#include <Arduino.h>
#include "HX711.h"

// HX711 circuit wiring
const int LOADCELL_DOUT_PIN = 12; // DOUT pin on HX711
const int LOADCELL_SCK_PIN = 13; // SCK pin on HX711
HX711 scale; // Declare the HX711 object globally

// Relay module control pin
const int relayPin = 14; // GPIO pin connected to the relay module

// Calibration factor (fixed for 5 kg weight based on raw value of 2100)
float raw_value_per_kg = 420.0; // Calibration factor for 5 kg (2100 raw value)

// Flag to indicate calibration status
bool isCalibrated = true;

void setup() {
    Serial.begin(115200);
    Serial.println("ESP8266 Weight Detection and Relay Control");

    // Initialize HX711
    scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
    scale.tare(); // Reset scale to 0
    Serial.println("Scale initialized. Calibration factor set for 5 kg.");

    // Initialize the relay module pin
    pinMode(relayPin, OUTPUT);
    digitalWrite(relayPin, LOW); // Ensure relay is OFF initially
}

void loop() {
    if (scale.is_ready() && isCalibrated) {
        // Get raw ADC value
        long raw_value = scale.get_units(10); // Average of 10 readings

        // Convert raw ADC value to kilograms
        float weight_kg = raw_value / raw_value_per_kg;

        // Display weight
        Serial.print("Raw Value: ");
        Serial.print(raw_value);
        Serial.print(", Weight: ");
        Serial.print(weight_kg, 2); // 2 decimal places
        Serial.println(" kg");

        // Control the relay based on weight
        if (weight_kg > 0) {
            digitalWrite(relayPin, HIGH); // Activate relay (lock engaged)
            Serial.println("Relay ON (Locking)");
        } else {
            digitalWrite(relayPin, LOW); // Deactivate relay (lock disengaged)
            Serial.println("Relay OFF (Unlocking)");
        }
    } else if (!scale.is_ready()) {
        Serial.println("HX711 not detected. Check wiring.");
    }

    delay(2000); // Delay for 2 seconds
}