The Engineering Projects

Automatic Plant Watering System using Arduino

Hello friends, I hope you all are doing great. In today's tutorial, we are going to design a Proteus Simulation for Automatic Plant Watering System using Arduino. We have designed this project for engineering students as it's a common semester project, especially in electrical, electronics and mechatronics engineering.

The two most significant hazards to the agriculture industry are the need for extensive labor and a scarcity of water. According to the World Wildlife Fund (WWF) organization, water shortages might affect two-thirds of the world's population by 2025, putting both the ecosystem and human health at risk. The use of automatic plant watering systems eliminates both of these problems by watering plants at specified times and amounts while monitoring their hydration levels through measuring moisture in the soil surrounding the plants. Automatic plant watering systems can be used in homemade gardens and can also be deployed in fields for large-scale use. Whenever designing an automatic watering system, it is important to keep in mind that the system should be expandable, allowing for the simple integration of new devices in order to broaden the applicability of the system.

Where To Buy?
No.	Components	Distributor	Link To Buy
1	Buzzer	Amazon	Buy Now
2	LEDs	Amazon	Buy Now
3	DS1307	Amazon	Buy Now
4	LCD 20x4	Amazon	Buy Now
5	Arduino Uno	Amazon	Buy Now

Software to Install

We are not designing this project using real components, instead, we are going to design its Proteus simulation. So, first of all, you should Install Proteus Software itself. Proteus software has a big database of electronics components but it doesn't have modules in it. So, we need to install Proteus Libraries of a few components, so that we could simulate them. So, these are the PRoteus libraries which you should install first, before working on this project:

• Arduino Library for Proteus: Adds Arduino boards to Proteus components list.
• LCD Library for Proteus: Adds LCD module in Proteus Suite.
• Water Sensor Library for Proteus: Add Water Sensor in Proteus components list.
• DS1307 Library for Proteus: Adds RTC module DS1307 in Proteus Environment.
• Soil Moisture Sensor Library for Proteus: Adds Soil Moisture Sensor in Proteus software.

You can download this complete project i.e. Proteus Simulation & Arduino Code, by clicking the below button: Download Complete Project Note: You should also have a look at these other Proteus Libraries:

• Latest Proteus Libraries for Engineering Students V2.0.
• Proteus Libraries of Digital Sensors.
• Proteus Libraries of Embedded Sensors.
• New Proteus Libraries for Engineering Students.

Project Overview:

Three main components of an autonomous watering system are:

• Water Level Sensor: monitors the water reservoir level.
• Moisture Sensor: monitors the soil moisture level.
• RTC module: responsible for supplying water to the plant at predetermined intervals or at a predetermined time.
• Arduino UNO: serves as a hub for connecting and controlling all these components.

It is necessary to integrate the water level sensor with the microcontroller before it can be installed within the water reservoir. The location of the water level sensor within the reservoir is variable and is determined by the user and the application for which it is being utilized. The Arduino receives continuous data from the water level sensor and warns the user when the water goes below a certain level, either by an alarm or a buzzer, as appropriate.

The soil moisture sensor operates in a manner similar to that of the water level sensor. The tip of the sensor is inserted into the soil near the plant, and the sensor is activated. In the case of a moisture sensor, the closeness of the sensor to the plant is also variable, and the user may adjust it depending on the features of the plant for which it is being used. In vast agricultural fields, a single sensor may be used for numerous plants if they are closely spaced and their hydration levels can be determined by measuring the soil moisture at one location that overlaps with another spot on the soil surface.

The RTC module operates on the same concept of time monitoring in the background as other electronic devices such as computers and smartphones; even when these devices appear to be turned off, they continue to keep track of the current time. The RTC module, on the other hand, is capable of exchanging time information with the Arduino board. On a specific day of the week, at a specific time of day, the Arduino is pre-programmed to turn on the water pump and turn off the water pump after a specified length of time.

Components Needed:

1. Arduino UNO
2. Water Level Sensor
3. Moisture Sensor
4. RTC Module (DS1307)
5. LCD
6. 4 LEDs
7. Buzzer
8. Relay
9. Water Pump
10. PCF8574

Component Details:

Arduino UNO:

• Arduino UNO is a programmable microcontroller board.
• It contains Atmel's ATMega328 as is based on that microcontroller.
• The Arduino board also contains an in-built voltage regulator to protect it from burning out and supports serial communication to help programmers.
• The Arduino board is culturally programmed through the Arduino App designed by the board's developers and the programming is done in C language.
• The Arduino App compiles code and interfaces the firmware into the Arduino hardware.
• Arduino UNO has 14 digital I/O pins out of which 6 are PWM pins as well.
• Arduino also takes analog inputs and has 6 analog input pins.

Figure # 1: Arduino UNO

Soil Moisture Sensor:

• The soil moisture sensor is a resistive sensor that consists of two electrodes with a small charge and the resistance in those electrodes is measured and then the resistance in between the soil is used to find the moisture levels.
• A soil moisture sensor normally comes equipped with an amplifier such as LM393. It has a VCC, GND and analog output pin.

Figure # 2: Soil Moisture Sensor

Water Level Sensor:

• The water level sensor is a module that helps calculate the amount of liquid in a container.
• When a liquid is present in the tank, the Submersible level sensor detects the hydrostatic pressure generated by the liquid.
• Since hydrostatic pressure is a measure of two variables, the first of which is the density of the fluid and the second of which is the height of the fluid, it is a useful tool.

Figure # 3: Water Level Sensor

RTC Module:

• RTC stands for real Time Clock and as the name suggests the module keeps track of time even when the external power supply is cut off.
• It has a battery cell installed within it for that purpose, moreover, it is capable of communication with other devices such as Arduino too.

Figure # 4: RTC Module

Relay:

• Relays are basically electrical or electromechanical switches that operate on the principle of magnetic field controlling the switching within the relay.
• A relay has two modes of operation, normally open and normally closed.

Figure # 5: 12V Relay

PCF8574:

• The PCF8574 is a silicon-based CMOS integrated circuit.
• Using the two-line bidirectional bus enables general-purpose remote I/O extension for the majority of microcontroller families (I2C).
• It is used in our project for I2C communication of LCD.

Figure # 6: PCF 8574

 

Proteus Simulation of Plant Watering System

Now, let's design the Proteus Simulation of Plant Watering System first and then will work on the Arduino Code.

• First of all, make sure that Proteus is installed on your computer and download all the necessary libraries for Proteus beforehand.
• For this project, you will need libraries for Arduino, LCD, RTC Module, Water Level Sensor and Soil Moisture Sensor. Make sure that you read how to use each library in Proteus as well.
• Open a new project on Proteus, import all the components required and place them within the working area or the blue line of Proteus.
• Select below components from Proteus Components' library:

Circuit Diagram and Working:

• Now, place these components in your Proteus workspace, as shown in the below figure:

• For the water level and moisture sensor, place a variable POT(potentiometer) at the test pin and place an RC filter at the output pins. (This is only for simulation purposes)
• Start with the input side of Arduino and connect the soil moisture, water level output pins to the A1 and A0 pins of Arduino respectively.
• To use the LCD for I2C communication, Place PCF8574 and connect with LCD.
• Connect the SDA and SCL pins of PCF8574 and the SDA and SCL pins of the RTC module with the SDA and SCL pins of Arduino.
• For the output side of Arduino, Connect the D7 to the relay controlling the pump.
• Connect the buzzer at D2 and the LEDs to their respective Arduino pins as well.
• Make sure appropriate power and ground are provided to each component. With that the making of the circuit on Proteus is complete.

Figure 7 shows the circuit diagram of the system. Proteus was used to simulate the circuit and Arduino App was used for the simulation of the Arduino code. The circuit was designed in a way that is easy to understand and further integrated easily. We will now go through a step-by-step guide on how the circuit was built.

Figure # 7: Proteus Circuit diagram

Arduino Code for Plant Watering System

A normal Arduino code has two main segments:

• void setup
• void loop

We will look at both of them separately here.

Declaration Code

• The first step in setting up our code is defining libraries, download if you don’t have any libraries already integrated in the Arduino App.

Figure # 12: Arduino Code

• The next step in the code is tone definition for buzzer and pin definition of variables being used in the project.

Figure # 13: Arduino Code

• After pin definition, the variables used must be defined so that Arduino knows where to find them and how to identify them.

Figure # 14: Arduino Code

• The next step is defining the system messages that will appear on the LCD.
• It is not necessary to define those messages in the setup, they can be easily defined within the main code but it is an easier way to define those beforehand and call them whenever needed.
• This is especially useful when a system message is used multiple times in the code.

Figure # 15: Arduino Code

• Now we define the objects being used in the project.
• The two objects being defined are the RTC module and LCD. In the syntax below we used 20x0 in the argument for the LCD, that is because there are no libraries for I2C LCDs and we had to turn a simple LCD into an I2C LCD by the means of PCF8574.

Figure # 16: Arduino Code

Void setup:

Now we start the programming of void setup.

• At first is the initialization of various components, such as initializing the RTC module and setting the time and date of RTC with respect to our computer.
• Wire initialization and library are used for I2C communication.

Figure # 17: Arduino Code

• The next step is defining the digital pins of Arduino being used as input or output pins and displaying the initial message on our LCD.

Figure # 18: Arduino Code

 

Void Loop:

• The first step in the loop is to read the date and time from the computer through the RTC and read the values from the sensor.
• Since this part of the program runs in the loop, Arduino will keep reading and refreshing the sensor inputs every time the loop starts.

Figure # 19: Arduino Code

• In the next segment of the code, we will check various conditions of the sensor values and RTC and actuate our outputs on the basis of these conditions.
• At first, we check the water level of the container, if it is below the set level, Arduino will actuate the buzzer to alarm the user of low tank on LCD.

Figure # 20: Arduino Code

• In the next step, we check the values of the moisture sensor and place the conditions in three categories, namely, moist soil, soggy soil and dry soil.
• The Arduino will light up the respective LED whenever its condition is true. Red LED for dry soil, yellow LED for soggy soil and green LED for moist soil.
• The LCD will also display respective messages for each of those conditions.
• The following code is for the condition of dry soil.

Figure # 21: Arduino Code

• The following code is for the condition of moist soil.

Figure # 22: Arduino Code

• And finally the code for the condition of soggy soil.

Figure # 23: Arduino Code

• In the next step of the code, we check the condition of time, whether it is time to water the plants or not and the condition of the water reservoir to see its level as well.

Figure # 24: Arduino Code

If you see the code closely, you may see the function of the right hour, which is called various times in the main code. The function code in itself is written at the bottom of the main code. This function is used for displaying the time and date on the LCD and also for fixing the date and time.

Results/Working

1. Open Arduino and generate a hex file for that program.
2. Put the hex file in the Arduino UNO board placed in Proteus.
3. Run the simulation.

Figure # 8: Proteus circuit simulation when soil is soggy

Figure # 9: Proteus circuit simulation when soil is moist

Figure # 10: Proteus circuit simulation when soil is dry

Figure # 11: Proteus circuit simulation when soil is dry and it is time to water the plant

As you can see from figure 8 that our simulation is running according to the program set at Arduino. You can increase or decrease the values coming from the sensors through the Potentiometer. So, that was all for today. I hope you have enjoyed today's lecture. If you have any questions, please ask in the comments. Thanks for reading.

Databases and CRUD operations in C#

Are you here to learn about Databases and CRUD operations in the C# programming language? If so, then you will be an expert in no time. Learning Databases and CRUD operations in C# is not a piece of cake. But, if you know all the terms and steps of CRUD operations and databases in C#, it will not be rocket science for you. This article contains all the information you should know regarding databases and CRUD operations. So, keep reading till the end!

C# Programming Language: An Overview 

We know that you are already aware of the C# programming language. So, here is a quick overview of the C# programming language before we move to the actual topic:

C#, also known as C-Sharp, is an object-intended coding language that operates on the .NET Platform and is developed by Microsoft. ISO and ECMA have certified the C# programming language. C# is a broad programming language that can help accomplish hundreds of activities and purposes in different fields. It resembles Java, C++, and other programming languages but, it is truly one of a kind. The best thing is that it is object-oriented and is easy to use. It has an infinite list of advantages.

Some of the advantages of the C# are listed below:

• C# programming language offers automated garbage pickup.
• In C# programs, classes may be specified within domains.
• No obligation to add the “.h” extension within header folders.
• Because non-Boolean values are not utilized as conditionals, the scripts are less vulnerable to errors.
• Multithreading is genuinely uncomplicated in C# as compared to other programming languages like C++ or Java.
• All parameters in the C# are immediately set to their standard settings before being utilized.
• C# offers reflection skills, which means it can look at and change its composition at execution.
• With the help of the C# programming languages, many apps and programs have been built like KeePass, Banshee, Paint.NET, FlashDevelop, and many others. In fact, the application where I am writing this article is also an application of the C# programming language (Microsoft Word).

All the above advantages make the C# programming language stand out in other languages. It is undoubtedly the most contemporary and exceptional language out there!

What is a Database In C#?

Before we begin learning about CRUD operations in a database within the C# programming language, it is crucial to know what a Database is.

A database is basically a coordinated set of formatted data kept digitally within a computer network. A database administration tool is generally in charge of a dataset. The DBMS, the dataset, and the programs that interact with these are collectively called a database platform. Every database operation can access a single relational database. It is generated as an inclusion within the data catalog by the data proprietor (usually a database manager with authority for that collection), who gives it a title and a specification. Several databases utilize structured query language (SQL) when generating and accessing data.

What is CRUD?

Here is the most awaited section of the entire article: CRUD operations. Please grab a notebook to note every detail for your better understanding. And if you do not wish to write these, you can always read our article from the website. Let us begin:

The abbreviation CRUD refers to Create, Read, Update, and Delete in software coding. Permanent memory has these four primary functions. Additionally, every letter of the abbreviation may relate to every functionality within a relational network program that is linked to a standard HTTP service, SQL declaration, or DDS action.

It may also apply to consumer-interface standards that let users browse, explore, and alter data using computer-based documentation. Objects are viewed, produced, modified, and removed in this way. Furthermore, CRUD is data-driven, and HTTP operation verbs are regulated.

Standard CRUD Operations In C#

The CRUD feature is present in almost all programs. CRUD is something that every coder has to use at some stage. In the C# programming language, CRUD operations in the database are quite crucial to learn because they are a fundamental component of programming. CRUD is important because of its Create, Read, Update, and Delete features. A brief explanation of these features is listed below:

• CREATE Operations: Inserts a fresh entry using the INSERT command. This operation is required when we wish to add new data to the database. It basically enables you to add extra rows to your table. When you use the INSERT INTO command, the system will show two possibilities. You can choose the one which is according to your requirement. The two possibilities are:

• READ Operations: The READ operation retrieves table entries depending on the main key inside the given variable. It works in a similar way to the search feature.
• UPDATE Operations: Performs an UPDATE assertion on the database depending on the main key provided for an entry in the WHERE statement. You must specify the destination table and attributes to be modified when using UPDATE. The corresponding variables and the rows are also required. Use the code below to make changes to a preexisting record:

• DELETE Operations: Erases a specific order within the WHERE statement. Certain relational database systems may enable a final delete or a temporary delete, depending on the requirement. The DELETE code is:

• Here's the table, showing all operations with their description:

Standard CRUD Operations In ASP.NET MVC Utilizing C#

In this section, we will discuss the steps required to operate the standard CRUD operations in ASP.NET MVC within the C# programming language. So, please pay extra attention to this section so that you do not have to face any difficulty while coding.

You must be thinking about the term MVC. Well, MVC abbreviates for Model View Controller. It is actually a development paradigm that isolates the business strategy from the display strategy and information. In a nutshell, it is a framework for designing online applications. According to MVC, the program can be divided into three layers:

1. Model Layer: The Model element relates to everyone's data-associated reasoning. It will reflect the content being transmitted among the Display and Controlling portions, as well as any additional business logic-associated data. A Client class, for example, will receive client details from a server, change them, or utilize the content.
2. View Layer: The View element is used for the UI functionality of the device. For example, the Client view will have all of the UI elements that the final user encounters, like input forms, dropdowns, and others.
3. Controller: Controllers serve as a link among the Framework and View elements to execute all administrative functions and incoming applications, manipulating information with the Framework element, and interacting with Viewpoints to display the final result. For example, the Client manager would manage all activities and entries from the Client Page and use the Client Model to refresh the database.

Now that you know about the MVC, we can begin the discussion of the steps of CRUD operations in C#:

• Construct A Database Using The Columns Listed Below: It is merely a demonstration to ensure that you comprehend the script. You may construct your custom database based on your requirements. You can also understand it better by the illustrations in each step like the one below:

• New Project: Build a new project in Visual Basic.

• Create a Fresh Record: Next, within the freshly formed controller, enter the following script to generate a fresh record within your dataset.

Afterward, select the initial activity outcome and select AddView. Choose to Generate as your theme, model type as your developed model, and info context category as your EDMX developed prototype. After that, execute the project.

• Read: Next, to view the latest values on your display, use the code provided below.

Then, insert the View. However, make sure the style is set to List. After that, launch the project.

• Update: Now, use the following code to modify the present record.

Next, insert a view in the same way you did before, but ensure to set the theme to Edit. After that, launch the project.

• Delete: To erase an entry from the system, use the following code.

Now, just set the theme to Delete and execute the program.

Please remember that you can always change the HTML according to your needs. We hope that you understood how CRUD operations work in databases of the C# programming language.

CRUD Operations in C# Connecting SQL Database

We want our readers to have crystal clear concepts regarding CRUD operations in the C#. That is why we also included this brief section of CRUD operations in C# connecting the SQL Database. Let us begin:

• Add DLL: First, you must include Dynamic Link Library (DLL).
• Namespace: To link to a SQL system, you can utilize the System.Data.SqlClient; namespace.
• Declaration: Next, you should specify the relationship string beyond the class.

• Insert the Data: Enter data into the system as shown below:

• Update: Afterwards, you have to update the record like the code mentioned below:

• Display: Then, display the information like the code below:

• Delete: Then, follow the code below to erase the record.

• Use Clear Technique: Lastly, utilize the Clearing technique to remove all the text fields, as shown below:

Please remember these steps. If you mess up in one step, your program will not execute the right way. So, it would be great for you if you note the steps down!

Benefits Of Using CRUD Operations

Now that you know about the launch of CRUD operations in databases within the C# programming language, it is time to know the benefits of using CRUD operations. You must have this question that why do programmers prefer CRUD? In simple words, developers use CRUD because of its exceptional productivity. Additionally, performing CRUD operations protects against SQL manipulation attacks. Because all SQL Entries utilize saved methods rather than string synthesis to generate flexible queries from client input info, everything entered into a variable is quoted.

It would not be wrong to say that CRUD is just too crucial to be overlooked. Mastering it initially can help you feel more confident when working with unknown stacks. CRUD Operations help in our daily desktop tasks. Some of these are:

• Signing up for a webpage
• Saving a hyperlink in your account
• Modifying configurations
• Deleting a Facebook status

These are just some of them. CRUD is a part of everyone’s life whether one is a programmer or not.

CRUD Restricts Casual Surfing and Changes

Program permissions are a SQL Administration feature that allows code to alter credentials without requiring the person's permission. Individuals should have the necessary rights on the relational records to execute ad hoc SQL queries. Clients can view and change data in apps like Microsoft Excel, PowerPoint, and others after authorization is allowed. Customers can even ignore the app's corporate rules.

However, it is an undesirable scenario that may be avoided by using the Application Authority. Such kind of flaws can be prevented by combining database access protection with an Application License. Because Application licenses are uploaded to the system via a recorded method, CRUD is required. It can also be done by providing authorization to run the CRUD saved methods and removing immediate table entry.

After an Application Account is established, authorization and passcode are granted. The passcode is also hard to change because it is programmed into the program. CRUD is indeed the procedure to utilize while modifying data. Thus, the world of programming would be incomplete without CRUD Operations.

Summing Up

In this article, we discussed the CRUD operations in databases within the C# programming language. We also discussed Standard CRUD Operations In ASP.NET MVC as well as in Connecting SQL Databases Utilizing C#, with some benefits of using CRUD. These might seem complicated to you. Once you become an expert, all the CRUD operations in the C# will not be rocket science for you. Just make sure to follow all the steps correctly to avoid any mistakes.

Happy Programming Precious Readers!

ESP32 Programming Series: Install ESP32 in Arduino IDE

Hello everyone, I hope you're all doing well. In the previous lecture(Chapter 0: ESP32 Pinout), we discussed the ESP32 features & specs in detail. Today, we are officially starting this ESP32 Programming Series. In this ESP32 Programming Series, we will start with basic concepts and will gradually move towards complex topics. I will try to keep this ESP32 series as simple as I can. But still, if you encounter any issues, please ask in the comments, will try to resolve the issues as soon as possible.

As ESP32 has numerous features & applications, so I have divided this series into different sections. I have named the 1st section "ESP32 IDEs". In this section, we will discuss different IDEs used to program ESP32 boards. In each Chapter of this section, we will install one of these ESP32 IDEs and will test a simple LED Blinking Code in it. We will set up the ESP32 Development Environment for Windows, Mac, and Linux users.

As I am sharing the 1st Chapter today, so first we will unbox the ESP32 board, set up the most commonly used ESP32 IDE i.e. Arduino IDE, and test a simple WiFi Scan Code on the ESP32.

Here's a video lecture for better understanding:

Where To Buy?
No.	Components	Distributor	Link To Buy
1	ESP32	Amazon	Buy Now

ESP32 IDEs

IDE is an abbreviation of Integrated Development Environment. IDE is a software package used to write & compile the code. As ESP32 is one of the most popular microcontroller boards, there are numerous third-party IDEs available to program it, and each IDE supports its own programming language. So, if you are a C# developer or an Arduino expert, you can quickly and easily get your hands dirty with ESP32. The below table shows the most commonly used ESP32 IDEs along with their supported programming language:

ESP32 IDEs
No.	ESP32 IDEs	Programming Language
1	Arduino IDE	Arduino C
2	Thonny IDE	MicroPython
3	Visual Studio Code	Arduino C
4	PlatformIO IDE	C++
5	ESP-IDF(official IDE by EspressIF)	C
6	nanoFramework	C#

In today's lecture, we will install the Arduino IDE and configure it for ESP32 Programming. So, let's get started:

Install ESP32 in Arduino IDE

First of all, we need to install the Arduino IDE itself. To program ESP32 with Arduino IDE, we need to install the ESP32 Boards in Arduino IDE. Before installing the ESP32 Boards, we first need to add a JSON File containing information about ESP32 Boards. JSON format is used to share information between two computers. So, this JSON file will add the information of ESP32 boards in the Arduino IDE. So, let me summarize these 3 steps in proper order:

1. Installing Arduino IDE
2. Adding ESP32 JSON File
3. Installing ESP32 Boards
4. Installing COM Port Driver for ESP32(if COM Port not detected automatically)

Installing Arduino IDE

We need to first download & install the Arduino IDE.

• Download Arduino IDE from its official website, make sure to download the latest version.
• Installing Arduino IDE is quite simple, but if you are having issues, have a look at this Arduino IDE Installation Guide.

After installing the Arduino IDE, we need to add the ESP32 JSON File in it. So, follow the below steps:

Adding ESP32 JSON File in Arduino IDE

Steps to install ESP32 JSON File in Arduino IDE:

• Here's the link to the ESP32 JSON file: https://images.theengineeringprojects.com/software/esp32.json
• Open Arduino IDE and navigate to "File > Preferences", as shown in the below image:

• In the Arduino Preferences Window, you will find a textbox named "Additional boards Manager URL".
• Add the ESP32 JSON File link(provided above) in it, as shown in the below figure:

• If you have already added any third-party board URLs, then add a comma (,) between the JSON links OR click on the button and it will open up a new window, add URL in the new row, as shown below:
  

• Click "OK" to close the Preference Window.
• Once you close the Preference Window, Arduino IDE will extract the information of all ESP32 boards by downloading the ESP32 JSON file.

Now, we are ready to install the ESP32 Boards in Arduino IDE:

Installing ESP32 Boards in Arduino IDE

• In the Arduino IDE, click on "Tools > Board > Board Manager", as shown in the below figure:

• It will open up a Board Manager Window in Arduino IDE.
• From this Board Manager, we can install the packages for third-party modules.
  
• In the Board Manager, make a search for "ESP32" and you will get many third-party ESP32 packages.
• Here, we need to install the "ESP32 by Espressif Systems" as it's the official package, I have highlighted it in the below image:

• So, click on the Install button to install ESP32 boards in Arduino IDE.
• Arduino IDE will take some time to install the ESP32 package.

• Once installed, click on "Tools > Boards > esp32" and you will find a list of newly added ESP32 boards, as shown in the below figure:

• From this list, we will select "ESP32 DEV KIT V1", it's the most commonly used ESP32 board.

• In the COM Port, select the available COM Port, in our case, it's COM5:

In some cases, the Arduino IDE won't automatically detect the ESP32 COM Port, so here we need to install the COM Port driver for ESP32. Let's do it:

Installing ESP32 COM Port in Arduino IDE

If you don't find the ESP32 COM Port in the Port Section of Arduino IDE, then you need to install the COM Port Driver manually. So, follow the below steps:

• Download the Windows COM Port Driver by clicking the below button and install it on your computer:

CP210x_Windows_Drivers

• If you are using 32-bit Windows, then install the x86 version and if working on 64-bit Windows, then install the x64 version.

After installing this COM Port Driver, restart your Arduino IDE and it's recommended to restart your computer as well.

So, we have successfully installed the ESP32 Boards in the Arduino IDE. Now, let's upload a simple LED Blinking Code in the ESP32:

Code Upload to ESP32 from Arduino IDE

Now that the Arduino IDE is ready to handle the ESP32 Dev Kit module, you can write the code for the ESP32 module. We will just upload a simple WiFi Scan Code to verify that our ESP32 installation is correct.

• Open Arduino IDE and navigate to "File > Examples > WiFi > WiFiScan".

• Click on the Tools and verify that you have selected the correct ESP32 board and the COM Port.
• Now, click the "Upload " button to upload the code to the ESP32 board.
• If the code is uploaded successfully in the ESP32 board, you will get the confirmation message in the Output pane, as shown in the below figure:
  

Now open the Serial Terminal and you will start receiving the List of all available WiFi connections, as shown in the below figure:

That concludes today's discussion. We hope you found this post informative. In the next tutorial, we will install the ESP32 Boards in the Visual Studio Code. If you have any questions, please ask in the comments. Take care. Have a good day.

I2C communication with STM32

Hello friends, I hope you all are doing great. In today's lecture, we will have a look at the I2C Communication with STM32 Microcontroller board. I am going to use the Nucleo board for today's lecture. In the previous lecture, we have discussed STM32 Serial communication both in Interrupt Mode and polling Mode. Today, we will study another way of communication(i.e. I2C) with STM32. So, let's first have a look at what is I2C Communication:

Where To Buy?
No.	Components	Distributor	Link To Buy
1	STM32 Nucleo	Amazon	Buy Now

What is I2C Communication?

I²C (Inter-Integrated Circuit) is a two-wire serial communication system used between integrated circuits. Like any serial protocol, one of its advantages is that of using only two lines that transmit or receive a sequence of bits, the limit is the communication speed which has been improved over the years.

The bus was conceived and developed by Philips (now NXP) It was designed to overcome the difficulties inherent in the use of parallel buses for communication between a control unit and various peripherals.

Serial transmission is a mode of communication between digital devices in which bits are sent one at a time and sequentially to the receiver in the same order in which they were transmitted by the sender. Although the communication modules are more complex than the parallel transmission, the serial mode is one of the most widespread especially in communications between chips that must communicate with each other over great distances, because:

• it requires fewer wires and pins available on the integrated circuit with a consequent reduction in costs and space on the board;
• is more tolerant of interference and transmission errors;
• up to 128 devices can be connected to each other

I2C Pinout

• SDA (Serial Data) is the line where master and slave send or receive the information (sequence of bit);
• SCL (Serial Clock)  is the line dedicated to the clock to synchronize the data flow.

SDA and SCL lines need to be pulled up with resistors. The value of these resistors depends on the bus length ( ie the bus capacitance) and the transmission speed. The common value is 4.7kO. In any case, there are many guides to size them and we refer their reading to the more attentive reader.

The transmission mode is Half-duplex ie the transmission between devices is alternated.

As shown by the previous image, we can use this communication to put in communication different peripherals as Analog-Digital Converters (ADCs), Digital-Analog Converters (DACs), EEPROM memories, sensors, LCD screen, RF module, Real-Time Clock, etc.

I2C Communication in STM32

The Nucleo boards provide one or more I2C interfaces that can be quickly configured with STCube Tool.

There are four modes of operation:

1. Slave Transmitter
2. Slave Receiver
3. Master Transmitter
4. Master Receiver

The first two are used to operate in slave mode, while the last two are in master mode. By default, the interface is configurated in slave mode.

By default, the I2C interface operates in Slave mode, but it is possible to switch to Master mode to send a Start condition message. Furthermore, it needs to write in I2C_CR2 register the correct clock configuration to generate the expected timings.  The Master sends a Stop condition when the last data byte is transferred, and the interface generates an interrupt.

I2C Packet Message

In general, the packet message is as follow:

• Start condition: the master pulls SDA low and SCL is High to inform slave devices that a transmission is ready to start.
• Address frame: the master sends the address of the slave, each device has an address of 7-10bit, then sends the Read (R) or Write (W) bit, which are respectively 1 and 0. Finally, the master waits that the slave sends the Acknowledge bit (ACK).
• Data frame(s): Send (master) / Receive (slave) Data Byte (DATA) and then Waiting (master) / sending (slave) the Acknowledge bit (ACK)
• Stop condition: the master sends the stop conditions pull SDA to High defined by a low while SCL remains high.

I2C Modes in STM32

Furthermore, there are three ways to exchange data, named:

1. Polling Mode
2. Interrupt Mode

STM32 I2C Polling Mode

• In polling mode, also called blocking mode, the application waits for the data transmission and reception.
• This is a simple way to communicate between devices when the bit rate is not very low, for example when we can debug the board and we want to display the result on screen console.

HAL library provides the following functions to transmit and receive in polling mode:

I2C Master Reciever

• The function to receive data in master mode is as follows:

HAL_I2C_Master_Receive(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)

The parameters are:

• hi2c is a pointer to an I2C_HandleTypeDef structure that contains the configuration information for the specified I2C.
• DevAddress is device address: The device 7 bits address value in the datasheet must be shifted to the left before calling the interface.
• pData is a pointer to data buffer.
• Size is the amount of data to be sent.
• Timeout is the timeout duration.

I2C Master Transmitter

• Master transmits in master mode an amount of data in blocking mode.

HAL_I2C_Master_Transmit(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)

I2C Slave Reciever

• The function to receive data in slave mode is as follows:

HAL_I2C_Slave_Receive(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)

I2C Slave Transmitter

• The function to transmit data in slave mode is as follows:

HAL_I2C_Slave_Transmit(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)

I2C Memory Read

• Master reads an amount of data in blocking mode from a specific memory address.

HAL_I2C_Mem_Read(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)

The additional parameters are:

• MemAddress is the internal device address.
• MemAddSize is the size of the internal device address.

I2C Memory Write

• Master reads an amount of data in blocking mode from a specific memory address.

HAL_I2C_Mem_Write(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size, uint32_t Timeout)

STM32 I2C Interrupt Mode

• In interrupt mode, also called non-blocking mode, in this way the application waits for the end of transmission or reception.
• It is used when the transmission is not used continuously with respect to the activity of the microcontroller.

HAL library provides the following functions to transmit and receive in interrupt mode:

HAL_I2C_Master_Receive_IT(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Master receives in master mode an amount of data in non-blocking mode with interrupt.

HAL_I2C_Master_Transmit_IT(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Master transmits in master mode an amount of data in non-blocking mode with interrupt.

HAL_I2C_Slave_Receive_IT(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Slave receives in master mode an amount of data in non-blocking mode with interrupt.

HAL_I2C_Slave_Transmit_IT(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Slave transmits in master mode an amount of data in non-blocking mode with interrupt.

STM32 I2C DMA Mode

• DMA mode is the best way the exchange data, especially when we want to exchange data quickly and continuously that often require access to memory.

HAL library provides the following functions to transmit and receive in DMA mode:

HAL_I2C_Master_Receive_DMA(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Master receives in master mode an amount of data in non-blocking mode with DMA.

HAL_I2C_Master_Transmit_DMA(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Master transmits in master mode an amount of data in non-blocking mode with DMA.

HAL_I2C_Slave_Receive_DMA(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Slave receives in master mode an amount of data in non-blocking mode with DMA.

HAL_I2C_Slave_Transmit_DMA(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint8_t *pData, uint16_t Size)

Slave transmits in master mode an amount of data in non-blocking mode with DMA. In the STCube tool, the I2C can be configurated fastly and easily as follow.

In Pinout & Configuration, widow selects Connectivity and selects one of the available I2C (I2C1, I2C2, etc). In parameter settings, the master and slave features can be set. Master features are I2C speed mode (standard mode by default and fast mode) and the I2C clock speed (Hz). In standard mode, the device can send up to 400kbit/s while in fast mode up to 1Mbit/s. In general, like clock speed, the STM32 supports 100kHz, 400kHz and sometimes 1MHz.

The main feature of slaves is the primary address length that in general, as previously said, is 7-Bit. Furthermore, the slave can have a secondary address.

Then need to configure the GPIO, as follow:

Now the I2C configuration is terminated and can be possible to generate the code initialization and finally be ready to write our application.

Solenoid Valve: How They Work

In several domestic, commercial, or industrial settings where gases or liquids have to be distributed or mixed, solenoid valves are used to ensure the accuracy and precision of all the control aspects. To help you understand the types and working principles of solenoid valves, selection criteria, and everything in between, we’ve covered all you need to know about these electrically controlled valves. You should also have a look at the Linear Solenoid.

What are Solenoid Valves and How Do They Work?

Solenoid valves are electromechanical devices that feature two major components: a valve body (G) and a solenoid (Figure 1). The solenoid is an electric coil (A) with a movable magnetic core that’s centrally located, also called a plunger (E). It’s also made up of an armature (B), a shading ring (C), a spring (D), and a seal (F).

For a normally closed valve in the resting position, the plunger closes a small hole or orifice that allows the fluid to flow. As soon as the electric current passes through the coil, it’s energized, and an electromagnetic field forms and exerts a force on the plunger, opening the orifice.

That said, it’s worth noting that solenoid valves are only used to control clean liquid and gases. This is because dirt can easily block the orifice, causing performance issues.

Types of Solenoid Valves

Before we look at the working principles of solenoids, we’ll first look at the two popular solenoid valve configurations. These are the normally closed (NC) and the normally open (NO) solenoid valves.

For NC solenoid valves, it is closed when the coil is de-energized, i.e., when there’s no electric current flowing through it. This means that the orifice is closed, and no medium can flow through it. Once the solenoid is powered, the current flows through the coil and energizes it. This creates an electromagnetic field with a resultant force that pushes the plunger upwards to overcome the resistive spring force. This opens up the orifice and allows the fluid media to flow through the valve. NC valves are good for fail-safe applications that need the media to stop flowing if power is lost.

With NO solenoid valves, the valve is always open when the coil is de-energized. Once an electric current passes through the coil, an electromagnetic field is created, and the resultant force pushes the plunger to the downward position to overcome the resistive spring force. Here, the seal will be seated right on the orifice, closing it and preventing any fluid from flowing via the valve. Often, a NO solenoid is best used for applications, which require the solenoid valve to be on or open for a longer period since it becomes more energy and cost-efficient.

Besides the normally closed and normally open solenoids, there’s also another type called the latching or bi-stable solenoid valve. Unlike the previous two, this type is switched on and off using an instantaneous or momentary power source. The solenoid will stay in its recent/current position provided there’s no power supplied. This is accomplished by replacing a spring with permanent magnets.

Working Principles of Solenoid Valves 

There are three main ways in which solenoids work. These are:

Direct-acting

A direct-acting solenoid can either be NO or NC, and its mode of operation is simple. The maximum flow rate and operating pressure are directly proportional to the hole size (diameter) and the solenoid valve’s magnetic force. With this operating principle, the solenoid doesn’t require a minimum pressure or any pressure difference. Direct-acting solenoids are therefore used for small flow rates.

Indirect-acting, Pilot-operated or Servo

Solenoid valves in this category use the pressure difference of the medium to assist in the opening and closing of the valve. The typical minimum pressure required for the valve to operate is nearly 0.5 bar.

In between the outlet and inlet ports is a rubber layer called a diaphragm, which has an orifice through which the fluid medium can easily flow.

Above the membrane is a pressure chamber that serves as an amplifier. This chamber allows a smaller solenoid valve to control a larger flow rate. They are used in industrial or domestic applications that require a higher flow rate and enough pressure differential.

Semi-direct Acting 

With this type of solenoid valve, you enjoy the benefits of both direct-acting and indirect-acting valve operations. Semi-direct acting solenoids operate at zero bar for low flow rate applications and also at pressure differential for high flow rate applications.

Solenoid valves with this working principle have a construction similar to the indirect operating valves except that it has two holes on either side of the membrane, and the plunger is connected directly to the rubber layer. That way, when the electromagnetic force pushes the plunger, the membrane is lifted, opening the valve.

Simultaneously, the second hole is opened if the plunger has a larger diameter compared to the first hole in the rubber membrane. The result is that the pressure inside the chamber above the rubber layer will drop. Hence the membrane isn’t lifted just by the solenoid plunger but also the differential pressure.

Solenoid Valve Use Cases and Approvals  

Solenoids are used in industrial, commercial, and domestic applications to close, open, mix or divert fluid medium. Common domestic applications of solenoids include irrigation systems with automatic control and refrigeration systems to control refrigerants.

Other domestic use cases include air conditioning systems to control air pressure, washing machines and dishwashers to control water flow, and water tanks to control the inflow/outflow of water. In commercial settings, solenoid valves find applications in car washes to control soap and water flow.

And since solenoid valves find different applications in various industries, they must have certain approvals to ensure they conform to industry standards and regulations. Some of the common approvals include:

 

• UL/UR – this is the popular Underwriters Laboratory certification focused on the safety of the solenoid valves.
• Drinking water – there are several approvals that solenoid valves must meet to control water flow used for drinking purposes. Common approvals include the FDA, Kiwa (i.e., a drinking-water approval in the Dutch market), and KTW, which approves plastic and non-metallic consumer materials in Germany.
• CE certification – shows conformity with environmental protection and health requirements for consumer products within the EU economic region.
• ATEX certification – this is an approval for explosion protection.
• IP rating – determines the valve’s protection against dust and water.

Choosing a Solenoid Valve

Now that you know what a solenoid valve is, the types, working principles, use cases, and approvals, what follows is to choose the right type for the right applications. When choosing solenoids, you always want to pay attention to the specific applications and the environment in which they will be installed. From here, you can pay attention to the housing material, the seal material, and the degree of protection as far as temperature and pressure considerations are concerned. Other factors to consider are the operation type, valve function, i.e., whether NO or NC, the voltage type (DC or AC), and the solenoid’s response time.