//SLAVE UNO
#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// I2C bus - slave
#include <Wire.h>

// Distance sensor
long cm;

// Reed sensor
int digitalPin = 12;
int digitalVal;

// define the Buzzer pin
int buzzer = 13;

//IR sensor
#define irPin 2
#define led 3

// I2C bus
#define SDA_PIN 4
#define SCL_PIN 5
const int16_t I2C_MASTER = 0x42;
const int16_t I2C_SLAVE = 0x08;


void setup() {

  // I2C setup
  Wire.begin(SDA_PIN, SCL_PIN, I2C_SLAVE);
  Wire.onReceive(receiveEvent);

  //LCD setup
  lcd.begin(16, 2);
  lcd.print(" ");

  //Magnetic sensor setup
  pinMode(digitalPin, INPUT);
  pinMode(buzzer, OUTPUT);

  //IR sensor setup
  pinMode(irPin, INPUT);
  pinMode(led, OUTPUT);

  Serial.begin(9600);

}


void loop() {

  // Magnetic field measuring


  if (digitalRead(digitalPin)) // if magnetic field is detected
    digitalWrite(buzzer, HIGH); // turn ON Buzzer

  else
    digitalWrite(buzzer, LOW); // turn OFF Buzzer


  /*
    digitalVal = digitalRead(digitalPin);
    if (digitalVal == HIGH) // if magnetic field is detected
    {
    digitalWrite(buzzer, HIGH); // turn ON Buzzer
    }
    else
    {
    digitalWrite(buzzer, LOW); // turn OFF Buzzer
    }
  */

  Serial.println(digitalVal);

  delay(20);


  //IR sensor measuring

  if (digitalRead(irPin) == 0)
    digitalWrite(led, HIGH);

  else
    digitalWrite(led, LOW);

/*


  if (digitalRead(irPin) == 0)
  {
    digitalWrite(led, HIGH);
  }
  else {
    digitalWrite(led, LOW);
  }
*/
}


void receiveEvent(size_t howMany) {

  (void) howMany;

  long duration = Wire.read();    // receive byte

  // Distance writing

  cm = float(duration / 2) * 0.0343;

  lcd.print("Distance");

  lcd.setCursor(0, 1);
  lcd.print(cm);

  lcd.setCursor(7, 1);
  lcd.print("cm");

  delay(100);

  lcd.clear();

}