Hi, so on printer the biqu bx use board on print head this one is no longer available and mind broke this week so i will replace it by the hermit crab v2 can bus, but i start to check how configure the motherboard and on list dont find the right port, on drawing the CAN came from PB6/PB7
on klipper configurator this is the list
(X) CAN bus (on PB8/PB9)
( ) CAN bus (on PB5/PB6)
( ) CAN bus (on PB12/PB13)
( ) CAN bus (on PD0/PD1)
( ) CAN bus (on PB0/PB1)
( ) CAN bus (on PD12/PD13)
( ) CAN bus (on PC2/PC3)
( ) CAN bus (on PH13/PH14)
so how is the right config to use CAN on this board
Normally, when a board designer specifies a CAN Bus port, they are going to the MCU’s pin mux definitions and selecting pins that have the CAN function.
When I look at the datasheet for the STM32H743, for PB6/PB7 I see:
(I think CAN HAT is better in general, because there would be no USB or MCU at all)
(Like RPI → SPI → CAN: https://www.waveshare.com/wiki/RS485_CAN_HAT)
(Instead of RPI → USB → MCU → CAN)
Thanks you, for your reply, so it comfirm what i see, on board V3 they make change they use PB5/PB6, so for me the best way i use the U2C
about the klipper configurator i need to change what to use the U2C?
The U2C attaches to the Pi. I think it is “plug and play” on systems running a recent kernal. Check the documentation from Bigtree.
The toolhead (hermit crab) then connects to the U2C directly. The mainboard MCU is no longer involved in communicating with the toolhead. No need to CAN pins on the mainboard.
You’ll need to find the UUID for the toolhead and put that into printer.cfg.
You’ll have to edit all the pin id’s for everything that connects to the toolhead MCU
Make sure the board is indeed flashed with the correct firmware and settings, especially CAN pins and speed. Flash in bootloader (BOOT button on the board) mode using make flash FLASH_DEVICE=2e8a:0003. After setting the board into bootloader mode, verify with lsusb befor flashing.
So update find the problem the connection on hermit the cable is bad if i move it i loss the connection so now try to fix it to get printer ready and not loss the connection