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

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27, 16 columns and 2 rows

const int potPin = A0;
const int trigPin = 9;
const int echoPin = 10;
const int stepperStepPin = 2;
const int stepperDirPin = 3;
const int stepperEnablePin = 4;
const int buzzerPin = 5;
const int distanceThreshold = 30;  // Distance threshold in centimeters

int speed;
float distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(stepperStepPin, OUTPUT);
  pinMode(stepperDirPin, OUTPUT);
  pinMode(stepperEnablePin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  
  lcd.begin(16, 2);  // initialize the LCD 
  lcd.print("Speed: ");
}

void loop() {
  // Read the potentiometer value to control speed
  speed = analogRead(potPin) / 4; // map the pot value (0-1023) to speed (0-255)
  
  // Control the stepper motor speed
  digitalWrite(stepperDirPin, HIGH); // Set the direction
  for (int i = 0; i < speed; i++) {
    digitalWrite(stepperStepPin, HIGH);
    delayMicroseconds(500);
    digitalWrite(stepperStepPin, LOW);
    delayMicroseconds(500);
  }

  // Ultrasonic sensor to detect distance
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  distance = pulseIn(echoPin, HIGH) * 0.034 / 2;

  // Display speed on LCD
  lcd.setCursor(7, 0);
  lcd.print("    "); // Clear previous speed value
  lcd.setCursor(7, 0);
  lcd.print(speed);

  // Check for over-speed and trigger warning
  if (speed > 120) {
    lcd.setCursor(0, 1);
    lcd.print("Over Speed!");
    digitalWrite(buzzerPin, HIGH);
  } else if (distance <= distanceThreshold) {
    lcd.setCursor(0, 1);
    lcd.print("Collision Detected!");
    digitalWrite(buzzerPin, HIGH);
  } else {
    lcd.setCursor(0, 1);
    lcd.print("In Safe Distance"); // Clear warning message
    digitalWrite(buzzerPin, LOW);
  }

  delay(100); // Adjust delay based on the system response time
}