Using I2C as Communication Link between Arduinos 2012010401

2012010401.c

#include <Wire.h>

// preparing for which slave device
// need to be connected
int slaveId = 0 ;

void setup() {
  Serial.begin( 9600 ) ;
  while ( !Serial ) ; 
  // Run as I2C Master
  Wire.begin() ;
}

void loop() {
  if ( Serial.available() ) {
   
    // console terminal read per character
    char ch = Serial.read() ;
    // map key '1' for slave device id #1
    // map key '2' for slave device id #2
    switch ( ch ) {
    case '1' :
      slaveId = 1 ;
      Serial.println( " > connected to slave id #1" ) ;
      return ;
    case '2' :
      slaveId = 2 ;
      Serial.println( " > connected to slave id #2" ) ;
      return ;
    }
   
    // try to send the character to
    // the specific slave id
    if ( slaveId > 0 ) {
      Wire.beginTransmission( slaveId ) ;
      Wire.write( ch ) ;
      Wire.endTransmission() ;
    }
   
  }
}