Bigtreetech BTT Pi and CAN-Toolhead (e.g. SB2209) direct connection?

[martin77]

Hi all,

my current setup on Voron 2.4 R2 is without CAN: BTT Pi 1.2, Oktopus 1.1 and Stealthburner. Now I want to switch to CAN (and not wait until a cable gets broken).
The documented way is to use the Oktopus board as CAN bridge - I know. But: As the BTT Pi already has CAN Pins I am wondering whether there is a better way: Is it possible to connect SB2209 directly to the CAN pins on the BTT Pi?

Kind regards,
Martin

 

[thomasfjen]

Hi all,

my current setup on Voron 2.4 R2 is without CAN: BTT Pi 1.2, Oktopus 1.1 and Stealthburner. Now I want to switch to CAN (and not wait until a cable gets broken).
The documented way is to use the Oktopus board as CAN bridge - I know. But: As the BTT Pi already has CAN Pins I am wondering whether there is a better way: Is it possible to connect SB2209 directly to the CAN pins on the BTT Pi?

Kind regards,
Martin

To use the btt pi "canbus" pins you would need the u2c onboard module. It does not have native canbus support without that module. You can use the octopus in canbridge mode, but it can be troublesome as all mainboard communication is then "flowing" over canbus, that may too much for the btt pi too handle and results in timer too close errors.




Greetings Thomas

 

[martin77]

Well, I understood that like you, that I need a U2C module to use CAN bus. But I asked myself: Why? According to

this "small" board specifically designed for the BTT Pi is not connected to these CAN pins on the BTT Pi: It's connected to some part on the 40-pin-GPIO header. So...is there any purpose of the CAN pins? Or are they just for decoration?

EDIT: Oh, wait, now I see it: The BTT Pi has two connectors regarding CAN: And the small U2C board is plugged into the second connector plug. Ah, this is what it's used for.

Greetings,
Martin