Category: Installing LinuxCNC
As far as my testing has shown, on my cobbled together 7c81 clone SPI works on the RPi 5.
I received my RPi5 around Nov\Dec 2023 and can't say I've noticed any hardware issues. Booting from a NVME drive has shown no issues, I've run octoprinter on it, once again no issues.
Speed wise even when running via a SD card is night and compared to my RPi400, which has a slightly faster CPU than the RPi4. Actually to be fair it is a bit of a beast.
No trouble building Linuxcnc packages, even with 2 cores isolated, tho I suspect this may not be needed when connected to a Mesa board.
Bang for buck a PC from the last ten years is far better value.
Personally I'm still undecided whether to use my clone with an EPP interface with a PC or with the RPi5 via SPI.
To tell the truth I'm in 2 minds whether I actually want to CNC the lathe, the only reason I started to convert it is the AUD $600 to get hold of a new screw, maybe it would be worth it, if only to have one of the few Myfords with a leadsrew that isn't worn.
Back to topic.
Whilst the RPi is able to run Linuxcnc not a lot of info for the official Raspberry Pi foundation images are applicable, as it is only really the RPi kernel sources that are used, needed for use of loading overlays, the rest is pulled from Debian arm64 repos. Config.txt must be edited to enable the SPI interfaces. And Linuxcnc will need building from source to have the hm2_spix driver. Last time I looked the pre built packages pre dated the new driver.
Re Tommy's comment regarding a small SBC controlling a large CNC machine, how would you feel riding a bike at 220-240 kph ( on a race track of course) that's ecu is controlled by a Motorola microcontroller ? Cos that's the brains used in a lot of Ducati's and Moto Guzzis around 2000 vintage. Very hackable, very easy to download the operating code off and disassemble. Even a fully unqualified shit kicker like myself was able to do, the one and only time I did anything with C Sharp.
