LinuxCNC-RIO - RealtimeIO for LinuxCNC based on FPGA (ICE40 / ECP5)

Look forward to seeing how that goes, Tang Nano's are about 30 bucks AUD, two of them are still cheaper than any FPGA with a similar total pincount. I'm being selfish but that also means I stick with the same FPGA hardware for every machine I can possibly imagine making. 

Let me know if I can help with testing, I'm currently retrofitting my three machines to closed loop to the controller, so there's room for some hardware experimentation. 

if you have two (or more ) Tangnano, you can try it, you need the 'dev' branch and
2 free pins on each tangnano (RX / TX).
For short distance, you connect this pins direct (RX<->TX) or using RS485/RS422 converter for long distance.

Oh wait a minute, so you can have more than one extra FPGA? Alright then looks like I need to order some more Tang's.

yes, but please try it first, it's experimental !