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

www.aliexpress.com/item/1005001792842062.html

pretty good price

Until someone has reverse engineered them it's a bit of work.
And honestly once you add in the price of a carrier board and designed and produced interface boards it's starting to get a bit pricey.
Not that I'm against these projects, and ATM there is a good argument for them due to some MESA boards being hard to come by, also if you like tinkering they are great to spend a bit of time with.
And some of these boards do require some skill in soldering, specially when replacing chips on a .65mm pitch. Just replacing the chip isn't the whole story, you have to take into consideration your VCC so as not to take out the FPGA.
If you have the skill go for it, but you really need to do some research before jumping in.

Tho the LINUX-RIO project is a little easier as it does use off the shelf dev boards that are well documented and don't require board level mods. A simple 74LVC245 works well for the inputs for translating 5v signals to 3.3v signals. 74HCT540/541 work well for translating from 3.3v to 5v for outputs.

Oh and when dealing with ALiexpress you have to make sure you will get a supported board. As sometimes the adds get be a little unclear regarding the exact model.

the devboards were only an intermediate step,
we are in the process of building our own boards.

I want a modular board, so that I don't have to rebuild everything for every new function.

FPGAs that can be used completely with open source tools.

And a simple code base that I can understand, for example if something goes wrong in litex, I have no idea how to fix it.

It's also possible to use non OpenSource tools with RIO, here is a new video from TurBoss with an TangNano20K board and a his new UDP-Bridge:



I think RIO is a good platform to play around with FPGA's with a flat learning curve
and cheap accessible hardware.

If someone wants to operate a professional milling machine, it is better to use mesa anyway.

I really dig your philosophy. Simple open source tools.

The Olimex board is good (good price as well), apart from the pesky 1.27mm connectors.

I reckon a board based on a Lattice Ice40, with 74CBT3245 FET bus switches (or wider) so interfacing with 5v would be easier (maybe 17 pin ports so Generic BoB interfacing is easy). No RAM, maybe 1 or 2 LEDS for status. No fancy USB on board programming, just access to SPI for programming & comms.

little sensor example with RIO :

I have add a Water-Flow Sensor to my CNC:




config looks like this:

first step to integrate the Hunayang VFD into RIO

youtube.com/shorts/cMVN13VCYEs

only a test to check the modbus protocol , not sure if i should use a microcontroller between FPGA and the VFD or implementing the modbus direct into the FPGA.

added modbus to esp32 ?

yes, but only to understand the protocol and for testing the max485

VFD works now