Master writer

This example is for Wiring version 1.0 build 0100+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Wire Slave Receiver by Nicholas Zambetti

Demonstrates use of the Wire library Receives data as an I2C/TWI slave device Refer to the "Wire Master Writer" example for use with this On Wiring v1 boards the SCL and SDA pins are: 0 and 1 On Wiring S board the SCL and SDA pins are: 8 and 9

#include <Wire.h>

void setup()
  Wire.begin(4);                 // join i2c bus with address #4
  Wire.onReceive(receiveEvent);  // register event
  Serial.begin(9600);            // start serial for output

void loop()

// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany)
  while(1 < Wire.available())  // loop through all but the last
    char c =;   // receive byte as a character
    Serial.print(c);           // print the character
  int x =;      // receive byte as an integer
  Serial.println(x);           // print the integer