How to configure Klipper on Octopus using CAN_bridge_mode

[DanPin]

My Configuration: BTT Pi, Octopus v1.1, EBB2240

I got Klipper loaded and working with the MCU path using serial: /dev/serial/by-id/usb-Klipper_stm32f446xx_050038001350535556323420-if00.
Then I wanted to reconfigure Klipper on Octopus to enable the CAN port so I could talk to the EBB2240.
When I did menuconfig I set communication for CAN_BRIDGE. Which seems to work because I can see the CAN bus when lsusb.

HOWEVER, the /dev/serial directory is gone and I can't talk to the octopus board any more over USB (Fluidd won't connect)
Seems like I need: serial: /dev/serial/by-id/usb-Klipper_stm32f446xx_050038001350535556323420-if00
in addition to parameters for CAN.

I am not understanding how to enable the CAN adapter on Octopus.

Any explanation would be very helpful

 

[Spice_King]

I believe you need to address it as if it's a CAN device, not a serial one. CAN_BRIDGE makes it put up a CAN interface with the MCU being a node on the bus, though only virtually as CAN frames for it do not show up on the actual CAN network.

CANBUS - Klipper documentation

www.klipper3d.org

 

[DanPin]

I need to read that doc a couple of time....
Still confused because:
printer.cfg=
[mcu]
## Obtain definition by "ls -l /dev/serial/by-id/" then unplug to verify
##--------------------------------------------------------------------
serial: /dev/serial/by-id/usb-Klipper_stm32f446xx_050038001350535556323420-if00
#canbus_uuid=43f06262c86
restart_method: command

IF I swap to canbus_uuid, how do I use Katapult ( for the -d option)
python3 ~/katapult/scripts/flashtool.py -f ~/klipper/out/klipper.bin -d WHAT_DEVICE

Dan

 

[shiftingtech]

serial: /dev/serial/by-id/usb-Klipper_stm32f446xx_050038001350535556323420-if00
#canbus_uuid=43f06262c86

Seems very wrong that you have the serial line enabled, and the canbus_uuid line commented out, if the board is really configured in can-bridge mode.

As for "WHAT_DEVICE" well...each device has a uuid. Give flashtool the uuid of the device you are actively trying to flash! (I assume the toolhead board)

 

[DanPin]

With what several very kind forum members (including shiftingtech) have explained, I believe I need to do the following.:
For flashing Klipper to each MCU, I need to specify the comm's method for "that particular MCU" in menuconfig
So Octopus is serial and EBB tool head is CAN-bus.
Then in the config file there is a section for each MCU.

Bottom line, if I flash Klipper to the Octopus with CAN comms, the Pi can't talk to it

 

[Spice_King]

As said before, CAN bridge means it's no longer a serial device, but a CAN one. Once flashed to a firmware running as CANBus bridge, you need to configure it as if it's a CAN Bus device as it no longer emulating a USB serial port but a CAN interface now. You can still see the USB connection with lsusb, assuming you have it connected with USB. ls -l /dev/serial/by-id/ only shows serial ports, not USB devices.

 

[shiftingtech]

There's a distinction here between flashing the octopus as a CAN device, and as a CAN-BRIDGE device. In the latter case, klipper can talk to it, however it will be using a canbus uuid to do so, not a serial id. (Despite the physical link still being usb. Can-bridge is just the weird exception to every rule you come up with, basically)

 

[DanPin]

OK, I understand what you are saying,,,,but it really seems strange.
Based on your post, if the Octopus is in "CAN-Bridge" mode, and my EBB is connected to Octopus as a CAN device, everything coming over the USB-C from the Pi will be using a CAN_UUID for BOTH the Octopus and the EBB.

I will be working on this today and will try it.

Thanks,
Dan

 

[DanPin]

Got the basics working....went with a BTT U2C adapter for overall simplicity...thanks for all the help...it was a good education.

 

[shiftingtech]

OK, I understand what you are saying,,,,but it really seems strange.
Based on your post, if the Octopus is in "CAN-Bridge" mode, and my EBB is connected to Octopus as a CAN device, everything coming over the USB-C from the Pi will be using a CAN_UUID for BOTH the Octopus and the EBB.

I will be working on this today and will try it.

Thanks,
Dan

well, there would be one CAN UUID for the octopus, and a different one for the EBB. but yes, basically.