Proposed Arduino Code for Button-Controlled Stepper Motor

#include <Stepper.h>

// STEPPER SETUP 
const int stepsPerRevolution = 2048;
const int rpm = 5;

//Pins: IN1, IN3, IN2, IN4
Stepper myStepper(stepsPerRevolution, 8, 10, 9, 11);

// Button + Interrupt Set Up
const int buttonPin = 2;  // external interrupt pin INT0

volatile bool buttonPressed = false;  // set in ISR
bool motorOn = false;                 // main motor state

// Interrupt Service Routine: just flag that the button was pressed
void buttonISR() {
  buttonPressed = true;
}

void setup() {
  myStepper.setSpeed(rpm);

  // Button with internal pull-up
  pinMode(buttonPin, INPUT_PULLUP);

  // Trigger on FALLING edge (HIGH -> LOW when button pressed)
  attachInterrupt(digitalPinToInterrupt(buttonPin), buttonISR, FALLING);
}

void loop() {
  // Handle button press in main code (not inside ISR)
  if (buttonPressed) {
    buttonPressed = false;  // clear flag

    // Simple debounce
    static unsigned long lastToggleTime = 0;
    unsigned long now = millis();
    if (now - lastToggleTime > 200) {   // 200 ms debounce
      motorOn = !motorOn;               // toggle motor state
      lastToggleTime = now;
    }
  }

  // If motorOn, keep stepping
  if (motorOn) {
    myStepper.step(1);   // small steps so we can react quickly to button
  }
}