#include <Wire.h>

const int ledPin2 =  2;
const int slave_address =  0x01;
byte x = 1;
byte estado = 0;

void setup() {
  // Initialize Serial port
  Serial.begin(9600);
  Serial.println();
  Serial.println(F("--------------------------------"));
  Serial.println(F("Networking and Communications (MASTER)"));
  Serial.println(F("--------------------------------"));

  Wire.begin(); // join i2c bus (address optional for master)
  //pinMode(ledPin2, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
  //Transmition
  Wire.beginTransmission(1); // transmit to device #1
  Wire.write(6);              // sends one byte  
  // Enviamos un byte, L pondrá en estado bajo y H en estado alto
  Wire.write(estado);
  if(Wire.endTransmission() != 0){    // stop transmitting
    Serial.print("ERROR de comm");
  }
  else if(Wire.endTransmission() == 0){
    Serial.print("Sent!");
    digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
    delay(1000);
  }
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW

  // Cambiamos el estado
  if (estado == 0)
  {
    estado = 1;
  }
  else
  {
    estado = 0;
  }

  //Reception
  /*Wire.requestFrom(slave_address, 1);    // request 6 bytes from slave device #8
  while (Wire.available()) { // slave may send less than requested
    char c = Wire.read(); // receive a byte as character
    Serial.print(c);         // print the character
  }*/
  
}