#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

#define DHTPIN 14     // Digital pin connected to the DHT sensor

#define RELAY_PIN 16 // ESP32 pin GIOP16 connected to the IN pin of relay
#define RELAY_PIN 17

// Uncomment the type of sensor in use:
//#define DHTTYPE    DHT11     // DHT 11
#define DHTTYPE    DHT22     // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)

#define TEMP_UPPER_THRESHOLD  30 // upper temperature threshold
#define TEMP_LOWER_THRESHOLD  15 // lower Humidity threshold
#define HUM_UPPER_THRESHOLD 97
#define HUM_LOWER_THRESHOLD 76

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  pinMode(RELAY_PIN 16, OUTPUT);
  pinMode(RELAY_PIN 17, OUTPUT);
  dht.begin();
  

  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  delay(2000);
  display.clearDisplay();
  display.setTextColor(WHITE);
}

void loop() {
  delay(5000);

  //read temperature and humidity
  float t = dht.readTemperature();
  float h = dht.readHumidity();
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
  }
  // clear display
  display.clearDisplay();
  
  // display temperature
  display.setTextSize(1);
  display.setCursor(0,0);
  display.print("Temperature: ");
  display.setTextSize(2);
  display.setCursor(0,10);
  display.print(t);
  display.print(" ");
  display.setTextSize(1);
  display.cp437(true);
  display.write(167);
  display.setTextSize(2);
  display.print("C");
  
  // display humidity
  display.setTextSize(1);
  display.setCursor(0, 35);
  display.print("Humidity: ");
  display.setTextSize(2);
  display.setCursor(0, 45);
  display.print(h);
  display.print(" %"); 
  
  display.display(); 

  if (isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
  } else {
    if (t > TEMP_UPPER_THRESHOLD) {
      Serial.println("Turn the fan on");
      digitalWrite(RELAY_PIN 16, HIGH); // turn on
    } else if (t < TEMP_LOWER_THRESHOLD) {
      Serial.println("Turn the fan off");
      digitalWrite(RELAY_PIN 16, LOW); // turn off
    }
    if (h < HUM_LOWER_THRESHOLD ){
      Serial.println("turn on water");
      digitalWrite(RELAY_PIN 17, HIGH);
    } else if (h > HUM_UPPER_THRESHOLD){
      Serial.println("Turn OFF Water");
      digitalWrite(RELAY_PIN 17, LOW);
    }
  }

  // wait a 2 seconds between readings
  delay(2000);
}