All in One project

Hey everyone I've been building and making CNC stuff for the last 20 years. And have come full circle from hobby to business back to hobby. I own a manufacturing shop in Phx and lived and worked in Hongkong/China for the past 10 years so I have access to some real great manufacturing sources. Ive designed and made a very special machine that will be going into small production. Im at the stage of control currently using a DDCSV 3.1, I've used Mach3, Acorn, and Grblhal 32bit with a teensy @600hz. One of my first real CNC machines was a Tormach 1100S3 with path pilot, it is still my preferred controller even over my Haas. The Market is filling up with “offline controllers” such as the DDCSV, SMC5-5. Etc ive even made a few reviews on my youtube channel (CNCninja). After running, configuring, testing almost every controller out there like Linuxcnc the best for interaction and motion planning. But Linux and HAL configuration puts a lot of people off. So to the point, Im wanting to build a Small enclosed all in one with 10.1 touch screen Linuxcnc controller. If your not familiar with the DDCSV or SMC5-5 please have a google, Imagine this but running Linuxcnc. So the Idea would be a carrier main board similar to an SKR or Ramps but uses a plug-in RPi 4 Compute module. This is where I need recommendations. The RPi CM would interact over SPI to a step gen that will be on the carrier mainboard. The options so far is an LPC1768 using Remora firmware, an ESP32 Using Deotti-cl Firmware but direct SPI not using the ethernet, The TeensyHal32, and last the Mesa 7i90HD over SPI this option would not be a onboard solution but a plug in carrier.

The mainboard would have standard breakouts for the CM 4 but using a 10 inch touch screen and MPG wheel, there would be outputs for 4 Axis and I/O the board would naturally include opto and power reg.

So what step gen would be best to integrate into a CM4 mainboard.. My goal it to make this available for 300usd or less to compete with the DDCSV and SMC5-5. For the hobby community.

I asked around about using the rpi4 for linuxcnc a few months ago and the feedback I got was that it's not really ideal for production use. Is the compute module ready for prime time?

btw I vote for mesa for no good reason other than I've become a mesa fan.

Output for 4 axis you say, I'd say bump it up to 5 stepper outputs.

Why not go all out and put the fpga and associated circuitry with the compute module on one board.

I'd be interested to be involved. Remora was born out of wanting to utilise the RPi as a LinuxCNC platform back in 2017. It's now relatively mature and very easy to add features.

All features are compiled in and activated and configured by a human readable Json configuration file.

There is an upper limit to software generated step pulses, but how fast is truly practicle.

I've played with the TMC drivers in velocity mode. It's a neat feature but does not "close the loop" like the software stepgen and needs additional means of feedback to the control loop.

Remora currently supports up to 8 stepgens (Direct Digital Synthesis) along with software encoders, hardware QEI interface for high speed counting, IO, PWM, RC Servos, thermistors and TMC drivers via UART. SPI TMC driver module under development.

Also currently looking at how to support ethernet but this would not be needed for an all in one.

The SKRv1.4 would be a good start for the schematic. It does not have opto isolation on the IO but has everything else.

The CM4 carrier board can also be used as a basis as well. Design files are available. datasheets.raspberrypi.org/cm4io/CM4IO-KiCAD.zip