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High-Power Stepper Motor Driver 36v4 pins mislabeled

Hi, Am I crazy, or is the silkscreen text for the STEP and DIR pins reversed?

Hello.

The STEP and DIR pins should be correct. You can actually verify this by following the traces on the top-side of the board and checking the DRV8711 datasheet to reference the pins they are connected to:

That datasheet is available under the “Resources” tab of the High-Power Stepper Motor Driver 36v4 product page. Are you having a problem with those pins?

Brandon

Hi Brandon, As far as I know everything is working great. The stepper motor seems to be doing exactly what it should be doing. Here is a link that I hope you can open https://photos.app.goo.gl/FNyMPvUNj9XnDn2A6 that shows what it is like when I pulse the DIR pin, and when I pulse the STEP pin. I think the result from pulsing the DIR pin is much better. Maybe I have the stepper motor connected wrong?

Here is some more information. When I use:

hpsd.step();

instead of:

digitalWrite(HPSD_STEP_PIN, HIGH);
digitalWrite(HPSD_STEP_PIN, LOW);

The motor works exactly the same. As I would expect it to work. Remember, my HPSD_STEP_PIN is actually connected to the DIR pin on the board.

Thank you for the additional information. Could you try tying the DIR pin low while you are sending your signal to the STEP pin to see if that changes anything?

Brandon

Hi Brandon,

When I tied DIR low and pulsed STEP the motor worked perfectly.

Thanks for trying that. We were able to reproduce the behavior you are getting as well. The STEP and DIR pins on the driver are pulled down internally on the chip, but evidently, the pull-downs are not strong enough (around 100k) to prevent noise from interfering. If you only want motion in one direction, you can leave DIR tied to GND or 5V.

Brandon

I’m glad you see the same thing, and it’s not just my board acting weird. I’m setup to use the setDirection() method for direction changes, and that works fine with the DIR pin tied to GND. Thank you for looking into this. I prefer using the STEP pin for pulsing the motor. It was strange to use the DIR pin as I was before.

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