question

1. Powered USB hub is not essential as listed adapters are not that power-hungry. But I prefer powered hubs as RPI's own power adapter can be smaller and not lift regulator temps in the RPI board.

2. Did you find a ready-to-go solution to RPI4? I have been reading threads, and looks that there is not yet a ready ported solution for RPI4.

3. Don't have personal experience with CANbus adapters as proposed to use Victron GX-hardware when CANbus is needed. With Cerbo, you can have a cheaper and more reliable setup as no need to use the adapters.

i was thinking of buying one of these to CANBUS to my Batrium

https://thepihut.com/products/2-channel-isolated-can-hat-for-raspberry-pi

My RPI 4 is up and running Venus GX. Getting a 7" touch screen was a slam dunk with the help provided here on this forum:

https://community.victronenergy.com/questions/65414/venus-os-raspberry-4-5-mpi5001-calibration-touchsc.html

I found a link to the RPI4 image:

https://updates.victronenergy.com/feeds/tmp/venus-image-raspberrypi4-20191124183952-v2.40~42.rootfs.wic.zip

and more info in this post:

https://community.victronenergy.com/questions/25666/venus-on-raspberry-pi-4.html

I had no luck with a CANbus interface I bought on Amazon:

https://www.amazon.com/gp/product/B07FY4YLPL

So this is on the DO NOT USE list.

There are many on the list here:

https://github.com/victronenergy/venus/wiki/RaspberryPi-CAN-Interfaces

It largely depends on whether you what a hat board or a USB interface.

I went with the CANable USB because it's inexpensive. I picked the isolated version to avoid issues.

Rob Duthie also is working on "Stetson" an adapter board with most of the interfaces you'd find on Cerbo, plus a handful more. But he's waiting on Venus OS RPI4 support for the newer v1.4 board which currently doesn't boot.

Beware of some of the cheaper CAN interfaces on the net. Some of the CAN/SPI interfaces use 5V for the SPI levels, this will damage the pi. However, wiht care these can be modified to use 3.3V for the SPI - though the drive to the CAN Buffer chip needs to remain at 5V. If you are up to some delicate hacking, these can be acquired for $35 or so. Does not apply to CAN/USB interfaces.