Stepper Unit

// Test: Ramping speed while button pressed (Common-Anode)
// PUL+/DIR+/ENA+ -> +5V
// PUL- -> STEP (D9), DIR- -> DIR (D8), ENA- -> ENA (D7 or GND)
// Buttons: BTN_R (D3) for direction right, BTN_L (D2) for left (INPUT_PULLUP)
// LEDs: RED (D4, leuchtet wenn Motor läuft), GREEN (D5, leuchtet wenn Motor stillsteht)

#define STEP 9
#define DIR  8
#define ENA  7
#define BTN_L 2
#define BTN_R 3
#define LED_RED   4
#define LED_GREEN 5

void setup() {
  pinMode(STEP, OUTPUT);
  pinMode(DIR, OUTPUT);
  pinMode(ENA, OUTPUT);
  pinMode(BTN_L, INPUT_PULLUP);
  pinMode(BTN_R, INPUT_PULLUP);

  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);

  digitalWrite(ENA, LOW);  // Enable active LOW
  digitalWrite(DIR, LOW);
  digitalWrite(STEP, HIGH); // idle HIGH for CA

  // Anfangszustand: Motor still -> grün an, rot aus
  digitalWrite(LED_GREEN, HIGH);
  digitalWrite(LED_RED, LOW);
}

void loop() {
  if (digitalRead(BTN_L) == LOW || digitalRead(BTN_R) == LOW) {
    // Motor läuft -> rote LED an, grüne LED aus
    digitalWrite(LED_RED, HIGH);
    digitalWrite(LED_GREEN, LOW);

    // Richtung setzen
    if (digitalRead(BTN_L) == LOW) digitalWrite(DIR, LOW);
    if (digitalRead(BTN_R) == LOW) digitalWrite(DIR, HIGH);

    // Ramp: von langsam zu schnell, solange Taster gedrückt
    for (int delayUs = 2000; delayUs >= 200; delayUs -= 50) {
      if (digitalRead(BTN_L) == HIGH && digitalRead(BTN_R) == HIGH) break; // losgelassen
      stepOnce(delayUs);
    }
    // If still pressed, hold a high-speed constant
    while (digitalRead(BTN_L) == LOW || digitalRead(BTN_R) == LOW) {
      stepOnce(150); // high speed step (150 us spacing)
    }
  } else {
    // kein Taster: Motor still -> grün an, rot aus
    digitalWrite(LED_GREEN, HIGH);
    digitalWrite(LED_RED, LOW);
    delay(10);
  }
}

void stepOnce(int spacing_us) {
  digitalWrite(STEP, LOW);
  delayMicroseconds(50);
  digitalWrite(STEP, HIGH);
  delayMicroseconds(spacing_us);
}