#include <Wire.h>

#define led 4
#define button 0

int buttonState;

void setup() {
  pinMode(led, OUTPUT);
  pinMode(button, INPUT_PULLUP);

  Serial.begin(115200);
  Wire.begin(1); //address for node1 is 1
  
  //onRequest is responding to requestFrom function from the control
  Wire.onRequest(requestEvent);
}

void loop() {
  //if button on node is pressed, turn on the led and give the buttonState varible 5
  if(digitalRead(button) == LOW){
    digitalWrite(led, HIGH);
    delay(200);
    digitalWrite(led, LOW);
    buttonState = 5;
  }
  else{
    buttonState = 0;
  }
}

//send data from node to the control
void requestEvent(){
  Wire.write(buttonState);
}