#include <Adafruit_GFX.h>
#include <Adafruit_ILI9341.h>
#include <SPI.h>
#include <DHT.h>

#define TFT_CS     5
#define TFT_RST    16
#define TFT_DC     17
#define DHT_PIN    12     // Pin connected to DHT22 sensor
#define RELAY_PIN  14    // Pin connected to relay

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

#define DHTTYPE    DHT22   // DHT 22  (AM2302), AM2321
DHT dht(DHT_PIN, DHTTYPE);

void setup() {
  Serial.begin(115200);

  pinMode(RELAY_PIN, OUTPUT);

  // Initialize TFT display
  tft.begin();
  tft.setRotation(4); // Rotate screen 90 degrees

  // Set background color
  tft.fillScreen(ILI9341_BLACK); // Set background color to white

  // Set text size
  tft.setTextSize(2);

  // Draw title
  tft.setTextColor(ILI9341_WHITE);
  tft.setCursor(10, 10);
  tft.println("Temperature Control");

  // Draw top border
  tft.drawRect(0, 0, tft.width(), 20, ILI9341_WHITE);
  
  // Initialize DHT sensor
  dht.begin();
}

void loop() {
  // Read temperature from DHT sensor
  float temperature = dht.readTemperature();

  // Check if temperature is valid
  if (!isnan(temperature)) {
    // Print temperature to serial monitor
    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.println(" °C");

    // Turn on relay if temperature is lower than 20°C
    if (temperature < 20) {
      digitalWrite(RELAY_PIN, HIGH);
      Serial.println("Relay: ON");
      drawRelayStatus(true); // Draw relay status on TFT display (ON)
    } else {
      digitalWrite(RELAY_PIN, LOW);
      Serial.println("Relay: OFF");
      drawRelayStatus(false); // Draw relay status on TFT display (OFF)
    }

    // Draw temperature on TFT display
    drawTemperature(temperature);
  } else {
    Serial.println("Failed to read temperature from DHT sensor");
  }

  delay(2000); // Wait 2 seconds before next reading
}

void drawTemperature(float temp) {
  // Clear previous temperature
  tft.fillRect(0, 30, 240, 30, ILI9341_BLACK); // Clear temperature area

  // Draw current temperature
  tft.setTextColor(ILI9341_WHITE);
  tft.setCursor(10, 40);
  tft.setTextSize(2);
  tft.print("Temp: ");
  tft.print(temp);
  tft.println("C");
}

void drawRelayStatus(bool isOn) {
  // Clear previous relay status
  tft.fillRect(0, 80, 240, 30, ILI9341_BLACK); // Clear relay status area

  // Set text color
  tft.setTextColor(isOn ? ILI9341_GREEN : ILI9341_RED); // Green if ON, red if OFF

  // Draw current relay status
  tft.setCursor(30, 90);
  tft.setTextSize(3);

  tft.print("Relay: ");
  tft.println(isOn ? "ON" : "OFF");
  

}