// Constants for LDR
#define MAX_ADC_READING 4095
#define ADC_REF_VOLTAGE 3.3
#define REF_RESISTANCE 5030
#define LUX_CALC_SCALAR 12518931
#define LUX_CALC_EXPONENT -1.405
#define BLYNK_TEMPLATE_ID "TMPL6liFFNBKM"
#define BLYNK_TEMPLATE_NAME "micro sd"
#define BLYNK_AUTH_TOKEN "ftxo20eoYwm-tnB-_opwmVRq_Wm3pE7y"

// Libraries
#define BLYNK_PRINT Serial
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>

// Blynk Auth Token
char ssid[] = "Wokwi-GUEST";             // ใส่ชื่อ Wi-Fi
char pass[] = "";         // ใส่รหัสผ่าน Wi-Fi

// Pin Definitions
const int LDR_PIN = 35;          // LDR sensor pin
const int pingPin = 18;          // Ultrasonic Trigger
const int echoPin = 19;          // Ultrasonic Echo
const int buzzer = 26;           // Buzzer pin
const int relayPin = 27;         // Relay pin


// Variables
float ldrLux = 0;
long duration, cm;

// Timer
BlynkTimer timer;

void setup() {
  Serial.begin(115200);
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);  // ใช้ BLYNK_AUTH_TOKEN

  // Pin Modes
  pinMode(pingPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(relayPin, OUTPUT);

  // Timer for sending data to Blynk
  timer.setInterval(1000L, sendSensorData); // Update every 1 second
}

void loop() {
  Blynk.run();
  timer.run();
}

// Function: Send Ultrasonic and LDR Data
void sendSensorData() {
  // --- Read Ultrasonic Sensor ---
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(pingPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  cm = duration / 29 / 2;

  // --- Read LDR Sensor ---
  int ldrRawData = analogRead(LDR_PIN);
  float resistorVoltage = (float)ldrRawData / MAX_ADC_READING * ADC_REF_VOLTAGE;
  float ldrVoltage = ADC_REF_VOLTAGE - resistorVoltage;
  float ldrResistance = (resistorVoltage > 0) ? (ldrVoltage / resistorVoltage * REF_RESISTANCE) : 0;
  ldrLux = LUX_CALC_SCALAR * pow(ldrResistance, LUX_CALC_EXPONENT);

  // --- Send Data to Blynk Dashboard ---
  Blynk.virtualWrite(V0, cm);        // Ultrasonic distance on V0
  Blynk.virtualWrite(V1, ldrLux);    // LDR Lux value on V1

  // --- Condition 1: Ultrasonic < 5 cm ---
  if (cm <= 5) {
    for (int i = 0; i < 2; i++) {     // Beep twice
      digitalWrite(buzzer, HIGH);
      delay(200);
      digitalWrite(buzzer, LOW);
      delay(200);
    }
    Blynk.virtualWrite(V2, 255);      // LED1 ON at V2
  } else {
    Blynk.virtualWrite(V2, 0);        // LED1 OFF
  }

  // --- Condition 2: LDR Lux < 300 ---
  if (ldrLux < 300) {
    digitalWrite(relayPin, HIGH);     // Relay ON
    Blynk.virtualWrite(V3, 255);      // LED2 ON at V3
  } else {
    digitalWrite(relayPin, LOW);      // Relay OFF
    Blynk.virtualWrite(V3, 0);        // LED2 OFF
  }

  // Serial Monitor Debugging
  Serial.print("Distance: ");
  Serial.print(cm);
  Serial.println(" cm");

  Serial.print("LDR Lux: ");
  Serial.print(ldrLux);
  Serial.println(" lux");
}