#include <WiFi.h>
#include <HTTPClient.h>
#include <HX711.h>

// HX711 circuit wiring
#define LOADCELL_DOUT_PIN 21
#define LOADCELL_SCK_PIN 22

// Alarm settings
#define ALARM_PIN 23
#define OVERLOAD_THRESHOLD 2500 // kg

HX711 scale;

// Wi-Fi settings
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ThingSpeak settings
const char* server = "api.thingspeak.com";
const char* apiKey = "BTB198A7IWZRC8AS";

void setup() {
  Serial.begin(115200);
  scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
  scale.set_scale(); // Set the scale factor here (calibrate as needed)
  scale.tare(); // Reset the scale to 0

  pinMode(ALARM_PIN, OUTPUT);
  digitalWrite(ALARM_PIN, LOW); // Turn off the alarm initially

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi");
}

void loop() {
  float weight = scale.get_units(10); // Average over 10 readings

  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    String url = String("http://") + server + "/update?api_key=" + apiKey + "&field1=" + String(weight);
    
    http.begin(url);
    int httpCode = http.GET();
    if (httpCode > 0) {
      Serial.println("Data sent to ThingSpeak");
    } else {
      Serial.println("Error sending data");
    }
    http.end();
  }

  // Check if weight exceeds the threshold
  if (weight > OVERLOAD_THRESHOLD) {
    Serial.println("Overload! Activating alarm...");
    digitalWrite(ALARM_PIN, HIGH); // Activate alarm
  } else {
    digitalWrite(ALARM_PIN, LOW); // Deactivate alarm
  }

  delay(10000); // Update every 20 seconds
}