#include <LiquidCrystal.h>

// Pin Assignments
#define LDR_PIN   PA0  // LDR sensor analog pin
#define NTC_PIN   PA1  // NTC sensor analog pin
#define LED_PIN   PA5  // LED control pin
#define FAN_THRESHOLD 25  // Temperature threshold in °C
#define LDR_THRESHOLD 500 // Light threshold for LED ON

// LCD Pin Configuration: RS, EN, D4, D5, D6, D7
LiquidCrystal lcd(PB0, PB1, PB2, PB3, PB4, PB5);

void setup() {
    pinMode(LED_PIN, OUTPUT);
    lcd.begin(16, 2);
    lcd.print("System Ready");
    delay(1000);
    lcd.clear();
}

void loop() {
    int ldrValue = analogRead(LDR_PIN);
    int ntcValue = analogRead(NTC_PIN);
    
    // Convert NTC analog value to temperature (approximate formula)
    float voltage = ntcValue * (3.3 / 4095.0);  // STM32 ADC 12-bit (0-4095)
    float resistance = (10000 * voltage) / (3.3 - voltage);
    float temperature = 1 / ((log(resistance / 10000) / 3950) + (1.0 / 298.15)) - 330.1; 

    // LED control based on LDR threshold
    if (ldrValue > LDR_THRESHOLD) {
        digitalWrite(LED_PIN, HIGH);
    } else {
        digitalWrite(LED_PIN, LOW);
    }

    // LCD display for FAN ON/OFF based on temperature threshold
    lcd.setCursor(0, 0);
    lcd.print("Temp: ");
    lcd.print(temperature, 1);
    lcd.print(" C  ");

    lcd.setCursor(0, 1);
    if (temperature >= FAN_THRESHOLD) {
        lcd.print("FAN: ON ");
    } else {
        lcd.print("FAN: OFF");
    }

    delay(1000); // Update every second
}