I have a Bipolar Stepper Motor (12V, 350mA, 28oz-in NEMA-17) and would like to run it in the highest resolution (Sixteenth Step) with the A4988 Driver. According to multiple sources I read I need to "put 5V" to the MS 1,2,3 pins. What does this mean/How can I achieve this ?

Do I need to hook up the MS 1,2,3 to the digital pins of the Arduino and write Digital High. Or do I need to hook all of them to 5V together ? And should the code look like this ? Is this safe/good pratice ?

int MS1Pin = 8;                 // Set MS Pins
int MS2Pin = 9;
int MS3Pin = 10;  

void setup()
  pinMode(MS1Pin, OUTPUT);      // sets the digital pin as output
  pinMode(MS2Pin, OUTPUT);      // sets the digital pin as output
  pinMode(MS3Pin, OUTPUT);      // sets the digital pin as output

void loop()
  digitalWrite(MS3Pin, HIGH);
  digitalWrite(MS2Pin, HIGH);
  digitalWrite(MS1Pin, HIGH);
<<MY CODE here>>


Sorry for these beginner questions, I just don't want to fry the Chip and this to work.

Thank you.

1 Answer 1


You can drive the MS pins from the Arduino if you want, but there is no need. You can just hook them all up to 5V.

Have you seen this page, there seems to be load of details that you might find relevant. https://www.pololu.com/product/1182


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