const int dirPin = 2;     
const int stepPin = 3;    
const int enablePin = 4;  
const int potPin = A0;    
void setup() {
  pinMode(dirPin, OUTPUT);
  pinMode(stepPin, OUTPUT);
  pinMode(enablePin, OUTPUT);
  digitalWrite(enablePin, LOW);  
  Serial.begin(9600);
}
void loop() {
  int potValue = analogRead(potPin);
 int stepDelay = map(potValue, 0, 1023, 100, 2000);
  if (potValue > 512) {
    digitalWrite(dirPin, HIGH); 
  } else {
    digitalWrite(dirPin, LOW);  
  }
  digitalWrite(stepPin, HIGH);
  delayMicroseconds(500);       
  digitalWrite(stepPin, LOW);
  delayMicroseconds(stepDelay);  
  Serial.print("电位器值: ");
  Serial.print(potValue);
  Serial.print(" | 速度: ");
  Serial.println(stepDelay);
}