I've been working on a crazy project to assemble / build utilities for the Raspberry Pi to maximize the usefulness of it with the M100. I crammed a TTL-RS232 converter inside a tiny little case. Slapped a button on one of the GPIO ports to trigger an APC-Shutdown and that's pretty much it. I tried running the Pi off the M100 using BKWs incredibly awesome BCR-USB-Power adapter (https://github.com/bkw777/BCR_Breakout) - it works, but eats the batteries too quickly. So I'm using a tiny little power bank instead and it works fine. (Even have a nifty little USB to 6V power cable now that also runs the M100.)
R-Pi gives me storage, wifi and a host of other utilities but it's all through the tiny little screen. I constantly find myself breaking out my phone / tablet or laptop to do complicated stuff and it got me wanting to leverage the M100 keyboard and the full graphic capabilities of the Pi. I fired up a VNC server on the Pi, it's part of the raspi-config setup now so super easy to do, and went to work trying to figure out how to pass keypresses from the Linux CLI to the host. I figured I could use my phone or tablet as a remote display for the Pi X11 Desktop. After learning WAY more about barcode readers than expected I settled on a keyboard wedge method using X11-Test. Lashed together a quick little perl script to send the keys to the X11 server and amazingly it worked! I still need to add some inelegance for special characters but I am sending this e-mail right now, from G-Mail, using my R-Pi as the host and my M100 as the keyboard. The Pi-Zero is horribly underpowered memory wise though, so it's painfully slow. May be worth using a pi (or other device like my GPD Micro PC, wouldn't even need VNC for that since it has a screen.) with more memory.. Here is a quick video demo for anyone who is confused/curious: https://youtu.be/GIv831sT50w Brian