/*
 * Sources:
 * https://arduinogetstarted.com/tutorials/arduino-button-toggle-led
 * https://arduinogetstarted.com/tutorials/arduino-button-servo-motor
 * https://roboticadiy.com/how-to-use-buzzer-with-ultrasonic-sensor/
 * https://www.arduino.cc/reference/en/libraries/ezbutton/
 */

// include the libraries used
#include <ezButton.h>
#include <Servo.h>

// define constants
const int BUTTON_PINoff   = 2;  // the number of the pushbutton pin
const int BUZZER_PIN      = 4;  // the number of the Buzzer pin
const int BUTTON_PIN      = 7;  // the number of the pushbutton pin
const int LED_PIN         = 8;  // the number of the LED pin
const int SERVO_PIN       = 9;  // the number of the Servo pin
const int ECHO_PIN        = 12; // the number of the Echo pin
const int TRIG_PIN        = 13; // the number of the Trig pin

/// SERVO
Servo servo;  // create servo object
int pos = 0;  // define initial position of servo
/// BUTTON
ezButton button(BUTTON_PIN);        // create ezButton object that attach to pin 7;
ezButton buttonOff(BUTTON_PINoff);  // create ezButton object that attach to pin 7;

// define variables
int ledState = LOW;       // the current state of LED
int angle = 90;           // the current state of Servo
long duration, distance;  // variables for simple distance function

/// INITIALIZATION
void setup() {
  Serial.begin(9600);             // initialize serial
  pinMode(LED_PIN, OUTPUT);       // set arduino pin to output mode
  button.setDebounceTime(10);     // set debounce time to 50 milliseconds
  buttonOff.setDebounceTime(10);  // set debounce time to 50 milliseconds
  servo.attach(SERVO_PIN);        // attach servo to pin 9
  pinMode(TRIG_PIN, OUTPUT);      // set arduino pin to output mode
  pinMode(ECHO_PIN , INPUT);      // set arduino pin to input mode
}

/// MAIN LOOP
void loop() {
  button.loop(); // MUST call the loop() function first
  if(button.isPressed()) 
  {

    // LED - turn on
    ledState = !ledState;
    digitalWrite(LED_PIN, ledState); 
    Serial.println("The light is on");

    // SERVO - open the gate
    angle = 0;
    servo.write(angle);
    Serial.println("The gate is open");

    // Buzzer loop - print outside so only once
    Serial.println("The buzzer is on");
    while(true)
    {
        // setup of the input frequency
        digitalWrite(TRIG_PIN, HIGH);
        //delayMicroseconds(50);
        digitalWrite(TRIG_PIN, LOW);

        duration = pulseIn(ECHO_PIN, HIGH);  // definition of the output
        distance = (duration/2) / 29.1;     // function for the distance - decision parameter

        if (distance < 200 && distance > 10)
        { 
        tone(BUZZER_PIN,500,distance/20);
        //millis(distance/2);
        Serial.println(distance/2);
        }
        else if(distance <=10)
        {
        tone(BUZZER_PIN,500,distance/6);
        //millis(10);
        }
        // no buzzer tone at 390+
        else 
        {
        noTone(BUZZER_PIN);
        }

        buttonOff.loop();
        if(buttonOff.isPressed()) // if the second button is pushed, the while loop stops
          break;
    }
    //Turn off the LED, the buzzer and close the gate
    ledState = !ledState;
    digitalWrite(LED_PIN, ledState);
    Serial.println("The light is off");
    angle = 90;
    servo.write(angle);
    Serial.println("The gate is closed");
    noTone(BUZZER_PIN);
    Serial.println("The buzzer is off");
  }
}