The Engineering Projects

How to use Capacitive Touch Sensor in Proteus ISIS ?

Hello friends, I hope you all are fine and enjoying. Today i am going to share my new project's tutorial which is How to use Capacitive Touch Sensor in Proteus ISIS. It is a very interesting project, and we will be using a 555 Timer while designing this project. If you recall our previous project tutorial which was Angle Control of Servo Motor using 555 Timer in Proteus ISIS, in which 555 timer was generating PWM and was controlling the rotating angle of servo motor.

Now in this project, we have a little different context and now we will be using a 555 Timer in collaboration with Capacitive Touch Sensor. First of all, lets have a little introduction of Capacitive Touch Sensor. Well, if we talk broadly then, in Electrical Engineering Capacitive Touch Sensing is a Technology used in Capacitive Coupling. Capacitive Coupling is a technology which takes Human Body's Capacitance as an input and it measures anything which has a potential difference or  which is conductive or any static object which has a dielectric difference from that of air. While designing this technology, one side of the insulator is coated with the conductive material and a very small voltage is applied to this conductive layer. Now after applying the voltages to the conductive layer, a uniform electrostatic field is formed. After that if any conductor (suppose human finger) will come within the vicinity of this field or it touches the other non coated layer of the insulating material then a capacitor will be dynamically formed and if potential difference between both bodies is HIGH then the current will start to flow. That was a little introduction of Capacitive Touch Sensor, and now lets be practical and move towards the Hardware of the Above described tutorial.

You can download the complete simulation of above described project by simply clicking on the button given below:

Download Simulation Files

How to use Capacitive Touch Sensor in Proteus

• In this project, we are using 555 Timer in collaboration with Capacitive Touch Sensor. A 555 timer is an 8 pin IC. Pin # 6 is called threshold pin and for 555 timer threshold level is 5 volts.

• So, 555 timer will trigger above 5 volts and it will generate output which can be collected from pin # 3 represented as ‘Q’ which is output pin of 555 timer.
• While moving toward the simulation of project, first of all place all the components in the proteus workspace, as shown in the image given below:

• First of all we have place Capacitive Touch Sensor and after that we have placed a NPN transistor, then 555 Timer will come and at the output of 555 Timer we have added a LED. The complete circuit diagram ready for simulation is shown in the image given below:

•  As long as the finger is out of the vicinity of the electrostatic field, no potential difference occurs and the LED remains in the OFF state.
• Now if we move the finger towards Capacitive Touch Sensor, then and when the potential difference reaches up to 0.6 volts, then 555 triggers and it generates output voltages across LED which are 5 volts but in some cases voltages are lost due to series connected resistances. This phenomenon is shown in below image:

• Now if we further move the finger and take it completely near the sensor, then at this point max potential difference will occur between both point (finger and conductive layer). An important thing to note here is that, we have change the location of our interrupt ( finger) but, same voltages are appearing across LED which are 4.91 volts in this case. It can also seen in the figure given below:

• Now, if we summarize the whole project, then we have seen that the movement of finger is in fact controlling our output. When the finger was out of vicinity of the sensor, then LED was OFF. When we moved the finger in forward direction and came in the vicinity of Electrostatic field, then Sensor gives signal to 555 Timer and Timer makes LED to glow.
• Here's a video demonstrating Capacitive Touch Sensor in Proteus ISIS.

Applications Of Capacitive Touch Sensor

Capacitive sensing touchscreens are now a days commonly used in Digital Audio Players, Mobile Phones and Tablet Computers. Capacitive touch sensors also have the ability to replace Mechanical Buttons. Back in 1928 Russians invented a music instrument known as "Theremin" , in which The Instrument Player was able to control the volume and pitch of the sound without physically touching the instrument. Capacitive Touch Sensors are of basic level but they are back bone of large industrial projects and are widely used in designing some other sensors like:

1. Position sensor.
2. Humidity sensor.
3. Fluid or Water level sensor.
4. Proximity sensor etc..

Alright friends, that’s all for today, I hope I have conveyed some knowledge and helped you people in some way. If you have some queries, then ask in comments. Subscribe us via email to get these tutorials straight in your inbox. Till next tutorial, take care and be safe !!! :)

Seven Segment Display Using 555 Timer in Proteus ISIS

Hello friends, hope you all are fine and enjoying. Yesterday I got a mail from a friend, and he requested me to explain a tutorial about Seven Segment Display. So today, I am going to share my new project tutorial which is Seven Segment Display using 555 Timer in Proteus ISIS. It is a very simple project to understand Modern Digital Electronics.

As you all know, now a days all the Digital Display’s uses Seven Segment Display. So first of all let’s have a little introduction about Seven Segment Display. How they are fabricated and how their LED’s glow in such a beautiful manner? Seven Segment Display (SSD) is the form of electronic device, used to display decimal numbers. Seven Segment Displays are commonly designed in Hexagonal shape but according to our project’s requirement we can also design them in some other shapes like rectangle, triangle, trapezoid etc. Seven Segment Displays may uses LIQUID CRYSTAL DISPLAY (LCD) or LIGHT EMITTING DIODE (LED) for each display segment. In Seven Segment Display all the positive terminals (Anode) or all the negative terminals (Cathode) are brought together to a common pin and such arrangements are known as “Common Anode” or “Common Cathode” arrangement. In this project we will be using Common Cathode arrangement and Hexagonal shape of Seven Segment Display. A simplest form of Seven Segment Display is shown in the image below:

From the above shown image, we can see that we have total 7 LEDs and we will make them glow in such a scheme that the final image will look like a Numerical number. Now if you recall one of our previous project tutorial which was Sequential LED Blinking using 555 Timer, In that project, we are using a 555 Timer in collaboration with a Shift Register. 555 timer continuously provides clock to the Shift Register and Shift Register gives data to its output pins in parallel manner. In today's project, we are also going to use the same concept. We will use a 555 Timer which will continuously provide clock to Shift Register it will enable it's pin accordingly. We can gather this whole information into a single table and also the sequence in which LED's will blink. Such table is called TRUTH TABLE and it is shown in the image given below:

In the above image, '1' means ON state and '0' means OFF state of a particular LED of Seven Segment Display. Above was a little introduction of Seven Segment Display and now, lets move towards Hardware and see How this beautiful display is actually formed.

You can download the complete simulation of above project by simply clicking on the image given below:

Download Seven Segment Display Project Using 555 Timer

Seven Segment Display Using 555 Timer

• First of all place all the components in your proteus workspace, as shown in the image given below:

• First of all 555 Timer is installed, after that a Shift Register is added. 555 Timer will give clock to the Shift Register. Since we are using common cathode arrangement. So, the 7 input pin of SSD  are connected to the output pins of Shift Register and the common cathode pin is connected to circuit's main cathode. If you have placed all the components in their exact positions and all the connections are OK. then, the resultant simulation will look like as shown in the image below:

• Now if you look closely at the upper portion of the image then, you will notice that i have added 2 buttons in the circuit. Left Button in Button # 1 and Right Button is Button # 2.
• If both the Buttons are kept open and when you will run the simulation then, numerical values will start to come on seven segment display. you can also see it in the below image:

• Now the switching of button # 1 includes a very interesting feature. First of all play the simulation and Digits will start to run on Seven Segment Display and at any stage when you will press Button # 1 then Seven segment display will vanish but counting will keep on going in the back. And when you will open the Button#1 again then it will show that digit, up-to which counting have reached. Below is a very interesting feature included:

• During State#1 when Seven Segment Display was showing digit no.2 , we pressed button#1 then, display vanished which can be seen in the state#2. After that when we re-opened the switch#1 then, Seven segment display didn't show the digit no.3 but it shows digit # 8. and this thing can be seen at state#3.
• Now moving forward, the function of switch # 2 is very simple and easy. During simulation running, when we will press the Button # 2 at any instant then, display will immediately stop at that point. So, we can say that this project can also be used as stop watch and button # 2 controls the stop watch. It can also be seen in the image below:

Seven Segments Displays have a large no of applications. Some of them are listed below:

1. Digital Clocks.
2. Electronic Meters.
3. Basic Calculators.
4. Electronic Devices to Display Numerical Values. (Generally 14-segments or 16-segments display is used to display full alphanumeric values).

Alright friends, that’s all for today, I hope I have conveyed some knowledge and helped you people in some way. If you have some queries, then ask in comments. Subscribe us via email to get these tutorials straight in your inbox. Till next tutorial, take care and be safe !!! :)