mega_stepper_button_01

/*
   15 February 2018
   This is a test sketch to operate a reversible stepper motor on an Arduino Mega.
   The stepper motor spins all the time, but pressing the button reverses the motor for 1 rotation cycle.

   This sketch uses a 'normal' software button debounce,
   where the debounce time is tracked separately and resets itself no matter what else is happening.
*/

#include <Stepper.h>

const int stepsPerRevolution = 128;
const int inPin = 52;
int val = 0;
Stepper myStepper(stepsPerRevolution, 3, 5, 4, 6);
int stepperDirection = 0; // This is used to hold a modified value of stepsPerRevolution (either positive or negative) without changing the original value.

// Below is variables for debouncing the button input.
bool button_enabled = true;
int button_debounce_time = 500; // This is the time in milliseconds for the button to de-bounce (half a second).
unsigned long buttonPress_beginTime = 0;
unsigned long buttonPress_currentTime = 0;

void setup() {
  myStepper.setSpeed(120);
  pinMode(inPin, INPUT);
  // This sketch uses pin 13 to indicate if the button input is enabled or not.
  pinMode(13, OUTPUT);
  digitalWrite(13, HIGH);
}

void loop() {

  if (button_enabled == true) {
    val = digitalRead(inPin);
    if (val == 1) {
      button_enabled = false;
      digitalWrite(13, LOW);
      buttonPress_beginTime = millis();
    }
  }
  else {
    // This part is what happens after a button has been pressed.
    // This is how you would usually use a software button debounce,
    // since most events will take less time to complete than the button debounce time.
    buttonPress_currentTime = millis();
    if (buttonPress_currentTime >= buttonPress_beginTime) {
      if (buttonPress_currentTime >= (buttonPress_beginTime + button_debounce_time)) {
        // If (button_debounce_time) has passed since (buttonPress_beginTime), then-
        button_enabled = true; // re-enable the button
        val = 0; // set the direction back to zero
        digitalWrite(13, HIGH); // turn pin 13 back on
      }
    }
    else {
      buttonPress_beginTime = millis(); // millis() rollover condition.
    }
  }

  if (val == HIGH) {
    stepperDirection = stepsPerRevolution;
  }
  else {
    stepperDirection = (stepsPerRevolution * -1);
  }
  myStepper.step(stepperDirection);
}