LinuxCNC + Orange Pi (allwincnc)

Hi, guys. Let me introduce a tiny project of mine..

My first single board PC was the Orange Pi One. And it's really fun to use such boards for a hobby projects But we also can use them as a small CNC controllers too. It's really sad there are no armhf packages in the LinuCNC dists repo. So my first try was the Machinekit with RT-PREEMPT kernel built using Armbian. And it works. But without a GPIO driver it was just a simulator. After a few weeks of learning I made a GPIO driver by myself. And it works just fine

My next step of researching was a "big latency" issue (50-70 us). Many ARM boards has a worst latency values using the RT-PREEMPT kernel. A steps rate with such latency values was terrible. A few months later I found an info about additional built-in RISC CPU core. Using this core for the fast pins toggling was a good idea

At this moment I have a working pair of HAL driver and the RISC core firmware. Steps rate now very high (up to 1 MHz). Also I made a quick installer script. You need one of the Armbian images to install it. Supported boards are Nano/Banana/Orange Pi with Allwinner H3 SoCs installed.

Attention! Project support is ended. Use it on your own risc.

allwincnc.github.io

Amazing. I have to test this.

What do you think of making an encoder module that runs in the RISC cpu?
How fast can it sample in-signals, would you say?

Hakan wrote:

What do you think of making an encoder module that runs in the RISC cpu?
How fast can it sample in-signals, would you say?

A RISC core can sample the AB sequences pretty fast. Max input frequency can be up to 200-400 kHz. But I haven't any high res encoders to test it. So these rates are theoretical maximum (based on output rates).

Very nice. We had some Allwinner devices running LinuxCNC back in '13-'14. Back then the mali GPU was still closed and there was no info on the integrated microcontroller.

Machinekit could have used these and come up with a working system as well. Nice to see that you have the ARISC core going now for software stepping.

This system can be more open source than the Rpi4 since it requires no giant video blob.

Thanks for your effort on this project. I really like it!
Looks very promising to me. Documentation looks also great.
In my opinion it would suit the gap between Laptop+GRBL and full sized LCNC(+MESA) quite well.

Just ordered an orangepi zero plus 2 H3 (due to emmc and no need for a lot of IOs).
Hope the 512Mb Ram is enough.

I am looking forward to test this on my mills and mini-lathe.

Besides closed loop, an encoder module would allow for threading on the lathe/mill as well as rigid tapping.
PWMgen would also be useful to people who use some of these 0-10V controllable spindles from Kress/AMB or Mafell (mostly Europe).

Sadly i am not a experienced programmer, but i will dig into your code and try to understand how it works.
I will also try to keep up on your thread on cnc-club.ru via google translate...

Keep up the good work!

It seems like the LinuxCNC encoder component would be a good starting
point for encoder support in the attached processor.

arisc_pwmgen/arisc_encoder will be added soon..

I've bean looking for a compact setup to use on a small CNC mill.
This looks perfect.
I'm about to order a Orange Pi Plus 2E and some TMC5160TA drivers, that should cover most of my needs.

Edit: I'm not any good with Russian, but I've bean reading through your other thread, it looks like you're working on an Orange H6 board.
But aren't seeing any performance gains.

Right now the H3 board is the best supported, but I wonder which will be better in a month.