Arduino Serial Communication Example

Of course, below I will provide a complete example of Arduino serial communication. This example will demonstrate how to perform simple data exchange between Arduino and a computer. We will write a program that receives characters from the computer and performs different actions based on the received characters. At the same time, Arduino will also send feedback to the computer.

Hardware Preparation

– Arduino board (such as Uno, Nano, etc.)

– USB data cable

– Computer

Software Preparation

– A computer with Arduino IDE installed

Project Objective

When the user sends specific characters through the serial monitor, Arduino will perform the following actions based on the characters:

– Send character `’L’` or `’l’`: Turn on the LED.

– Send character `’H’` or `’h’`: Turn off the LED.

– Send any other character: Return “Unknown Command”.

Assuming we use the built-in LED on the Arduino Uno board (connected to pin 13).

Arduino Code

const int ledPin = 13; // Built-in LED connected to pin 13
void setup() {
  // Initialize serial communication at 9600 baud rate
  Serial.begin(9600);
  // Set LED pin as output mode
  pinMode(ledPin, OUTPUT);
}
void loop() {
  // Check if there is data from the serial port
  if (Serial.available() > 0) {
    // Read a byte of data
    char receivedChar = Serial.read();
    // Perform corresponding actions based on the received character
    switch (receivedChar) {
      case 'L':
      case 'l':
        digitalWrite(ledPin, HIGH); // Turn on LED
        Serial.println("LED is ON");
        break;
      case 'H':
      case 'h':
        digitalWrite(ledPin, LOW); // Turn off LED
        Serial.println("LED is OFF");
        break;
      default:
        // If it is another character, return unknown command
        Serial.print("Unknown Command: ");
        Serial.println(receivedChar);
        break;
    }
  }
}

Upload Code

1. Connect the Arduino board to the computer via USB data cable.

2. Open Arduino IDE.

3. Select the correct board and port (Tools -> Board and Tools -> Port).

4. Copy and paste the above code into Arduino IDE.

5. Click the upload button to upload the code to the Arduino board.

Test Communication

1. After uploading, open the serial monitor in Arduino IDE (Tools -> Serial Monitor).

2. In the serial monitor, ensure the baud rate is set to 9600, which should match `Serial.begin(9600)` in the Arduino code.

3. In the input box of the serial monitor, enter character `’L’` or `’l’` and press Enter. You should see the built-in LED light up, and the serial monitor displays “LED is ON”.

4. Enter character `’H’` or `’h’` and press Enter. You should see the built-in LED turn off, and the serial monitor displays “LED is OFF”.

5. Enter any other character, such as `’X’`, and press Enter. You should see “Unknown Command: X” in the serial monitor.

Further Expansion

– Add more features: You can expand this project by adding more control commands to control additional hardware components or implementing more complex logic.

– Two-way communication: In addition to responding to commands from the computer, you can also have Arduino actively send data to the computer, such as sensor readings or status updates.

– Improve reliability: You can introduce a simple protocol to enhance the reliability of communication, such as adding checksums or using fixed command formats.

This simple example demonstrates how to use Arduino for basic serial communication. If you have any questions or need further assistance, feel free to leave a message to discuss!