Support for RP2040?

Th0mpy

Happened to notice in Github today that there's a new repository for RP2040. Are there plans to add support for the RP2040 as a CAN-Connected Duet controller? I suppose it'd be similar to a Sammy-C21. Drooling at the possibility

T3P3Tony

@th0mpy its under investigation!

zapta

There are even controllers that are based on the RP2040.

https://www.tomshardware.com/news/raspberry-pi-rp2040-3d-printer-control-board

o_lampe

@zapta
Without CAN-FD expandability it's a dead end.
It comes with 4 drivers and a fancy heatsink. The heatsink wouldn't be neccessary with propper board layout, but it sells

I'd like to see a RasPi-Hat with CAN-FD and some headers for external driver modules.

zapta

@o_lampe said in Support for RP2040?:

Without CAN-FD expandability it's a dead end.

It's a low cost board ($25) that was designed to be attached to Raspberry Pi for printers such as Voron V0 that don't have too many steppers and use Klipper. It's a nice looking little board.

I did a project with the RP2040 and it was a pleasure using it. Intuitive design and API and great documentation. Didn't have to struggle with it as I do with other MCUs.

pixelpieper

@o_lampe it doesn't have dedicated CAN hardware, but it does have programmable GPIO (PIO) which can be used to implement CAN, offloading at least some of the processing into a sequencer like state machine. There is still a need for the processor to take care of some of the package handling, but since we have two cores it's not that bad...

o_lampe

@pixelpieper
That's great to hear! I knew the state machines were good for something...
I just read the github readme and I'm not sure if it's CAN-FD? It mentiones Can2.0B ?

dc42

@o_lampe we have implemented a subset of CAN-FD on the RP2040 in the 3.5-dev branch of project Duet3Expansion. It's still experimental because we need to stress test it in a large system to make sure it's reliable enough.

o_lampe

@dc42
...and does that mean, with a RP2040, we wouldn't need the CAN-transceivers? AFAIK, they are (were?) hard to get because car industry has such high demand of it.

dc42

@o_lampe you do need the CAN transceivers. They should have low propagation delay because we can't do transmitter delay compensation on the RP2040. And yes, the MCP2542 CAN transceivers that we use on Duets and recommend for the RP2040 are hard to find at present, however the SOIC version is currently available from Microchip Direct.