PCB trouble shooting help

[rjbutler]

I flashed the ESP32 and set it up, built the PCB and tested everything out. It all was working on the bench so I closed up the case, put it on the bike and plugged it all in. I hit the shifters and it turned the resistance knob. Great! I did it a couple more times, and it stopped. The blue LED went out and the red LED was on solid. I can no longer connect to the ESP32, even over USB with the PCB removed from the case.

Any suggestions before I try to de-solder it and remove the ESP32? I thought maybe the twisting had caused a short, but everything still looks good. Solder connections look good too.

I'd start over, but it's hard to find all the parts. Is there an alternative to the TMC2225 (2208? 2226? I don't know enough to know if they are drop in replacements). And the RECOM part is also hard to find.

Thanks

[doudar]

I believe a 2208 step stick should be a drop in replacement but I haven’t personally tried it.

I wonder if it’s a possible infant mortality issue on the esp32? Normally they either work or they don’t. I’ve never experienced one that worked for a short time only.

Make sure that none of the legs from the tmc are touching the back side of the esp32 and that your power supply is less than 24v dc.

Try to re-flash the esp32 as well. Maybe the entire memory was corrupted somehow.

The only other thing I can think of is to make sure the wires didn’t get pinched when you closed the case and that the stepper motor wire is completely attached and good. I’ve had the TMC driver lockup an esp32 a couple of times and removing the stepper motor cable fixed the issue. If it works with the stepper motor cable disconnected, make a new cable and try again.

And maybe triple check your power supply for voltage and amperage. I’ve had some of the cheap Chinese supplies with voltages way outside of spec and amperage much lower than labeled.

Have fun and keep us all up to date!

[doudar]

Yes

[doudar]

Thinking back, I have had a TMC driver fail which prevented the ESP32 from booting. It will be interesting to hear what you determine happened.

[rjbutler]

I ordered some TMC2208’s. Maybe I’ll be able to salvage the recom.

[rjbutler]

I think you may be right, @doudar. I pulled the ESP32 and it does boot OK off the board. I'm getting 5v on the RECOM, so I assume that's OK so probably the TMC2225? I did test the power supply and it's outputting 25v. I assume that's OK? Or should I buy a new one? Thanks for the help.

[doudar]

Both the recom and the tmc2225 (I didn’t look up the 2208) are good to over 30v.