet the required specifications.
Hello, peeps! Welcome to another exciting tutorial on MATLAB in which we are discussing one of the most important windows of MATLAB that you are going to use the most. In the previous tutorial, we learned a lot about the basics of MATLAB and the different types of windows that are used in MATLAB and are present on the face of MATLAB when you launch it. There was a piece of interesting information about the basics of this fantastic development environment. This is the next step in the related tutorial in which we study the applications and workings of command windows in depth. Here is a glance at the topics that you are learning about today.
How can you define the command window of MATLAB in detail?
What are some examples of commands related to online help?
How can you use the useful commands on MATLAB related to the variable?
Give the information about the commands related to the files, directories, and the PC that you are using.
What are some examples of the type of equations that are solved in the command prompt?
Thus, let’s start learning.
Recall that the command window is the basic window that is shown in the centre of the screen when you fire up your MATLAB, and here, the pre-defined commands are run in the easiest way by merely providing the command and values. If it seems to be normal right now, then maybe you have unclear programming skills because programmers know that in most languages, the commands and functions have to be defined first.
Not only this, but the command window also performs another responsibility. In some programs, when we are using the edit window, the command window shows us the results and outputs of the calculations, if applicable. The usage of edit windows is not yet discussed in his tutorial, but you can understand that the command window shows us the numerical output and the command’s results when we allow it to do so.
As we have said earlier, the command window is used for different purposes, and therefore, at the beginning, we are telling you about the different ways to seek official help from MATLAB if you are stuck in any situation and do not know how to tackle it. The good thing about MATLAB is that it provides you with the maximum information and helps in different ways and it is made for students. Therefore, it not only provides you with the terms of help but also defines them in the easiest way so the students may know where they have issues in the calculations. So let’s start the process of finding help in different ways in MATLAB. Just follow the steps given below:
Launch your MATLAB software.
Go to the command prompt where the function catalogue is blinking.
Start writing the following commands to check what they do.
By writing this in your command window, you will get the list of the commands for which, MATLAB can help you by defining the introduction and codes of that particular command.
It creates a helpdesk for you and directs you towards the MATLAB official page where you can report and find help regarding your issues.
This command provides you with help regarding a particular topic. Assume that you want to get help related to MATLAB's "help" command, which was also mentioned above. You can type "help" instead of "topic" in this command. You will get the details all the time.
It is a special command that is used to get the help link and details in a separate window.
This is an interesting command that is designed to provide you with help related to the strings that we will use in the codes. If you are new to this concept, skip it for now because you are going to learn about it in detail in the coming sessions.
It is one of the most amazing commands in MATLAB where you can find demo examples of different types of code by merely writing a single word, and you will be directed to the official page of MATLAB where all the demos of various programs are present.
If you want to get the Readme files of MATLAB, you just have to write this command in the command prompt and you will get the required output.
This command has some different types of work. Every time you write “Why” in your command prompt, you will get a different type of sentence with a different meaning.
This is a command resembling the “clc” command where you can go to the start of the command prompt and all the results and writings will be cleared from the screen and you will start writing from the beginning.
This command is used to declare the variable globally. In other words, you will not have to declare the variable again and again in different sections, but it will be defined once and can be used anywhere in the program.
Here is another category that deals with variable or workspace information, and you can easily perform them as you have practised the commands discussed above. So here is the list of this particular type.
This command is used to get all the variables that are declared in the workspace in which you are working.
If you want to know the variables declared in the workspace along with their sizes, then you will use this command. In this way, by adding only one character, you can also examine the size of the variable.
Sometimes, or I should say, many times, we want to clear the screen so we may try other codes and commands. For this, you do not have to select all the content and then press backspace, but you just have to write a simple “clc” command and all the data will vanish from your screen. But be careful while using this command because once the data is removed, you will never get the same data back.
Consider the case when you just want to remove the specific lines of code or the variables and other code that are useful to you. Then you will use the clear command in a specific manner in which you will specify the variables that you want to remove from the screen and the memory. In this way, the declaration and erasure of data become easy.
As we said earlier, it may be a disaster in your code if you clear the instructions in the code that were supposed to be there in the command prompt, and in such cases, you can lock the function by putting the name of that particular function just at the place of “fun” in this command.
As we have defined the figure window in our previous lecture, if you have the results of your code in the form of a figure window and want to close it with the help of a simple command, then simply write this command and the window will be closed.
While using MATLAB, I face some cases where I have to think a lot about the directory and want to get information about different files saved in MATLAB by e. So, I found some interesting commands that tell me the exact information about the directories and files I am using efficiently and in great detail. Some of them are given below:
It changes the current working directory. It seems the same command we use in the command prompt of windows.
The purpose of this command is to see the content of the current directory.
This command is used to copy the content of the files that we are working on.
To remove the current directory from your MATLAB, we use this simple command.
It is an interesting command. You can access all the data on which you are working with the help of this simple one-word command.
Yes, it is right. You can find general information about your computer with the help of commands in the command prompt. MATLAB does not only work as simple software that works separately from the other functions of the computer but it is also connected to the internal system of your PC. For instance, if you want to know the basic information about your PC, then you have to see the commands given below:
This is my favourite command. You can have the time and date in the form of a vector wall clock by writing this on your command prompt.
The licence and version of MATLAB can be seen with the help of this command.
This command must be used when you want to compare your computer to other devices while MATLAB is running.
Many times, people do not know the type and specifications of the computer, and they can find them with the help of this command.
Keep in mind, just like some other programming languages, MATLAB is a case-sensitive language, and therefore, if you put these commands with different spellings or change the way of the writing that they were supposed to be, you will get an error. Usually, if the case or one or two characters are changed, MATLAB gives you the suggestions and, therefore, you can easily press the enter key and get the required work from MATLAB. Otherwise, you have to write the exact command.
Now, you know the basics and easy commands that are used in the command prompt, you can easily use the command prompt for different numerical problems. Now, we are starting MATLAB and solving the simplest numerical problems, and then we will move towards more complex problems.
First of all, have a look at the equation that we are going to solve in MATLAB.
4x + 2 = 18
Here, x is the variable, and we want to find the value of this variable. So, we are using the following code to get the required output. You must know that the 18 on the right-hand side is moved to the left-hand side and, therefore, the equation becomes
4x + 2 - 18= 0
4x -18 = 0
We will write this problem in MATLAB and will get the results:
As you can understand with the help of this image, we are declaring a variable with the name “equation” and then feeding the values of x and the constant into it. By default, MATLAB reads the equation from the right side, and it reads the rightmost value as constant, and after that, moving towards the left increases the value of the polynomial. So, MATLAB understood that 4 is the value of variable x.
Consider another equation that is shown as:
34x4 +45x² -12=0
Here, you can see that the cubic value of the variable x is missing, so in place of this value, we will write zero. So the code and the output of the equation given above are:
You can use any word instead of "equation" to declare the equation. Yet, be careful, you have to write the exact word in the root command to get the desired results. The roots command simply takes the equation, solves it, and provides us with the result instantly.
So, it was the day when we learned a lot about the command prompt and saw some amazing commands related to MATLAB that, when written on the command prompt, give us the useful required information, and we checked most of them during the lecture. Your homework is to check the missing commands and get the results related to MATLAB. We will do some complex calculations in the next session, and now you are ready to get the answers to the complex calculations and codes, so stay with us for more action.