// left sensor 

#define LEFT_SENSOR = A0; 
#define RIGHT_SENSOR = A1; 

// Left motor
#define LEFT_DIR  12
#define LEFT_STEP 13

// Right motor  
#define RIGHT_DIR 4
#define RIGHT_STEP 3

void setup() {
  pinMode(LEFT_DIR,  OUTPUT);
  pinMode(LEFT_STEP, OUTPUT);
  pinMode(RIGHT_DIR, OUTPUT);
  pinMode(RIGHT_STEP, OUTPUT);

  pinMode(LEFT_SENSOR, INPUT);
  pinMode(RIGHT_SENSOR, INPUT);

  Serial.begin(9600);
  Serial.println("Motor test running");
}

void stepMotor(int stepPin, int dirPin, bool forward, int steps) {
  digitalWrite(dirPin, forward ? HIGH : LOW);
  for (int i = 0; i < steps; i++) {
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(800);  // speed — lower = faster
    digitalWrite(stepPin, LOW);
    delayMicroseconds(800);
  }
}

void loop() {

  left_value = analogRead(LEFT_SENSOR); 
  right_value = analogRead(RIGHT_SENSOR); 
  
  stepMotor(LEFT_STEP, LEFT_DIR, true,  400);  // forward
  delay(500);
  stepMotor(LEFT_STEP, LEFT_DIR, false, 400);  // backward
  delay(500);
}