const int coil1 = 9;
const int coil2 = 6;
const int coil3 = 3;
const int coil4 = 5;
void setup()
{
  // put your setup code here, to run once:
pinMode(coil1, OUTPUT);
pinMode(coil2, OUTPUT);
pinMode(coil3, OUTPUT);
pinMode(coil4, OUTPUT);
Serial.begin(9600);
}

void loop()
{
  // put your main code here, to run repeatedly:
digitalWrite(coil4, LOW);
digitalWrite(coil2, HIGH);
delayMicroseconds(1600);

digitalWrite(coil1, LOW);
digitalWrite(coil3, HIGH);
delayMicroseconds(1600);

digitalWrite(coil2, LOW);
digitalWrite(coil4, HIGH);
delayMicroseconds(1600);

digitalWrite(coil3, LOW);
digitalWrite(coil1, HIGH);
delayMicroseconds(1600);
}