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

new 6axis DC-Motor Controller
youtube.com/shorts/BiJppd6_cA4

Question, does it normally take 2 hours to flash tangbob board?
Using the example config file.

Thank you

no is not normal, should only take a few seconds, try a different cable

Hey Ollie, with Riocore I've got 4 axis closed loop to the controller going on my mill, well only one axis for now but I've tested the other 3 will work, so thanks heaps for that !

The only issue is that if you use line reciever ic's (26LS32) and RJ45 sockets it all takes up a lot of PCB real estate. I'm thinking of utilizing an off board encoder solution. The LS7366 chip looks like a good candidate, its a 32 bit quadrature counter that will decode at 20 MHz at 3 volts. (40MHz at 5V)

This chip uses SPI, which I honestly know nothing about, my question is if I was to make a seperate 8 axis encoder board to cover all the axis's MPG, spindle etc, would that work with your existing SPI plugin ? And I'm not sure if the LS7366 will daisy chain or if there needs to be an additional IO pin per device, in which case it may not be worth the overhead.

Cheers.
Russell.

Hi Russell,
the LS7366 are no longer manufactured and you would have to write a new plugin. The ones you can still get are also quite expensive.

can't you just make a plug-in board (on the top) and route all the encoder pins to the top via pin headers?

Cheers, Olli

Hmm so I had checked the datasheet earlier, never actually looked at price and availability, I see what you mean.

The main idea was to save pins, they run out quickly on the tang nano. I guess the simplest solution is to step up to the spartan 6.
There is OctoQuad by DigitalChickenLabs for the pi pico that will do a similar thing for 8 encoders via I2C but as you say it would also require a new plugin.

Cheers.
Russell.

I prefer the ice40 when I need more pins, e.g. the Devantech iceWerx iCE40-HX8K.
it has the advantage that it can be used with the opensource toolchain.

otherwise the tomverbeure.github.io/2021/01/22/The-Col...velopment-board.html is also pretty cool

That ECP5/i5 board is VERY cool.

On your Git page you mention the network interfaces are not supported, do you mean we can't use a Wiznet module or are you referring to the 30pin ethernet connector on the dev board ?

Having over 100 IO pins available is definitely the dream, is programming as easy as the tang nano? Will it program via the USB-C connector within Riocore like the Tang?

Would there be any advantage in getting the i9 module over the i5 for our purposes ? It works out more expensive but not too much.

Cheers.
Russell.
 

only the onboard mii chips do not run, the w5500 runs with all boards and toolchains.

the programmer on the additional board is very slow, better use a USB blaster to access the JTAG pins, it works great with openFPGAloader

I would prefer the i5, it has the ECP5 on it and is best supported. It's also so big that you won't get it full

Cheers,
Olli

OK cool, thanks for that, I think I'll try it out. The tangnano is doing the job nicely so far but runs out of pins quickly when you include 4 axis closed loop with index pulses.

Cheers.
Russell.