Using Stallguard on Jackpots

[Stoli]

I want to play around with the stallguard feature of the TMC2209 drivers but I need clarification about the physical setup. On JP1, it looks like I need to run a jumper from the DIAG pin on the 2209 to one of the GPIOs on the limit switch input rail. Can somebody confirm this? And, if that is true, how is this handled on the JP3?

Cheers

[jeyeager (Jason Yeager)]

Stallguard is finicky. You can do it on a JP1 but I don’t think you can on a JP3.

Here is my experimentation with it;

Catching missed steps and stopping

I almost gave up on this a few times. I’m still not sure that we’ll be able to set the threshold to make this viable, but here’s a working proof of concept. I’m getting good info now without needing to hook up a computer. I reduced the auto-reporting interval and enabled debug messages (which you’ll want to set back to “Info” when done): $Report/Interval=100 $Message/Level=Debug I have a wire running from the diag pin on the X stepper driver to the signal pin on gpio 39. For config, I set …

[Stoli]

Thanks Jason. Great info as usual. I am pondering introducing a homing feature on the PolarGraph but since it is not feasible to have physical limit switches, I was thinking about using lasers and photo diodes. I just wanted to use stallguard to prevent the gondola from being ripped apart in the event that the laser switches malfunctioned. Yeah … too much time on my hands.

[vicious1 (Ryan)]

@Stoli

I want to play around with the stallguard

For homing or missed steps? If it is for homing, it is not accurate enough for repeatable use (like CNC Routers), for your polargraph, if you are able to tune it, it is good enough for “rough” homing.

@Stoli

On JP1, it looks like I need to run a jumper from the DIAG pin on the 2209 to one of the GPIOs on the limit switch input rail.

If you were to try this I would probably use the module port for the raw IO.

[Stoli]

Thanks Ryan. Does the JP3 hardwire the DIAGs to GPIOs?

[jeyeager (Jason Yeager)]

I agree this is likely viable for homing in your case.

I’m pretty sure they were made accessible in an early JP3 design but deemed not useful (including from my input) so it was removed.

[Stoli]

I really just want to use it for protection, especially during homing, but during running as well. Is there a schematic of the JP3 somewhere? I could swear I looked at one for the JP1 at one time, but I can’t find that either.

[vicious1 (Ryan)]

Jackpot3 CNC Controller - V1 Engineering Documentation , source files for the JP3. Similar link for the 1.

pin 15, is not used, but I suppose you could solder to it.

[Stoli]

Thanks. Good to know.

Cheers

[vicious1 (Ryan)]

@Stoli

I really just want to use it for protection, especially during homing, but during running as well.

Stallguard is way too complicated for all of that. Just lower your drive current. Lower it until you skip steps (probably much lower than you think), then raise it 10%. You can even tune lower accels to use lower current.

[MakerJim]

@vicious1

pin 15, is not used, but I suppose you could solder to it.

Yep, it would be a white wire modification to try and use it on JP3 just as it was a jumper wire on JP1