#include "HX711.h"
#include <Wire.h>
#include "RTClib.h"
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// OLED setup
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// RTC
RTC_DS1307 rtc;

// HX711
HX711 scale1, scale2, scale3, scale4;

// Pins
#define DT1 4
#define SCK1 5

#define DT2 18
#define SCK2 19

#define DT3 32
#define SCK3 33

#define DT4 25
#define SCK4 26

#define BUZZER 27

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

  // HX711
  scale1.begin(DT1, SCK1);
  scale2.begin(DT2, SCK2);
  scale3.begin(DT3, SCK3);
  scale4.begin(DT4, SCK4);

  // RTC
  Wire.begin(21, 22);
  if (!rtc.begin()) {
    Serial.println("RTC not found!");
  }

  // OLED
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED not found!");
    while (true);
  }

  display.clearDisplay();

  pinMode(BUZZER, OUTPUT);

  Serial.println("System Test Start...");
}

void loop() {

  // Read time
  DateTime now = rtc.now();

  // Read sensors
  long w1 = scale1.is_ready() ? scale1.read() : 0;
  long w2 = scale2.is_ready() ? scale2.read() : 0;
  long w3 = scale3.is_ready() ? scale3.read() : 0;
  long w4 = scale4.is_ready() ? scale4.read() : 0;

  // Serial output
  Serial.print("Time: ");
  Serial.print(now.hour()); Serial.print(":");
  Serial.print(now.minute()); Serial.print(":");
  Serial.println(now.second());

  Serial.print("T1: "); Serial.print(w1);
  Serial.print(" | T2: "); Serial.print(w2);
  Serial.print(" | T3: "); Serial.print(w3);
  Serial.print(" | T4: "); Serial.println(w4);

  Serial.println("----------------------");

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

  display.print("Time: ");
  display.print(now.hour());
  display.print(":");
  display.println(now.minute());

  display.print("T1: "); display.println(w1);
  display.print("T2: "); display.println(w2);
  display.print("T3: "); display.println(w3);
  display.print("T4: "); display.println(w4);

  display.display();

  // Buzzer test (beep every 5 sec)
  digitalWrite(BUZZER, HIGH);
  delay(200);
  digitalWrite(BUZZER, LOW);

  delay(3000);
}