Serial Communication Between Two Microcontrollers

1. Required Components

• 2 x Arduino Boards (e.g., Arduino Uno)
• Jumper Wires
• USB Cables for each Arduino

2. Connection Setup

Follow these steps to set up the wiring between two Arduino boards:

• Connect the TX pin of Arduino 1 to the RX pin of Arduino 2.
• Connect the RX pin of Arduino 1 to the TX pin of Arduino 2.
• Connect the GND (ground) pins of both Arduinos together.

Note: Keep both boards connected to your computer via USB to power them and upload code.

3. Arduino Code for Sender (Arduino 1)

The following code sends data from Arduino 1 to Arduino 2:

// Sender Code for Arduino 1

void setup() {
  // Initialize serial communication at 9600 baud
  Serial.begin(9600);
}

void loop() {
  // Send a message to the other Arduino
  Serial.println("Hello from Arduino 1");
  
  // Delay for 1 second before sending the next message
  delay(1000);
}
            

4. Arduino Code for Receiver (Arduino 2)

The following code receives and displays the data from Arduino 1:

// Receiver Code for Arduino 2

void setup() {
  // Initialize serial communication at 9600 baud
  Serial.begin(9600);
}

void loop() {
  // Check if data is available to read
  if (Serial.available() > 0) {
    // Read the incoming data
    String receivedMessage = Serial.readString();
    
    // Display the received data on the Serial Monitor
    Serial.print("Received: ");
    Serial.println(receivedMessage);
  }
}
            

5. Steps to Upload and Test

1. Connect both Arduino boards to your computer using USB cables.
2. Upload the sender code to Arduino 1.
3. Upload the receiver code to Arduino 2.
4. Open the Serial Monitor in the Arduino IDE for Arduino 2 to view the received data.
5. You should see the message "Hello from Arduino 1" printed every second in Arduino 2's Serial Monitor.

6. Additional Tips

• Common Ground: Ensure the ground pins are connected to avoid communication errors.
• Expandability: Modify the code to send sensor readings or control signals between boards.
• Debugging: Use LEDs or additional Serial prints to troubleshoot issues in the wiring or code.

7. Conclusion

Congratulations! You've successfully implemented serial communication between two Arduino boards using UART. This foundational technique is essential for building interconnected systems in robotics, data logging, and IoT projects.