#include <Servo.h>

const int coolingFanPin = 8;  // Pin connected to the cooling fan
const int loadCellPin = A0;    // Analog pin connected to the load cell
const int servoPin = 9;        // Pin connected to the servo motor
const int stepperPin1 = 4;     // Pin for controlling stepper motor step signal
const int stepperPin2 = 5;     // Pin for controlling stepper motor direction signal
const int dcMotorPin = 6;      // Pin connected to the DC motor

const int fanDuration = 180000; // Duration for running the cooling fan (3 minutes in milliseconds)
const int waitWeight = 100;     // Weight threshold for closing the hatch (in grams)
const int stepperSteps1 = 200;  // Number of steps for the first stepper motor movement
const int stepperSteps2 = 400;  // Number of steps for the second stepper motor movement
const int dcMotorDuration = 3000; // Duration for running the DC motor (3 seconds in milliseconds)

Servo hatchServo;               // Create a servo object for the hatch

void setup() {
  Serial.begin(9600);           // Set serial communication baud rate
  pinMode(coolingFanPin, OUTPUT);
  pinMode(loadCellPin, INPUT);
  hatchServo.attach(servoPin);   // Attach the servo motor to the specified pin
  pinMode(stepperPin1, OUTPUT);
  pinMode(stepperPin2, OUTPUT);
  pinMode(dcMotorPin, OUTPUT);
}

void loop() {
  if (Serial.available() > 0) {  // Check for incoming serial message
    char incomingByte = Serial.read();
    if (incomingByte == 'S') {   // Start command received from Arduino Mega
      Serial.println("Starting process...");

      // Step 1: Run the cooling fan
      digitalWrite(coolingFanPin, HIGH);
      Serial.println("Running cooling fan...");
      delay(fanDuration);
      digitalWrite(coolingFanPin, LOW);

      // Step 2: Open the hatch (180 degrees)
      hatchServo.write(180);
      Serial.println("Opening hatch...");
      delay(2000); // Add a short delay for servo movement

      // Step 3: Wait for weight and close hatch
      int weight = getWeight();  // Read weight from load cell
      while (weight < waitWeight) {
        weight = getWeight();
        delay(1000); // Check weight every second
      }
      hatchServo.write(0);       // Close the hatch
      Serial.println("Hatch closed (weight reached).");

      // Step 4: Run the stepper motor (200 steps)
      runStepperMotor(stepperSteps1);

      // Step 5: Run the DC motor for 3 seconds
      digitalWrite(dcMotorPin, HIGH);
      Serial.println("Running DC motor...");
      delay(dcMotorDuration);
      digitalWrite(dcMotorPin, LOW);

      // Step 6: Run the stepper motor (400 steps)
      runStepperMotor(stepperSteps2);

      Serial.println("Process completed.");
    } else {
      Serial.println("Invalid command received.");
    }
  }
}

int getWeight() {
  int weightRaw = analogRead(loadCellPin);
  // Implement your specific calibration logic here to convert raw ADC value to weight
  // This example assumes a linear conversion (replace with your calibration function)
  return weightRaw / 10; // Replace with your calibration function
}

void runStepperMotor(int steps) {
  for (int i = 0; i < steps; i++) {
    // Implement your specific stepper motor control logic here
    // This example assumes a simple stepping sequence (replace with your driver's logic)
    digitalWrite(stepperPin1, HIGH);
    delayMicroseconds(1000);
    digitalWrite(stepperPin1, LOW);
    delayMicroseconds(1000);
    digitalWrite(stepperPin2, !digitalRead(stepperPin2)); // Toggle direction
  }
}