Connecting Ardunio micro and Arduino UNO thorugh I2C protocol

Projects Programming
1

Hello.
I'm facing a problem with connecting Arduino UNO (as slave) and Ardunio micro (as master). I've connected their grounds together, pins A4 together and pins A5 together. I've run the below codes but although I'm assigning x a value of 5, I'm getting the word linked with x==0 which is "Hello" instead of "Hello5". I would appreciate your help, please.

master's code

#include <Wire.h>
int x = 0;
void setup() {
// Start the I2C Bus as Master
Wire.begin();
Serial.begin(9600);
}
void loop() {
Wire.beginTransmission(9); // transmit to device #9
Wire.write(x); // sends x
Wire.endTransmission(); // stop transmitting
x = 5;
Serial.println(x);
//x++; // Increment x
// if (x > 5) x = 0; // `reset x once it gets 6
// delay(500);
}

Salve's code
#include <Wire.h>
int LED = 13;
int x = 0;
void setup() {
// Define the LED pin as Output
pinMode (LED, OUTPUT);
// Start the I2C Bus as Slave on address 9
Wire.begin(9);
// Attach a function to trigger when something is received.
Wire.onReceive(receiveEvent);
Serial.begin(9600);

}
void receiveEvent(int bytes) {
x = Wire.read(); // read one character from the I2C
}
void loop() {
//If value received is 0 blink LED for 200 ms
if (x == 0) {
Serial.println("Hello");
}
//If value received is 3 blink LED for 400 ms
if (x == 1) {
Serial.println("Hello again");
if (x == 2) {
Serial.println("Hello2");
}
if (x == 3) {
Serial.println("Hello3");
}if (x == 4) {
Serial.println("Hello4");
}if (x == 5) {
Serial.println("Hello5");
}
}
}

2

The I2C pins on a Micro may be different from on an Uno.

...R
Arduino to Arduino I2C Tutorial

3

The problem is in your receiver. You should receive 2 transmissions. The first with a 0 and the second with a 5. Assuming you receive the transmissions, look at your if statements with this properly formatted code and you'll see why Hello5 is never printed:

#include <Wire.h>
int LED = 13;
int x = 0;
void setup() {
  // Define the LED pin as Output
  pinMode (LED, OUTPUT);
  // Start the I2C Bus as Slave on address 9
  Wire.begin(9);
  // Attach a function to trigger when something is received.
  Wire.onReceive(receiveEvent);
  Serial.begin(9600);

}
void receiveEvent(int bytes) {
  x = Wire.read();    // read one character from the I2C
}
void loop() {
  //If value received is 0 blink LED for 200 ms
  if (x == 0) {
    Serial.println("Hello");
  }
  //If value received is 3 blink LED for 400 ms
  if (x == 1) {
    Serial.println("Hello again");
    if (x == 2) {
      Serial.println("Hello2");
    }
    if (x == 3) {
      Serial.println("Hello3");
    } if (x == 4) {
      Serial.println("Hello4");
    } if (x == 5) {
      Serial.println("Hello5");
    }
  }
}