#include <LiquidCrystal_I2C.h>

#include <Wire.h> 

LiquidCrystal_I2C lcd(0x23, 16, 2);

int trigger=12;
int echo=11;
int timp;
int distanta;

int red=2;
int yellow=3;
int green=4;

int butonPin=6;
int butonNew=0;
int butonOld=0;
int state=0;
int valbuton;

int dist3=20;
int dist2=10;
int dist1=3;

int buzzer=8;
int buzzeralim=A0;
void setup() {
  pinMode(trigger,OUTPUT);
  pinMode(echo,INPUT);
  pinMode(red,OUTPUT);
  pinMode(yellow,OUTPUT);
  pinMode(green,OUTPUT);

  pinMode(butonPin,INPUT);
  pinMode(buzzer, OUTPUT);
  Serial.begin(9600);

  lcd.begin();

  lcd.backlight();
  lcd.print("Initializare");
}

void loop() {
  butonstate();
  Serial.println(distanta);
  leduri(distanta, dist3, dist2, dist1);
  afisare();
  
  
}

void afisare(){
  lcd.clear();
  lcd.print("Distanta:");
  lcd.setCursor(9,0);
  lcd.print(distanta);
  lcd.setCursor(13,0);
  if (state==0){
    lcd.print("cm");
  }
  else{
    lcd.print("in");
  }
  delay(300);
}

int senzor(){
  digitalWrite(trigger,LOW);
  delayMicroseconds(10);
  digitalWrite(trigger,HIGH);
  delayMicroseconds(10);
  digitalWrite(trigger,LOW);
  timp=pulseIn(echo,HIGH);
  delay(25);
  if (state == 0) {
    return 0.0173*timp;
  } else {
    return 0.0173 * timp /2.54;
  }
}

void leduri(int distanta, int dist3, int dist2, int dist1){ 
  if(distanta>dist3){
     digitalWrite(green,HIGH);
     delay(300);
     digitalWrite(green,LOW);
     delay(300);
  }
  else if(distanta>dist2){
    //digitalWrite(buzzer,HIGH);
     digitalWrite(yellow,HIGH);
     delay(300);
     digitalWrite(yellow,LOW);
     delay(300);
  }
  else if(distanta>dist1){
     digitalWrite(red,HIGH);
     delay(300);
     digitalWrite(red,LOW);
     delay(300);
     analogWrite(buzzeralim,150);
     digitalWrite(buzzer, LOW);
     tone(buzzer, 450);
     delay(100);
     noTone(buzzer);
     digitalWrite(buzzer,HIGH);
  }
  else{
    digitalWrite(buzzer,HIGH);
    digitalWrite(green,LOW);
    digitalWrite(yellow,LOW);
    digitalWrite(red,LOW);
  }
}

void butonstate(){
  butonNew=digitalRead(butonPin);
  distanta = senzor();
    if (butonOld==0 && butonNew==1){
      if(state==0){
        state=1;
        dist3=20/ 2.54;
        dist2=10/ 2.54;
        dist1=3/ 2.54;
      }
      else{
        state=0;
        dist3=20;
        dist2=10;
        dist1=3;
      }
    }
    butonOld=butonNew;
    
}