#include <Wire.h>

#define DHTPIN 2

const float TEMP_THRESHOLD_HIGH = 28.0;
const float TEMP_THRESHOLD_LOW = 22.0; 

const int SERVO_CLOSED = 0;
const int SERVO_OPEN = 90;

float temperature = 0;
bool windowOpen = false;

unsigned long lastReadTime = 0;
const unsigned long READ_INTERVAL = 2000;

byte data[5] = {0, 0, 0, 0, 0};
byte bits = 0;
byte cnt = 7;
byte idx = 0;

#define LCD_ADDR 0x27
#define LCD_COLS 16
#define LCD_ROWS 2

#define LCD_CLEAR 0x01
#define LCD_HOME 0x02
#define LCD_ENTRY_MODE 0x06
#define LCD_DISPLAY_ON 0x0C
#define LCD_FUNCTION_SET 0x28
#define LCD_SET_DDRAM_ADDR 0x80


void lcdSendCommand(byte cmd) {
  Wire.beginTransmission(LCD_ADDR);
  Wire.write(0x00);
  Wire.write(cmd & 0xF0);
  Wire.write((cmd << 4) & 0xF0);
  delayMicroseconds(50);
  Wire.endTransmission();
}

void lcdSendData(byte data) {
  Wire.beginTransmission(LCD_ADDR);
  Wire.write(0x40); 
  Wire.write(data & 0xF0);
  Wire.write((data << 4) & 0xF0);
  delayMicroseconds(50);
  Wire.endTransmission();
}

void lcdInit() {
  delay(50);
  Wire.beginTransmission(LCD_ADDR);
  Wire.write(0x30);
  Wire.endTransmission();
  delay(5);
  
  Wire.beginTransmission(LCD_ADDR);
  Wire.write(0x30);
  Wire.endTransmission();
  delayMicroseconds(150);
  
  Wire.beginTransmission(LCD_ADDR);
  Wire.write(0x30);
  Wire.endTransmission();
  
  Wire.beginTransmission(LCD_ADDR);
  Wire.write(0x20);
  Wire.endTransmission();
  
  // Настройка дисплея
  lcdSendCommand(LCD_FUNCTION_SET);
  lcdSendCommand(LCD_DISPLAY_ON);
  lcdSendCommand(LCD_CLEAR);
  lcdSendCommand(LCD_ENTRY_MODE);
  delay(2);
}

void lcdPrint(const char* str) {
  while (*str) {
    lcdSendData(*str++);
  }
}

void lcdSetCursor(byte col, byte row) {
  byte address = col;
  if (row == 1) address += 0x40;
  lcdSendCommand(LCD_SET_DDRAM_ADDR | address);
}


void servoWrite(int angle) {
  int pulse = map(angle, 0, 180, 544, 2400);
  
  digitalWrite(9, HIGH);
  delayMicroseconds(pulse);
  digitalWrite(9, LOW);
  
  delay(20);
}

void dhtBegin() {
  pinMode(DHTPIN, OUTPUT);
  digitalWrite(DHTPIN, HIGH);
  delay(250);
}

byte dhtRead() {
  byte data = 0;
  
  for (int i = 0; i < 8; i++) {
    while (digitalRead(DHTPIN) == LOW);
    
    delayMicroseconds(30); // Ждем 30 мкс
    
    if (digitalRead(DHTPIN) == HIGH) {
      data |= (1 << (7 - i));
    }
    
    while (digitalRead(DHTPIN) == HIGH);
  }
  
  return data;
}

float readTemperature() {
  for (int i = 0; i < 5; i++) data[i] = 0;
  
  pinMode(DHTPIN, OUTPUT);
  digitalWrite(DHTPIN, LOW);
  delay(2);
  digitalWrite(DHTPIN, HIGH);
  delayMicroseconds(40);
  
  pinMode(DHTPIN, INPUT_PULLUP);
  delayMicroseconds(10);
  
  if (digitalRead(DHTPIN) == LOW) {
    delayMicroseconds(80);
    
    if (digitalRead(DHTPIN) == HIGH) {
      delayMicroseconds(80);
      
      for (int i = 0; i < 40; i++) {
        while (digitalRead(DHTPIN) == LOW);
        
        delayMicroseconds(30);
        
        if (digitalRead(DHTPIN) == HIGH) {
          data[i/8] |= (1 << (7 - (i % 8)));
        }
        
        while (digitalRead(DHTPIN) == HIGH);
      }
      
      byte checksum = data[0] + data[1] + data[2] + data[3];
      if (data[4] == checksum) {
        int tempRaw = (data[2] << 8) | data[3];
        
        if (tempRaw & 0x8000) {
          tempRaw = -(tempRaw & 0x7FFF);
        }
        
        return tempRaw / 10.0;
      }
    }
  }
  
  return NAN;
}


void setup() {
  Serial.begin(9600);
  
  Wire.begin();
  lcdInit();
  
  pinMode(9, OUTPUT);
  servoWrite(SERVO_CLOSED);
  
  dhtBegin();
  
  lcdPrint("Thermostat v1.0");
  delay(2000);
  lcdSendCommand(LCD_CLEAR);
  
  lcdPrint("Initializing...");
  delay(1000);
  lcdSendCommand(LCD_CLEAR);
}

void loop() {
  unsigned long currentTime = millis();
  
  if (currentTime - lastReadTime >= READ_INTERVAL) {
    lastReadTime = currentTime;
    
    temperature = readTemperature();
    
    if (isnan(temperature)) {
      Serial.println("Error reading DHT22!");
      lcdSendCommand(LCD_CLEAR);
      lcdPrint("DHT Error!");
      return;
    }
    
    if (temperature > TEMP_THRESHOLD_HIGH && !windowOpen) {
      for (int angle = SERVO_CLOSED; angle <= SERVO_OPEN; angle += 5) {
        servoWrite(angle);
        delay(50);
      }
      windowOpen = true;
      Serial.println("Window: OPEN");
    } 
    else if (temperature < TEMP_THRESHOLD_LOW && windowOpen) {
      for (int angle = SERVO_OPEN; angle >= SERVO_CLOSED; angle -= 5) {
        servoWrite(angle);
        delay(50);
      }
      windowOpen = false;
      Serial.println("Window: CLOSED");
    }
    
    Serial.print("Temperature: ");
    Serial.print(temperature, 1);
    Serial.print("C | Window: ");
    Serial.println(windowOpen ? "Open" : "Closed");
    
    lcdSetCursor(0, 0);
    lcdPrint("Temp: ");
    
    char tempStr[10];
    dtostrf(temperature, 4, 1, tempStr);
    lcdPrint(tempStr);
    lcdPrint("C ");
    
    lcdSetCursor(0, 1);
    lcdPrint("Window: ");
    lcdPrint(windowOpen ? "OPEN " : "CLOSED");
    
    for (int i = 12; i < 16; i++) {
      lcdSetCursor(i, 1);
      lcdPrint(" ");
    }
  }
  
  delay(100);
}