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

works
 

5Axis
8 Inputs (OPTO)
8 Outputs (ULN2803)
3 PMOD Expansion-Ports
 

Cool

I tested stepgen.
next step try check encoder.

Love your work!
Where and when can we get to buy the boards?

thanks stefan,
where are you come from ?

the problem is, i am from germany and I don't know if it's worth it to send finished boards to the USA or anywhere else.

greeting olli

I see in your video of the TangNano9K it's connected to a DB25 which is then connected to some other board(breakout) which then drives some stepper driver boards. My question is, will the TangNano9K, with RIO, directly drive a CNC having "standard"/Mach 3 type DB25 connectors and opto-isolated control/drivers internally? I have a Chinese CNC3040T in this configuration and would be willing to try RIO with it. Thanks.

Also wondering what that Ethernet to SPI board is on the other side of the Tang Nano 9k?

PS, I did some work with Scott and Remora and found that by using a standard ribbon cable for 3D printer remote displays and grounding every other wire in the ribbon, I could get SPI to work reliably out to almost 300mm.  My PCB adapters( dirtypcbs.com/store/user/edit/6524 ) but for the rPi side I designed it for the Argon One Pi 4 case( www.aliexpress.us/item/2255800056869749.html ).

From my notes, the Mach3 DB25 controller pinouts look like this and were determined from some Arduino code and a video of connecting to a Mach3 controller:

From Video CNC LPT Pinout
db25 Pin Description
1   A Enable
2   X Step
3   X Direction
4   Y Step
5   Y Direction
6   Z Step
7   Z Direction
8   A Step **
9   A Direction **
10  Reset / Abort / E-Stop
11  Z limit( Mach 3 video =X)
12  Y limit( Mach 3 video =Y)
13  X limit( Mach 3 video =Z)
14  X Enable
15  Probe
16  Y Enable( Mach 3 video =Output1)
17  Z Enable
18 - 25 Ground
 

the tangnano9k is directly connected to the bob, you can simply solder an adapter to the DB25 Connector.

BUT !!! the FPGA is not realy 5V tolerant, pullups are ok, i have no problem with my china BOB, but i can't say if it works with other BOB's

The Ethernet-Board is an optional UDP to SPI bridge, so you can use any PC.

And before you are frustrated, please try to build the project before buying the hardware, some user have problems to compile the firmware.

EDIT: you can map each pin to more or less each function
 

the 8Inputs + 8Outputs Board's also works now
the boards are stackable !

 

ok, I was hoping the Tang Nano 9k might be as compact as I'd done with an Arduino Pro Mini(5v) and a DB25 breakout connector. I had an esp32 working for a little bit but the driver chips I used must have been on the edge of working for driving the opto-isolators on the CNC driver board ahead of the TB6600 drivers as it got intermittent after a few tests.  I was hoping to not put such a big box behind the CNC although a meter long RS232 cable might still work.  This is the same reason why I've not jumped on Remora on the CNC. I've had rPi/LinuxCNC/Remora working on a K40 laser cutter and an Ender 3 3D printer so your FPGA setup has my interest.

I run only Linux software but I will try to create a build environment and build your firmware and see how it goes. Without configuration files building the firmware sounds like the way to make it work on each machine.

Thanks for explaining that Ethernet/UDP/SPi board.  Sounds like I using either rPi and TangNano9K directly over SPI(~300mm length) or the Ethernet option with either rPi or desktop/laptop. Nice.

I'll start looking around for a BOB. Should be some that'll work with the ESP32 and RIO interchangeably and hopefully with enough drive for the opto-isolators.

 

How about LPT-port to connect tang via SPI protocol ?