#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

int relayPin1 = 2; // red
int relayPin2 = 3; // green
int relayPin3 = 4; // blue
int relayPin4 = 5; // white

int inches = 0;
int cm = 0;

int resetButton = 8;
int buzzer = 9;

long readUltrasonicDistance(int trigPin, int echoPin)
{
  pinMode(trigPin, OUTPUT);
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  pinMode(echoPin, INPUT);
  return pulseIn(echoPin, HIGH);
}

void setup() {
  pinMode(relayPin1, OUTPUT);
  pinMode(relayPin2, OUTPUT);
  pinMode(relayPin3, OUTPUT);
  pinMode(relayPin4, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(resetButton, INPUT);

  Serial.begin(115200);

  lcd.init();
  lcd.backlight();
}

void loop() {
  //int btnState = digitalRead(resetButton);
  if(digitalRead(resetButton) == HIGH)
  {
    digitalWrite(relayPin1, LOW);
    digitalWrite(relayPin2, LOW);
    digitalWrite(relayPin3, LOW);
    digitalWrite(relayPin4, LOW);

    Serial.flush();
    for(int i=10; i<=0; i--)
    {
      Serial.print("Resetting..." + i);
      Serial.flush();
      delay(1000);
    }
  }

  else
  {
    cm = 0.01723 * readUltrasonicDistance(6, 7);

    inches = (cm / 2.54);
    Serial.print(inches);
    Serial.print(" in, ");
    Serial.print(cm);
    Serial.println(" cm");
    delay(100);

    if (cm >= 5 && cm < 10)
    {
      digitalWrite(relayPin1, LOW);
      digitalWrite(relayPin2, LOW);
      digitalWrite(relayPin3, LOW);
      digitalWrite(relayPin4, HIGH);
    }
    else if (cm >= 10 && cm < 15)
    {
      digitalWrite(relayPin1, LOW);
      digitalWrite(relayPin2, LOW);
      digitalWrite(relayPin3, HIGH);
      digitalWrite(relayPin4, LOW);
    }
    else if (cm >= 15 && cm < 20)
    {
      digitalWrite(relayPin1, LOW);
      digitalWrite(relayPin2, HIGH);
      digitalWrite(relayPin3, LOW);
      digitalWrite(relayPin4, LOW);
    }
    else if (cm >= 20 && cm < 30)
    {
      digitalWrite(relayPin1, HIGH);
      digitalWrite(relayPin2, LOW);
      digitalWrite(relayPin3, LOW);
      digitalWrite(relayPin4, LOW);

        tone(buzzer, 50);
        delay(100);
        noTone(buzzer);
    }
    else if (cm >= 30)
    {
      digitalWrite(relayPin1, LOW);
      digitalWrite(relayPin2, LOW);
      digitalWrite(relayPin3, LOW);
      digitalWrite(relayPin4, LOW);
    }
  }
}