gistfile1.cpp

#include <Wire.h>
 
#define SLAVE_ADDRESS 0x04
int number = 0;
int state = 0;
 
int moist;
 
void setup() {
 pinMode(13, OUTPUT);
 
 // initialize i2c as slave
 Wire.begin(SLAVE_ADDRESS);
 
 // define callbacks for i2c communication
 Wire.onReceive(receiveData);
 Wire.onRequest(sendData);
}
 
void loop() {
 delay(100);
 moist = GetMoist();
}
 
// callback for received data
void receiveData(int byteCount){
 
 while(Wire.available()) {
  number = Wire.read();
 
  if (number == 1){
   if (state == 0){
    digitalWrite(13, HIGH); // set the LED on
    state = 1;
   } else{
    digitalWrite(13, LOW); // set the LED off
    state = 0;
   }
  }
 
  if(number==2) {
   number = (int)moist;
  }
 }
}
 
// callback for sending data
void sendData(){
 Wire.write(number);
}
 
// Get the internal temperature of the arduino
int GetMoist(void)
{
  return(analogRead(A2));
}