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

// Pin definitions
#define DATA_PIN  15
#define CLOCK_PIN 2
#define BUZZER_PIN 13

// WiFi and ThingSpeak credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const unsigned long CHANNEL_ID = 2040615;
const char* WRITE_API_KEY = "BJGXAH2S16ZAWZ13";

// HX711 load cell setup
HX711 hx711;

// Variables
long weight;
int buzzerState = 0;
WiFiClient client;

void setup() {
  Serial.begin(115200);
  
  // Initialize HX711
  hx711.begin(DATA_PIN, CLOCK_PIN);
  hx711.set_scale(420.0983); // Adjust this to your load cell calibration factor
  hx711.tare(); // Reset the scale to 0

  // Initialize Buzzer Pin
  pinMode(BUZZER_PIN, OUTPUT);
  noTone(BUZZER_PIN); // Ensure buzzer is off

  // Connect to WiFi
  connectToWiFi();

  // Initialize ThingSpeak
  ThingSpeak.begin(client);
}

void loop() {
  // Read weight from HX711
  weight = hx711.get_units();
  
  // Map the weight to a range (0 to 3500 in this example)
  int mappedWeight = map(weight, 0, 50, 0, 3500);

  // Handle buzzer based on weight
  if (mappedWeight > 2500) {
    buzzerState = 1; // Overload condition
    tone(BUZZER_PIN, 1000); // Play buzzer sound
  } else if (mappedWeight < 500) {
    buzzerState = 0; // Normal condition
    noTone(BUZZER_PIN); // Turn off buzzer
  } else {
    buzzerState = 2; // Intermediate condition
    noTone(BUZZER_PIN); // Turn off buzzer
  }

  // Send data to ThingSpeak
  ThingSpeak.setField(1, weight);
  ThingSpeak.setField(2, buzzerState); // 0: Off, 1: On, 2: Normal

  // Write the fields to ThingSpeak
  int statusCode = ThingSpeak.writeFields(CHANNEL_ID, WRITE_API_KEY);
  if (statusCode == 200) {
    Serial.println("Channel update successful.");
  } else {
    Serial.println("Problem Writing data. HTTP error code: " + String(statusCode));
  }

  // Wait 15 seconds before the next update
  delay(15000);
}

// Function to connect to WiFi
void connectToWiFi() {
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("Connected to WiFi.");
}