#include <math.h>

// Define Pins
const int potPin = 34;   // Potentiometer
const int ldrPin = 35;   // LDR Sensor
const int ntcPin = 32;   // NTC Thermistor
const int ledPin = 5;    // LED PWM output

// Constants for ADC
const int adcMax = 4095; // ESP32 ADC 12-bit max value
const float vRef = 3.3;  // Reference voltage

// Constants for NTC Thermistor
const float BETA = 3950; // Beta coefficient of the thermistor
const float R0 = 10000;  // 10kΩ resistor at 25°C
const float T_zero = 298.15; // Reference temperature in Kelvin (25°C)

// Constants for LDR
const float ldrResistor = 10000; // 10kΩ pull-down resistor

void setup() {
    Serial.begin(115200);
    pinMode(ledPin, OUTPUT);
}

void loop() {
    // Read ADC values
    int potValue = analogRead(potPin);
    int ldrValue = analogRead(ldrPin);
    int ntcValue = analogRead(ntcPin);

    // Convert Potentiometer ADC value to PWM (0-255)
    int potBrightness = map(potValue, 0, adcMax, 0, 255);
    analogWrite(ledPin, potBrightness);

    // Convert LDR ADC to Resistance
    float vLDR = (ldrValue / (float)adcMax) * vRef;
    float rLDR = (vRef * ldrResistor / vLDR) - ldrResistor;

    // Convert LDR Resistance to Lux (approximation formula)
    float lux = pow(10, (log10(rLDR) - 1.5)); // Approximate Lux conversion

    // Adjust LED brightness using LDR (higher light = dimmer LED)
    int ldrBrightness = map(lux, 0, 1000, 255, 0); // 0 lux = max brightness
    analogWrite(ledPin, ldrBrightness);

    // Convert ADC value to Voltage for NTC
    float vNTC = (ntcValue / (float)adcMax) * vRef;

    // Convert Voltage to Resistance for NTC
    float rNTC = (vRef * R0 / vNTC) - R0;

    // Calculate Temperature using the Steinhart-Hart Equation
    float temperature = 1 / ((log(rNTC / R0) / BETA) + (1 / T_zero)) - 273.15;

    // Print values to Serial Monitor
    Serial.print("Potentiometer: "); Serial.print(potValue);
    Serial.print(" | LDR: "); Serial.print(ldrValue);
    Serial.print(" | LDR Lux: "); Serial.print(lux);
    Serial.print(" | NTC Temp: "); Serial.print(temperature); Serial.println(" °C");

    delay(500);
}