I have venus os working on a raspberry pi with the usual CAN hat that gets recommended in order to speak to my pylontechs. Everything else is USB other than the CAN hat connection to the pylontech.
For “reasons”, I would prefer to migrate this to a VM on an existing proxmox server I have and drop the pi. The show stopper here is the CAN hat…
So I’m looking for USB options instead, there are a variety of “usb to rs485” options out there e.g. https://www.robotics.org.za/W17286?search=rs485&page=2 but obviously I’d prefer to have some kind of idea of what to buy instead of just blindly purchasing and then finding out it doesn’t work.
Does anyone know which if any of these have a chance of working? Or any experience/advice with this?
If you want to use the console port or RS485 connection, then unless you write your own driver, the answer is probably no.
Unless you use a CAN->USB device of some sort. There are a few slcan type devices cheaply available, and slcand is already available on Venus. In fact, the BMS-CAN port on earlier Cerbos is an slcan-based chip that sits on the USB bus (/dev/ttyUSB0), which is automatically detected and symlinked by udev. It should be possible to do the same thing, but you’ll have to hack the udev config a bit. Don’t ask me… I can figure it out if I absolutely have to, but I’m leaving it as an exercise for the reader.
You can also use an arduino with a CAN-bus shield, and then run slcan-compatible firmware on that, but that is bulky, expensive, overkill.
I seem to remember a 5USD device that did this, but I cannot find it anywhere now.
So something like this basically? (https://www.digikey.co.za/en/products/detail/seeed-technology-co.,-ltd/114991193/7387418) Or any such thing with the same chipset?
I’m okay with fiddling around with the OS a bit if need be, not scared of udev etc.
So as long as its something that is theoretically capable of working and not completely fighting a losing battle thats fine.
Found this https://community.victronenergy.com/idea/77971/venus-os-modification-scripts.html so it looks like the “canable” devices are a safe bet, maybe I’ll just grab one of those.
Nope. That Seeed device doesn’t look like it uses the slcan protocol.