..
Anyway, I've ordered the faster controller - I'm not adverse to having a spare controller as it's a long way to my usual dark sky site if something fails...
You may run into another problem: your steppers may stall due to too fast stepping.
I have 1:5 reduction before worm (belt) and I can't go faster than ~75% of STM32 capability on one mount.
Here is the ‘finished’ board. Motors are working (tested via the white molex connection, not the RJ45 points) and so is the hand controller. I just need to print a case for the STM32 controller and add RJ45 connection terminals to the motors. It’ll be a few weeks before my scope is ready to mount these and can work out the final step counts, etc. I’ll post the complete setup then.
You may run into another problem: your steppers may stall due to too fast stepping.
I have 1:5 reduction before worm (belt) and I can't go faster than ~75% of STM32 capability on one mount.
I wouldn’t be surprised if you’re correct. I’m very much a beginner at electronics, but enjoy the tinkering.
Hi Scott,
Looks like your getting it all together nice.
I'm not sure if you got my message on the onstep forum, but I'm looking for three LV8729's if you have any to sell?
I’ve received additional feedback on the onstep forum (thanks Ash) regarding the STM32 flash mod and a 10k ohm resister is recommended rather than shorting the R3 resistor. I’ve not had trouble so far, but I’ll likely make the change this weekend.
For those who are interested in the STM32 Onstep controller, or were considering it but were concerned about its speed, there is a new microcontroller to replace the STM32 bluepill, called a the Robotdyn STM32F303 and it's apparently 2x faster. It's also plug n play if you want to upgrade your existing build.
Cost of the new driver on aliexpress is about $15 delivered compared to about $6 for the blue pill and there are no issues with having to short pins or solder on additional resistors. Link is below.
