I really like the idea of Web Ground Control and I absolutely think something like that is the future. I would like to start designing a controller specifically to work with Web Ground Control.
CNCs using stepper motors are VERY sensitive to timing because the motors require precise and high frequency pulses to move. A closed loop system like ours should be a lot more forgiving about timing (especially if the processor is much faster than the motors) so I think we may be able to get rid of the Arduino entirely and control the motors directly from something like a Raspberry Pi. It’s still a theory, but I’m interested in playing around with it more.
My first thought is to use the Raspberry Pi Zero W which gives us a good amount of processing power, SPI, and wifi/bluetooth in a small package. The SD card is a pro and a con. I like that it easy to replace the software completely with a new SD card, but also it adds cost and I am a little bit worried about dust getting in there. The need to solder on headers is also not ideal, but workable.
Something like the Raspberry Pi compute is built for that type of thing, but it doesn’t include WiFi and is not easy to reprogram for the end user (and being hackable is important).
Does anyone have any other suggestions for little cheap wifi boards which could run a little web server and some PID loops?
Edit: On the other end of the spectrum something like the Air602 for $1.90 is designed to be soldered directly to a PCB. The cons are that it doesn’t have the huge support community that the Pi does, and with 1Mb of storage we aren’t going to be having any fancy pictures in there.