I had the same problem trying to get a stepper to run with this chip.
I have wired I01 and I11 both to D2 on arduino and Phase1 and Phase2 to pins 3 and 4 respectively.
I succeeded with the following code:
#define I_pins 2
#define ph_1 3
#define ph_2 4
int DT = 1; // time delay between steps, speed of motor.
int NS = 50;
void setup() {
pinMode(I_pins, OUTPUT);
pinMode(ph_1, OUTPUT);
pinMode(ph_2, OUTPUT);
}
void loop(){
// Move the motor forward:
for (int i = 0; i < NS; i++) {
digitalWrite(ph_1, HIGH);
delay(DT);
digitalWrite(ph_2, LOW);
delay(DT);
digitalWrite(ph_1, LOW);
delay(DT);
digitalWrite(ph_2, HIGH);
delay(DT);
}
delay(1000);
// Move the motor backwards
for (int i = 0; i < NS; i++) {
digitalWrite(ph_2, HIGH);
delay(DT);
digitalWrite(ph_1, LOW);
delay(DT);
digitalWrite(ph_2, LOW);
delay(DT);
digitalWrite(ph_1, HIGH);
delay(DT);
}
delay(1000);