i2c.ino

#include <Wire.h>
 
#define SLAVE_ADDRESS 0x04
int number = 0;
int state = 0;
 
double temp;
double temp2;
 
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);
 temp = GetTemp();
 temp2 = Thermistor( analogRead( 0 ));
}
 
// 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)temp;
  }if(number==4) {
   number = (int)temp2;
  }
 }
}
 
// callback for sending data
void sendData(){
 Wire.write(number);
}
 
// Get the internal temperature of the arduino
double GetTemp(void)
{
 unsigned int wADC;
 double t;
 ADMUX = (_BV(REFS1) | _BV(REFS0) | _BV(MUX3));
 ADCSRA |= _BV(ADEN); // enable the ADC
 delay(20); // wait for voltages to become stable.
 ADCSRA |= _BV(ADSC); // Start the ADC
 while (bit_is_set(ADCSRA,ADSC));
 wADC = ADCW;
 t = (wADC - 324.31 ) / 1.22;
 return (t);
}
double Thermistor(int RawADC) {
  double Temp;
  Temp = log(10000.0*((1024.0/RawADC-1))); 
//         =log(10000.0/(1024.0/RawADC-1)) // for pull-up configuration
  Temp = 1 / (0.001129148 + (0.000234125 + (0.0000000876741 * Temp * Temp ))* Temp );
  Temp = Temp - 273.15;            // Convert Kelvin to Celcius
// Temp = (Temp * 9.0)/ 5.0 + 32.0; // Convert Celcius to Fahrenheit
  return Temp;
}