// Muhammad Rusman Hilmi Bin Mohd Rais
// Lab L01-B02

#include <LiquidCrystal_I2C.h>
#include <Wire.h>

#define trigerPin 12
#define echoPin 13
#define ledPin 2
#define buzzerpin 10
#define pitch 262
#define led  7
#define button  6
int knob = 0;

LiquidCrystal_I2C lcd(0x27,16,2);

double duration;
int distance;

void setup() {
 
  Serial.begin(9600);
  pinMode(trigerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerpin, OUTPUT);
  pinMode(led, OUTPUT); 
  lcd.init(); 
  lcd.backlight(); 
  lcd.setCursor(0,0); 
  lcd.print("Danger Detection"); 
  lcd.setCursor(0,1); 
  lcd.print("by rusman"); 
  delay(1000);
}

void loop() {

  lcd.clear(); 
  digitalWrite(trigerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigerPin, LOW);
  delayMicroseconds(2);
 
  duration = pulseIn(echoPin,HIGH);
  distance = (duration/2) * 0.0343;

  lcd.setCursor(0,0);
  lcd.print("Danger: ");
  lcd.print("Ahead");
  delay(1000); 

  if(distance<=200){
    knob = digitalRead(button); 
    if(knob == HIGH) 
      digitalWrite(led, LOW); 
      delay(500);  
      digitalWrite(led, HIGH);     
      delay(200);
      digitalWrite(ledPin, HIGH);
      tone(buzzerpin, pitch);
      delay(300);

      if(knob == LOW){  
      digitalWrite(led, HIGH);   
    }
      digitalWrite(ledPin, LOW);
      noTone(buzzerpin);
      delay(300);
  }
  else{
    digitalWrite(ledPin, LOW);
    noTone(buzzerpin);
  }
   lcd.setCursor(0,1); 
   lcd.print("Ready for impact");delay(1000);
   
   if(distance >200){ 
   digitalWrite(led, LOW);  
   }
}