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

@Dave3891, but you can send me the files (pinouts + board-image),
than i can create one for you

A small request to everyone who uses Rio.

I hate telemetry in software, I don't want it in other software and I don't build it into mine either!

The downside, however, is that I never know if the stuff is any use at all.

I'm always happy when someone writes here that they've built a custom board, or when I happen to see pictures or videos online of boards I don't know yet.

An open source programmer usually only sees the problems and errors that users have, but very rarely reports of success.

So I would be very happy if you could give me a little feedback.

And even those who don't use it can say what they think is missing or what is stopping them from trying it out.

Best regards, Olli

I haven't had a chance to really give it a good go lately, other things have got in the way.
But I've found your project to be solid and though it doesn't really relate to your project, but when I came across it I was in a bit of a dark place and it gave me the will and drive to get active again.

First of all, thanks a lot for all the work you put into this project, it’s clearly helping a lot of users, especially when it comes to building and customizing configurations.

I’m currently using a Mesa 7i92m. While the standard firmware works fine, making configuration changes on it can be quite cumbersome. It looks like RIO could make things a lot easier.

Could you maybe share some guidelines or pointers on how to get it working on this board, or how to port it?

The biggest issue would be a driver for the ethernet chip.
The mesa firmware uses a softcore (think very basic CPU) and that runs assembly language program to do all the hard lifting.
Ollie's original aim was to not have a softcore so there was virtually no jitter. I pretty sure I have this right.
To get this done I really think Ollie would need a 7i92 to do this.
The 7c81 was a simple task as it already had SPI, the 7i90 would be easy as well.
The thing with the Spartan 6 it's picky regarding which pin is the system clock and which is the SPI clock. I had trouble with the 7c81 clone I was working as the pin used for the system clock was different on the dev board I was using to the original mesa one.

Now that is not to say Ollie could not do it. If he could that would be pretty awesome as I have a couple of the Ethernet chips the 7i92 uses. Microchip offers free samples of their products.

RIO now actually consists of two projects:

1. Configuration front end with HAL/INI generator

2. FPGA gateware generator


In Rio, there are now two ways to use a Mesa cards:

1. with RIO firmware/gateware (FPGA gateware generator)

Unfortunately, only those with an SPI interface. I will try again to build something that works with the MII chips when I get the chance, but it may take a while.

2. Original hm2 firmware (HAL/INI generator)
Still being tested. At the moment, only the 7c81 is supported, as I have this at home. Next will
be the 7i92.
This should actually support all cards, but in order to configure them correctly in the flow tool, you have to enter all pin positions into a file, which is simple but time-consuming.


I have already ordered a 7i92 clone from China.

The Ethernet chips on the mesa cards use a 16 bit bus, thought I'd mention this as you mentioned MII. From what I understand MII is supposed to be a more or less generic communication interface.

But I can get confused with these things .

Oh, you're right, I always assumed they were MII chips, like on all other FPGA boards.

ww1.microchip.com/downloads/aemDocuments...face-DS00002357B.pdf

Hmmm, that could make things a lot easier, since the difficult part is already in the chip.

Thank you very much!!!