Great discussion, a lot of things to consider, so here’s my point:
CM4
I’am a big fan but sadly, we’ve missed it. Mostly because of its shortage BTW.
It’s still hardly findable in some countries and quiet expensive if you go for 8Go + Wifi (85€ at Berrybase de)
It’s an “old” design now and a bunch of alternatives are on the market.
CM5
Wait and see IMHO because
Raspberry Pi 5
itself introduce many nice features (PCIe lane, multichannel I2S, new RP1 southbridge) wich are closely related to mainline kernel evolution (*).
It’s the base of choice for exploring all these novelties.
Keep it simple
@stojos Zynthian mini approach is very inspiring in the developper’s POV: cheap and easily hackable for experimenting
and backward compatible
This is software and hardware related:
- of course Zynthian should continue to work headless
- considering the V4 layout (4 encoders + 4 buttons 3.5 inch SPI display) as the “de facto” standard
- V5 as the “extended” version
- add only features that are Raspberry Pi 5 related
(*) Kernel versions
Oram is on 6.1.62-v8+, RaspberryPi is working on 6.6 branch, Linus latest stable is 6.8.4 and current mainline is 6.9-rc3.
I think it’s good practice to keep at least Zynthian’s devel branch as close as possible from RasperryPi default Github branch (6.6.y) for working on the Pi 5 and also because it will benefit to
Porting Zynthian on other platforms
They are a bunch on the market, in different formats (SOM, “zéro” sized SBC, credit card SBC,…) with different CPU.
They mostly all can run a debian bookworm system with a recent kernel.
Example here for OrangePi boards: