#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <math.h> // 引入數學函式庫
#include <TimerOne.h>

#define BETA 3950 // Beta 系數
#define THERMISTOR_PIN A0 // NTC 感測器連接的腳位
#define RED_LED_PIN 5 // 紅燈
#define YELLOW_LED_PIN 6 // 黃燈
#define GREEN_LED_PIN 7 // 綠燈

#define Button 2

LiquidCrystal_I2C lcd(0x27, 16, 2);

//宣告變數在外面

float celsius = 0.0;
int analogValue;

float maxTemp = -30.0;
float minTemp = 90.0;

volatile bool displayMode = 0; // 顯示模式 (0：即時溫度，1：最大/最小溫度)


void setup() {



  lcd.init();
  lcd.backlight();//初始化

  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(YELLOW_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  lcd.setCursor(0, 0);
  lcd.print("Temp Monitor");

  Timer1.initialize(1000000); // 初始化 Timer1，設置週期為 1 秒 (1000000 微秒)
  Timer1.attachInterrupt(timerISR);

  pinMode(Button, INPUT_PULLUP);
  attachInterrupt( digitalPinToInterrupt(2), my_ISR, FALLING);
}

void loop() {


  

if (displayMode == 0) {
  // 顯示溫度於 LCD
  lcd.setCursor(0, 0);
  lcd.print("Current Temp:  ");//空白覆蓋
  lcd.setCursor(0, 1);
  lcd.print(celsius);
  lcd.print(" C         ");//空白覆蓋
   } else {
    // 模式 2：顯示最大和最小溫度
    lcd.setCursor(0, 0);
    lcd.print("MaxTemp:");
    lcd.print(maxTemp, 1);
    lcd.print(" C");

    lcd.setCursor(0, 1);
    lcd.print("MinTemp:");
    lcd.print(minTemp, 1);
    lcd.print(" C");

   
  }

  // 判斷溫度範圍並控制 LED
  if (celsius < 20) {
    digitalWrite(GREEN_LED_PIN, HIGH);
    digitalWrite(YELLOW_LED_PIN, LOW);
    digitalWrite(RED_LED_PIN, LOW);
  } else if (celsius >= 20 && celsius < 30) {
    digitalWrite(GREEN_LED_PIN, LOW);
    digitalWrite(YELLOW_LED_PIN, HIGH);
    digitalWrite(RED_LED_PIN, LOW);
  } else {
    digitalWrite(GREEN_LED_PIN, LOW);
    digitalWrite(YELLOW_LED_PIN, LOW);
    digitalWrite(RED_LED_PIN, HIGH);
  }

}


void timerISR() {
  {
    analogValue = analogRead(THERMISTOR_PIN); // 讀取 ADC 值
    celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;

    if (celsius > maxTemp) {
      maxTemp = celsius;
    }
    if (celsius < minTemp) {
      minTemp = celsius;
    }
  }
}


void my_ISR() {
 
 static unsigned long lastInterruptTime = 0;
  unsigned long interruptTime = millis();

  // 防止按鈕抖動，設定防抖延遲 200ms
  if (interruptTime - lastInterruptTime > 200) {
    displayMode = !displayMode; // 切換顯示模式
  }

  lastInterruptTime = interruptTime;


}