#include <Arduino.h>
#include <math.h>  // For log function
#include <Servo.h> // For controlling the servo fan
#include <LiquidCrystal.h> // For 16x2 LCD
 
// ----- CONFIGURATION -----
const int NTC_PIN = PA1;           // Analog pin connected to NTC voltage divider
const int LED_PIN = PA5;           // Digital pin for alarm LED
const int FAN_SERVO_PIN = PB1;     // PWM pin controlling the servo fan
const int BUZZER_PIN = PA6;        // Digital pin for buzzer
 
// LCD pins: RS, EN, D4, D5, D6, D7
LiquidCrystal lcd(PA0, PA3, PB4, PB5, PB6, PB7);
 
const float VCC = 3.3;            
const float R_FIXED = 10000;      
const float R0 = 10000;            
const float BETA = 3950;          
const float T0 = 298.15;          
const float TEMP_BLINK_START = 50;
const float TEMP_MAX = 80;        
const int BLINK_MAX = 150;        
const int BLINK_MIN = 500;        
const int SERVO_MIN_ANGLE = 0;    
const int SERVO_MAX_ANGLE = 180;  
const float BUZZER_START_TEMP = 60;
const float BUZZER_MAX_TEMP = TEMP_MAX;
 
// ----- GLOBALS -----
Servo fanServo;                    
int servoAngle = SERVO_MIN_ANGLE;  
bool direction = true;
 
// ----- SETUP -----
void setup() {
  Serial.begin(115200);
  analogReadResolution(12); // STM32 ADC is 12-bit (0-4095)
 
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);
 
  pinMode(BUZZER_PIN, OUTPUT);
  digitalWrite(BUZZER_PIN, LOW);
 
  fanServo.attach(FAN_SERVO_PIN);
  fanServo.write(servoAngle);
 
  lcd.begin(16, 2);
  lcd.print("Temp Monitor");
}
 
// ----- LOOP -----
void loop() {
  // ----- Read temperature -----
  int adcValue = analogRead(NTC_PIN);
  float Vout = (adcValue / 4095.0) * VCC;
  float Rntc = (R_FIXED * Vout) / (VCC - Vout);
  float tempK = 1 / ((1 / T0) + (1 / BETA) * log(Rntc / R0));
  float tempC = tempK - 273.15;
 
  Serial.print("Temperature: ");
  Serial.print(tempC, 2);
  Serial.println(" °C");
 
  // ----- LCD DISPLAY -----
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(tempC, 1);
  lcd.print((char)223); // degree symbol
  lcd.print("C");
 
  lcd.setCursor(0, 1);
  if (tempC < 50) {
    lcd.print("Status: Normal   ");
  } else if (tempC < 70) {
    lcd.print("Warning: Heating");
  } else {
    lcd.print("OVERLOAD! Critical");
  }
 
  // ----- LED ALERT LOGIC -----
  if (tempC < TEMP_BLINK_START) {
    digitalWrite(LED_PIN, LOW);
    delay(1000);
  } else {
    float tempForBlink = tempC;
    if (tempForBlink > TEMP_MAX) tempForBlink = TEMP_MAX;
    int blinkDelay = map(tempForBlink * 10, TEMP_BLINK_START * 10, TEMP_MAX * 10, BLINK_MIN, BLINK_MAX);
    digitalWrite(LED_PIN, HIGH);
    delay(blinkDelay / 2);
    digitalWrite(LED_PIN, LOW);
    delay(blinkDelay / 2);
  }
 
  // ----- BUZZER LOGIC -----
  if (tempC >= BUZZER_START_TEMP) {
    int buzzerDelay = map(tempC * 10, BUZZER_START_TEMP * 10, BUZZER_MAX_TEMP * 10, 200, 50);
    digitalWrite(BUZZER_PIN, HIGH);
    delay(buzzerDelay / 2);
    digitalWrite(BUZZER_PIN, LOW);
    delay(buzzerDelay / 2);
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }
 
  // ----- SERVO FAN SIMULATION -----
  float tempForFan = tempC;
  if (tempForFan < TEMP_BLINK_START) tempForFan = TEMP_BLINK_START;
  if (tempForFan > TEMP_MAX) tempForFan = TEMP_MAX;
 
  int stepSize = map(tempForFan * 10, TEMP_BLINK_START * 10, TEMP_MAX * 10, 5, 20);
  int servoDelay = map(tempForFan * 10, TEMP_BLINK_START * 10, TEMP_MAX * 10, 5, 0);
 
  if (direction) {
    servoAngle += stepSize;
    if (servoAngle >= SERVO_MAX_ANGLE) direction = false;
  } else {
    servoAngle -= stepSize;
    if (servoAngle <= SERVO_MIN_ANGLE) direction = true;
  }
  fanServo.write(servoAngle);
  delay(servoDelay);
}