#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <NewPing.h>
#include <WiFi.h>
#define BLYNK_TEMPLATE_ID "TMPL38fsTl87n"
#define BLYNK_TEMPLATE_NAME "Vehicle Detector"
#define BLYNK_AUTH_TOKEN "ktOQrfnf-7oBQm1juPPWy8672ku4yq6V"
#include <BlynkSimpleEsp32.h>

// Ultrasonic Sensor Pins
#define TRIGGER_PIN 4
#define ECHO_PIN 16
#define MAX_DISTANCE 400 

// Buzzer Pin
#define BUZZER_PIN 17

// Potentiometer Pin
#define POTENTIOMETER_PIN 34

// I2C LCD Address and Dimensions
#define I2C_ADDR 0x27 
#define LCD_COLUMNS 16
#define LCD_ROWS 2

// Blynk Credentials
char auth[] = BLYNK_AUTH_TOKEN; 
char ssid[] = "Wokwi-GUEST"; 
char pass[] = ""; 

// Initialize LCD
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_ROWS);

// Initialize Ultrasonic Sensor
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

unsigned long lastTime = 0;
float lastDistance = 0;

void setup() {
  // Initialize Serial Monitor
  Serial.begin(115200);

  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Initialize Buzzer Pin
  pinMode(BUZZER_PIN, OUTPUT);

  // Initialize Blynk
  Blynk.begin(auth, ssid, pass);

  // Display startup message on LCD
  lcd.setCursor(0, 0);
  lcd.print("Radar Started");
  delay(100);
  lcd.clear();
}

void loop() {
  Blynk.run();

  // Read potentiometer value
  int potValue = analogRead(POTENTIOMETER_PIN);
  int contrast = map(potValue, 0, 4095, 0, 255); // Map to a suitable range for contrast control

  // Apply contrast value (dummy function for demonstration purposes, 
  // actual contrast control depends on specific LCD used)
  //analogWrite(3.3V, contrast);

  // Measure distance
  float distance = sonar.ping_cm() / 100.0; // Convert to meters

  // Calculate speed
  unsigned long currentTime = millis();
  float speed = 0;

  if (lastTime != 0) {
    unsigned long timeDiff = currentTime - lastTime; // Time difference in ms
    float distanceDiff = distance - lastDistance; // Distance difference in meters
    speed = (distanceDiff * 1000) / timeDiff; // Speed in m/s
  }

  lastTime = currentTime;
  lastDistance = distance;

  // Display on LCD
  lcd.setCursor(0, 0);
  lcd.print("Dist: ");
  lcd.print(distance, 2);
  lcd.print("m");

  lcd.setCursor(0, 1);
  lcd.print("Speed: ");
  lcd.print(speed, 2);
  lcd.print("m/s");

  // Send data to Blynk
  Blynk.virtualWrite(V1, distance); // Virtual pin V1 for distance
  Blynk.virtualWrite(V2, speed); // Virtual pin V2 for speed

  // Trigger Buzzer if condition met
  if (distance < 0.05 || speed > 10) {
    digitalWrite(BUZZER_PIN, HIGH);
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }

  delay(100); // Wait 100ms before next measurement
}