A4988 Stepper Driver

// Canonical A4988 stepper driver example for Arduino Uno
// Moves a NEMA17 stepper motor back and forth using STEP/DIR.

const int STEP_PIN = 2;
const int DIR_PIN  = 3;
const int EN_PIN   = 4;

// With MS1/MS2/MS3 tied LOW, the driver is in full-step mode.
// Adjust this if you change microstepping wiring.
const int STEPS_PER_REV = 200;

void stepMotor(int steps, bool direction, int stepDelayMicros) {
  digitalWrite(DIR_PIN, direction ? HIGH : LOW);
  delayMicroseconds(5); // Direction setup time

  for (int i = 0; i < steps; i++) {
    digitalWrite(STEP_PIN, HIGH);
    delayMicroseconds(stepDelayMicros);
    digitalWrite(STEP_PIN, LOW);
    delayMicroseconds(stepDelayMicros);
  }
}

void setup() {
  pinMode(STEP_PIN, OUTPUT);
  pinMode(DIR_PIN, OUTPUT);
  pinMode(EN_PIN, OUTPUT);

  // A4988 enable is active-low.
  digitalWrite(EN_PIN, LOW);

  Serial.begin(9600);
  Serial.println("A4988 stepper driver demo starting...");
  Serial.println("Motor will rotate one revolution clockwise and counterclockwise.");
}

void loop() {
  Serial.println("Clockwise");
  stepMotor(STEPS_PER_REV, true, 800);
  delay(1000);

  Serial.println("Counterclockwise");
  stepMotor(STEPS_PER_REV, false, 800);
  delay(1000);
}