Extruder overheats even when Klipper can't communicate with board

[paul2024]

Basic Information:

Generic Printer
Octopus Pro 1.0
klippy (2).log (2.5 KB)

Describe your issue:

I hooked up a raspberry pi 4 to the USART2 in the octopus board and compiled the firmware according to the settings for the chip on my board (STM429), then loaded the firmware on the board just fine.

When I turn the board ON the pi starts and mainsail OS is ready, but Klipper can’t find the printer, which is another issue I am going to look at but then I notice the extruder is heating up non-stop and I have to shut it down.

How come the extruder heats up even if Klipper hasn’t loaded the printer.conf file?

[EddyMI3D]

Either you have some wiring issues or the board is broken.

[paul2024]

I see, the board was fine with the marlin firmware though, will double check the wiring but it’s actually pretty simple to hook up the pi to the uart.

[paul2024]

Just ran a test here:

1 - Unplugging the raspberry makes no difference, still heats up.
2 - Flashing marlin fixes it.

Funny how I had Klipper running via USB on a Linux computer without any issues, the only thing that I changed on the firmware to load the raspberry was the USART2 connection, but the pi powers on and works fine, still puzzled why that change on the menu build would cause the extruder to heat up to the extreme.

[paul2024]

Never mind, I chose the wrong USART2, there are two of them… Should have been PD6/PD5.