M-S Motor X15.xxx

hi,

I need some help with my Stepper Motor.

I try do control it with my Arduino Uno and the Easydriver, but until now I can't do a whole round(360).
Do they have an internal stop?

http://www.langtech.com.cn/web_en/others/about_mc.htm

Arduino Code:

int STEP = 2;    
int DIR = 3;   
int MS1 = 5;        
int MS2 = 6;       
int SLP = 7;       


void setup (){              
  pinMode (STEP, OUTPUT);
  pinMode (DIR, OUTPUT);
  pinMode (MS1, OUTPUT);
  pinMode (MS2, OUTPUT);
  pinMode (SLP, OUTPUT);  
}

void loop (){
  digitalWrite (MS1, LOW); 
  digitalWrite (MS2, LOW);  
  digitalWrite (DIR, LOW);
  digitalWrite (SLP, HIGH);
  

  for (int i=1; i <= 12; i++){   
    digitalWrite (STEP, HIGH);
    delayMicroseconds (500);
    digitalWrite (STEP, LOW);
    delayMicroseconds (1000);  
  }
  
  digitalWrite (DIR, LOW); 
  for (int i=1; i <= 12; i++){   
    digitalWrite (STEP, HIGH);
    delayMicroseconds (500);
    digitalWrite (STEP, LOW);
    delayMicroseconds (1000);  
    
  }
  
  digitalWrite (SLP, LOW); 
  delay (1000);
  digitalWrite (SLP, HIGH); 
  
}

They have an internal stop.

Thanks.