1. /// 0111 1011 1101 1110 // input format for full step one phase ON
2. 
3. int in1 = 8;
4. int in2 = 9;
5. int in3 = 10;
6. int in4 = 11;
7.
8. int i = 0;
9. int freq = 200;
10.       unsigned long t_half =0.5*(1000000/freq);
11.
12.       void setup()
13.       { pinMode(in1, OUTPUT);
14.         pinMode(in2, OUTPUT);
15.         pinMode(in3, OUTPUT);
16.         pinMode(in4, OUTPUT);
17.       }
18.
19.       void loop() {
20.         delayMicroseconds(t_half);
21.         i=i+1;
22.         if (i >=4) {i=0;}
23.        switch(i)
24.        {
25.          case 0:
26.            digitalWrite(in1,LOW);
27.            digitalWrite(in3,HIGH);
28.            digitalWrite(in2,HIGH);
29.            digitalWrite(in4,HIGH);
30.          break;
31.          case 1:
32.            digitalWrite(in1,HIGH);
33.            digitalWrite(in3,LOW);
34.            digitalWrite(in2,HIGH);
35.            digitalWrite(in4,HIGH);
36.          break;
37.          case 2:
38.            digitalWrite(in1,HIGH);
39.            digitalWrite(in3,HIGH);
40.            digitalWrite(in2,LOW);
41.            digitalWrite(in4,HIGH);
42.       break;
43.       case 3:
44.            digitalWrite(in1,HIGH);
45.            digitalWrite(in3,HIGH);
46.            digitalWrite(in2,HIGH);
47.            digitalWrite(in4,LOW);
48.       break;
49.       }
50.      }