Project 1 - Interfacing a 16*2 LCD with Arduino using I2C protocol

Interfacing a 16x2 LCD with two Arduinos (Master and Slave) using I2C communication protocol:

Master Arduino Code:

1. Include the Wire.h library.
2. Initialize the Wire library with the begin() function.
3. Define the I2C address of the Slave Arduino.
4. In the setup function, begin the serial communication and LCD initialization.
5. In the loop function, read input from the serial monitor and write the message to the I2C bus using the Wire library.

Slave Arduino Code:

1. Include the Wire.h and LiquidCrystal_I2C.h libraries.
2. Initialize the Wire library with the begin() function.
3. In the setup function, begin the serial communication, LCD initialization and set the Slave Arduino I2C address using the Wire library.
4. In the loop function, read data from the I2C bus using the Wire library and display it on the LCD screen using the LiquidCrystal_I2C library.

Here is the sample code for Master and Slave Arduinos:

Master Arduino Code:

#include

#define SLAVE_ADDRESS 0x09 // Slave address

void setup() {
Wire.begin();
Serial.begin(9600);
}

void loop()
{
String message;

// Wait for user to input message
while (Serial.available() == 0)
{
delay(50);
}

// Read user message from Serial
message = Serial.readStringUntil('n');

// Send message to slave Arduino
Wire.beginTransmission(SLAVE_ADDRESS);
Wire.write(message.c_str(),message.length()); // Write the message as a string of bytes
Wire.endTransmission();

// Print sent message on Serial
Serial.print("Sent message: ");
Serial.println(message);

delay(10);
}

Slave Code

#include
#include

#define SLAVE_ADDRESS 0x09

LiquidCrystal_I2C lcd(0x20, 16, 2);

void setup() {
Wire.begin(SLAVE_ADDRESS);
Wire.onReceive(receiveData);
lcd.init();
lcd.backlight();
lcd.setCursor(0,0);
lcd.print("Slave ready");
}

void loop() {
// Do nothing in the main loop
}

void receiveData(int len) {
String message = "";
while (Wire.available()) {
message += (char)Wire.read();
}
lcd.clear();
lcd.setCursor(0,0);
lcd.print(message);
}