有程序，想通过arduino和tb6600实现步进电机转动一定的圈数，需要知道什么，怎么改程序

#define PUL 9 //CLK
#define DIR 10 //CW

void setup() {
  // put your setup code here, to run once:
  pinMode(PUL,OUTPUT);
  pinMode(DIR,OUTPUT);
  Serial.begin(9600);  
}

void loop() {
  // put your main code here, to run repeatedly:
  
  digitalWrite(DIR,LOW); 
  for(int i ; i<=600 ; i++)
  {
  digitalWrite(PUL,LOW);
  delayMicroseconds(20);
  digitalWrite(PUL,HIGH);
  delayMicroseconds(20);
  }
  
​