Hi. I have been using le potatos to run klipper on my 3d printers for about a month now and they have been working fantastic.
Unfortunately, I have just encountered a small issue I am hoping to fix. When I tried to use a le potato for a voron build, the le potato did not see the attached pico/ rp2040-based devices (a picobilical and an skr pico MCU) on power up. Pressing the reset button on each 2040 board then allowed them to show up to the le potato (using lsusb) and work without issue. Curiously, this is somewhat well known issue with raspberry pi 4’s, but that does not effect raspberry pi 3’s at all. My issue was actually worse using a rpi 4, because the pico’s would not even allow the rpi4 to boot unless reset, while the libre booted all the way and just never showed the usb devices. I was someone hoping might know of a work around for getting the le potato to see the rp2040’s without resetting them. The issue appears regardless of how the le potato is powered (wired to stepdown converter then printer power supply, or powered via a canakit pi3 adapter. Thanks!
Below are some threads discussing the bug in the rp2040:
This is probably due to how the RP2040 MCU code is operating. It enumerate once and does not enumerate again unless the hardware is reset. That’s where the fix should go. There’s no way to reset power to the RP2040 from the Le Potato without turning the 5V regulator for USB and HDMI off. If your application does not use HDMI, you can manually turn off the regulator and turn it back on and the RP2040 should enumerate.