Understanding the buildbotics controller

My first post here so please be kind. (Machine delivery in Jan/Feb 2021?)

Some background, I am a Mech Engineer who writes software for other engineers to use. So by my very nature I have to peel back the cover on the controller.

I came up with this link

So the center of the machine is basically a Raspberry Pi 3,that is a roomy with a TI’s DRV8711 that drives the steppers.

Reading through the article this info maybe a bit dated (Sept 2017) but these guys appear to be good at squeezing out performance

Besides the article I also looked at their Github site, again quite professional I particularly like this page

So lots of good information.



Thanks for the link. I was wondering if there was a way to make the stepper motors silent without reducing performance. Trying to draw a parallel with my 3d printer and the OF.

Hi Carl and Lynn,

i was wondering if you can help me connect some dots.

I have a touchscreen monitor by Acer T272HUL
after connecting the controller to that monitor using the HDMI and USB cables - i realized the touchscreen wasnt working.

i got in touch with onefinity support, i talked to folks on the fb page, i tried looking through forums - with little to no help so far.

Except for one.
i will share the link further below for you to check out.

the recommendation by these folks was that 1 step would fix that problem

add dwc_otg.speed = 1 to the file:/boot/cmdline.txt

the question is - how do i do that?
with your background - i was hoping you can guide me to make that change on the one finitiy controller and raspberry Pi board.

following is the thread if you’d like to look at it.
thank you again.



Wow where to start… first modifying the boot configuration of a machine can be a bit of black magic. I am not familiar with the actual Pi version being used so not sure where that file actually exists.

My concern is if you don’t know what you are doing it would be possible to effectively “brick” your controller. Is this risk worth a monitor?

If you are going to try this you will need to learn about things like:

  • Root Access
  • Editors such as Vi
  • System backups

That a lot of learning for an inexpensive monitor