// Wire Slave Receiver
// by Nicholas Zambetti <http://www.zambetti.com>

// 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

// Created 29 March 2006

// This example code is in the public domain.


#include <Wire.h>

byte c[4];

void setup() {
  Wire.begin(5);                // join I2C bus with address #8
  //Wire.setClock(100000L);
  Wire.onReceive(receiveEvent); // register event
  Wire.onRequest(requestEvent); // register event
  Serial.begin(9600);           // start serial for output
}

void loop() {
  delay(100);
}

// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany) {
  int i = 0;
  while (Wire.available()) { // loop through all but the last
    c[i] = Wire.read(); // receive byte as a character
    i++;
  }
  Serial.println((int)c);         // print the character
  //int x = Wire.read();    // receive byte as an integer
  //Serial.println(x);         // print the integer
}

void requestEvent() {
  for(int i = 0; i < 4; i++){
    Wire.write(c[i]);
  }
  // as expected by master
}