#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHT.h>
#include <HX711.h>

// OLED 
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// DHT22 
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// HX711 
#define HX711_DOUT 2
#define HX711_SCK 14
HX711 scale;

// LDR 
// Documentation: https://docs.wokwi.com/parts/wokwi-photoresistor-sensor#pin-names$0
#define LDR_ANALOG 18
#define LDR_DIGITAL 19

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

  dht.begin();
  scale.begin(HX711_DOUT, HX711_SCK);

  pinMode(LDR_DIGITAL, INPUT);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("ERROR"));
    for (;;);
  }

  display.clearDisplay();
  display.setTextColor(WHITE);
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.println("System Ready");
  display.display();
  delay(1000);
}

void loop() {
  // Read sensors
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  long weight = 0;
  if (scale.is_ready()) {
    weight = scale.get_units(5);
  }

  int ldrValue = analogRead(LDR_ANALOG);   
  int ldrDigital = digitalRead(LDR_DIGITAL);

  // Serial Output
  Serial.print("Temp : "); Serial.print(temp); Serial.print(" C | ");
  Serial.print("Hum : "); Serial.print(hum); Serial.print(" % | ");
  Serial.print("Weight : "); Serial.print(weight); Serial.print(" g | ");
  Serial.print("Light : "); Serial.println(ldrValue);

  // OLED Output
  display.clearDisplay();
  display.setCursor(0, 0);
  display.setTextSize(1);

  display.println("ENVIRONMENT:");
  display.printf("Temp : %.1f C\n", temp);
  display.printf("Hum :  %.1f %%\n", hum);

  display.println("\nLIGHT:");
  display.printf("LDR : %d\n", ldrValue);

  display.println("\nWEIGHT :");
  display.setTextSize(2);
  display.printf("%ld g", weight);

  display.display();
  delay(2000);
}