// Define the pin numbers for the LED and PIR sensor
const int ledpin = 27;           // Pin number for the LED
const int PIRinput = 26;        // Pin number for the PIR sensor

// Variable to store the current state of the PIR sensor
int pirState = LOW;
// Analog input pin for the NTC thermistor
const int NTC_PIN = 25;

// Temperature threshold to trigger the alarm (adjust as needed)
const float TEMPERATURE_THRESHOLD = 30.0;
#define LIGHT_SENSOR_PIN 33 // ESP32 pin GIOP36 (ADC0)


// Setup function: runs once when the device starts up
void setup() {
  // Set the LED pin as an output
  pinMode(ledpin, OUTPUT);
  // Set the PIR sensor pin as an input
  pinMode(PIRinput, INPUT);
  // Begin serial communication at a baud rate of 9600
  Serial.begin(9600);
  pinMode(NTC_PIN, INPUT);

}

// Loop function: runs repeatedly as long as the device is powered on
void loop() {
  // Read the state of the PIR sensor
  const int IP = digitalRead(PIRinput);
  // Delay for stability
  delay(100);
  
  // If motion is detected by the PIR sensor
  if (IP == 1) {
    // Turn on the LED
    digitalWrite(ledpin, HIGH);
    // If this is the first time motion is detected since the last reset
    if (pirState == LOW) {
      // Print "Motion detected!" to the serial monitor
      Serial.println("Motion detected!");
      // Update pirState to indicate motion detection
      pirState = HIGH;
    }
    // Delay for 1 second
    delay(1000);
  } else {
    // If no motion is detected by the PIR sensor
    // Turn off the LED
    digitalWrite(ledpin, LOW);
    // If motion was detected previously
    if (pirState == HIGH) {
      // Print "Motion ended!" to the serial monitor
      Serial.println("Motion ended!");
      // Update pirState to indicate no motion
      pirState = LOW;
    }
    // Delay for 1 second
    delay(1000);
  }
    int rawValue = analogRead(NTC_PIN);
  float voltage = (rawValue / 4095.0) * 3.3; // Assuming ESP32 ADC has a 12-bit resolution (4096 levels) and operates at 3.3V

  // Calculate resistance of NTC thermistor using voltage divider formula
  float resistance = (3.3 * 10000) / voltage - 10000;

  // Assuming a 10KΩ NTC thermistor, use Steinhart-Hart equation to calculate temperature
  float A = 0.003354016;  // Steinhart-Hart coefficients
  float B = 0.000256985;
  float C = 0.000002620131;
  float tempK = 1 / (A + B * log(resistance) + C * pow(log(resistance), 3));
  float tempC = tempK - 273.15;

  Serial.print("Temperature: ");
  Serial.print(tempC);
  Serial.println("C");

  if (tempC > TEMPERATURE_THRESHOLD) {
    // Alarm condition
    // You can add code here to trigger an external alarm or take other actions
  }

  delay(1000); // Wait for 1 second before updating temperature

  // reads the input on analog pin (value between 0 and 4095)
  int analogValue = analogRead(LIGHT_SENSOR_PIN);

  Serial.print("Analog Value = ");
  Serial.print(analogValue);   // the raw analog reading

  // We'll have a few threshholds, qualitatively determined
  if (analogValue < 40) {
    Serial.println(" => Dark");
  } else if (analogValue < 800) {
    Serial.println(" => Dim");
  } else if (analogValue < 2000) {
    Serial.println(" => Light");
  } else if (analogValue < 3200) {
    Serial.println(" => Bright");
  } else {
    Serial.println(" => Very bright");
  }

  delay(500);
}