Category: General LinuxCNC Questions
Best bang for buck will be a RPi5 (if you didn't have a RPi5 I'd suggest an ex corporate PC) and either a Mesa Ethernet (preferred as you are not locked into a single platform)or SPI card. SPI & Mesa is supported on the RPi5 by the hm2_spix driver.
There are some other projects floating around Linuxcnc-RIO, but at the end of the day the Mesa cards are solid, well supported and don't look like disappearing soon.
Speaking from experience, regarding "roll your own" external motion cards, carefully work out a costing, sure the base FPGA card maybe cheaper than a Mesa card, but then you have to factor in all the other bits & bobs bring that up the same feature set.
Now I had a couple of Spartan FPGA dev boards floating around so adapting the Mesa SPI firmware and designing a couple of PCB's wasn't a great cost........but having to buy the parts to populate them was a different story. Getting a Mesa board to Australia is about $100 dollars just for postage alone last time I checked. To tell the truth it just started out as "can I get the firmware to run" then it snowballed.
I'm not trying to put you off but just some food for thought. Another point, delving into cnc is not cheap, so pricey can be kind of relative.
Mesa isn't a cult, it works, works well, is well supported by not only end users but by Pete from Mesa........who was kind enough to help me with a few questions regarding the project mentioned above. If my personal circumstances would allow it I'd be buying a few more Mesa cards to run my Lathe. The mill is fully equipped.
