ascott

When you say “motor 1 pinout” is that J17 such that I could attach a http://www.pololu.com/product/1182 to it and get the drive both X motors?

Yep, you got it.

If so, would the fact that you are using two different drivers (one on the TinyG and the Pololu part) be an issue?

I’m not sure about this – maybe Alden can answer whether there are any problems mixing and matching motor drivers. One issue that I see is that there is no way to set the microstepping for the Pololu driver from the TinyG, so you would have to make sure that the Pololu driver’s microstepping (set either in hardware or from some other device) matches the TinyG’s Motor1 microstepping (set in software, and reset to default any time you do a firmware upgrade). If the microstepping for the drivers don’t match, they’ll drive the X-axis motors at different rates. Yuck.

Oh! To get around the mismatch problem, I suppose you could just use TWO of the Pololu drivers connected to J17, and leave the TinyG’s Motor1 driver unconnected. Note that in order to get accurate positioning, you’ll still have to make sure that the microstep setting ($1mi) in TinyG matches your external driver configuration.

Now that I think about it, I think doubled external drivers is the better way to go. I haven’t actually tried running a dual motor axis yet, though, so you may want to get additional input before you go shopping 🙂

• This reply was modified 10 years ago by ascott.