/*
   Forum: https://forum.arduino.cc/t/turning-a-stepper-motor-off-and-on/1168572
   Wokwi: https://wokwi.com/projects/375870418732018689

*/

// Define pins
constexpr byte reverseSwitch = 2;  // Push button for reverse
constexpr byte  driverPUL = 7;    // PUL- pin
constexpr byte  driverDIR = 6;    // DIR- pin
constexpr byte  spd = A0;     // Potentiometer

// Variables

unsigned long pd = 500;       // Pulse Delay period in microseconds
byte setdir = LOW;            // Set Direction



void setup() {
  pinMode(reverseSwitch, INPUT_PULLUP);
  pinMode (driverPUL, OUTPUT);
  pinMode (driverDIR, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(reverseSwitch),revmotor, FALLING);
}


void loop() {
  pd = map((analogRead(spd)), 0, 1023, 2000, 50);
  if (pd < 1950) {
    digitalWrite(driverDIR, setdir);
    digitalWrite(driverPUL, HIGH);
    delayMicroseconds(pd);
    digitalWrite(driverPUL, LOW);
    delayMicroseconds(pd);
  }
}



void revmotor() {
  static unsigned long lastAction;
  static boolean ISRActive = false;
  if (!ISRActive && millis() - lastAction > 500) {
    ISRActive = true;
  }
  if (ISRActive) {
     ISRActive = false;
     setdir = !setdir;
     lastAction = millis();
  }
}