#include <avr/wdt.h> // Include watchdog timer library
#include "HX711.h"  // Include HX711 library

// Pin Definitions
const int analogPin = 3;       // Potentiometer pin for delay adjustment
const int dtPin = 2;           // HX711 Data pin
const int sckPin = 1;          // HX711 Clock pin
const int fetPin = 0;          // PWM pin for FET control
const int relayPin = 1;        // Relay pin

// HX711 Object
HX711 scale;

void setup() {
    pinMode(fetPin, OUTPUT);
    pinMode(relayPin, OUTPUT);

    digitalWrite(fetPin, HIGH);     // Set FET to High State (initial state)
    digitalWrite(relayPin, LOW);    // Set relay to normally closed (initial state)

    // Initialize Watchdog Timer
    wdt_enable(WDTO_250MS);         // Set watchdog timer to 250 milliseconds

    // Initialize HX711
    scale.begin(dtPin, sckPin);
    scale.set_scale();              // Set scale to default (calibrate later if necessary)
    scale.tare();                  // Reset the scale to 0
    
    // Initialize analog reference and ADC
    analogReference(DEFAULT);       // Set ADC reference to default (Vcc)
    analogRead(analogPin);          // Perform a dummy read to initialize the ADC
}

void loop() {
    static unsigned long lastDebounceTime = 0;
    const unsigned long debounceDelay = 50; // Debounce time in milliseconds

    // Read HX711 value
    long strainGaugeValue = scale.get_units(); // Read force value from HX711

    // Read potentiometer value and map it to delay time
    int potValue = analogRead(analogPin);
    unsigned long delayTime = map(potValue, 0, 1023, 40, 500); // Map potentiometer value to delay range (40 to 500 ms)

    // Check if strain gauge value exceeds the force threshold
    if (strainGaugeValue > 512) { // Adjust threshold based on calibration
        if ((millis() - lastDebounceTime) > debounceDelay) {
            delayMicroseconds(10); // Small delay for sensor stabilization
            
            // Confirm the sensor value is still above the threshold
            if (scale.get_units() > 512) { // Confirm force is still above threshold
                digitalWrite(relayPin, HIGH);   // Activate relay to allow FET operation
                digitalWrite(fetPin, LOW);      // Cut FET

                delay(delayTime);              // Wait according to potentiometer value

                // Ramp up FET signal
                for (int loop = 40; loop <= 255; loop++) {
                    analogWrite(fetPin, loop);   // Start sending signal to FET
                    digitalWrite(relayPin, HIGH);  // Keep relay activated
                    delayMicroseconds(320);      // Loop delay
                }

                digitalWrite(fetPin, HIGH);     // After loop, set FET to full power
                digitalWrite(relayPin, LOW);   // Turn off relay to allow direct power

                // Wait for the sensor to be released with a more efficient debounce
                unsigned long sensorReleaseStart = millis();
                while (scale.get_units() > 512) { // Confirm force is below threshold
                    if (millis() - sensorReleaseStart > debounceDelay * 4) { // Timeout after 4x debounceDelay
                        break;
                    }
                }

                lastDebounceTime = millis();  // Update debounce time
            }
        }
    }

    wdt_reset();  // Reset watchdog timer
}