#include <TinyWireS.h>//include the library
#define I2C_SLAVE_ADDRESS 0x6//define the address for the slave
    
int LED = 7;

void setup()
{
TinyWireS.begin(I2C_SLAVE_ADDRESS); //setup initialization, join as slave

pinMode(LED, OUTPUT);
}

void loop()
{
  byte byteRcvd =0;
  volatile byte msg =0;//treat as variable
  if(TinyWireS.available()){ //if input and slave available
      byteRcvd = TinyWireS.receive(); //receive from master
      
      if (byteRcvd == 0x01){ //if bytes received
      digitalWrite (LED, HIGH); //turn off LED
      TinyWireS.send(4);//send message
    }  
      else {
      digitalWrite (LED, LOW);//turn on LED
      TinyWireS.send(5); //send message
      }
}
}