Here are a couple pictures of R2, the latest, greatest version. Compare it to R1 on the right.
The largest glaring difference, as I hinted at in the last log, is that I put a PIC microcontroller on there.
It has an open source USB stack, plenty of I/O, is mature, and I know how to use them very well.
The idea was to use it as the main processor, just handling simple wifi transactions with the ESP8266. Stretch goals would have the PIC programming the ESP8266, and maybe vice versa, too.
That single-handedly eliminates the CH340G USB-UART chip, the serial-parallel shift register for driving the parallel LCD, and the WDT/poor documentation headaches of the ESP8266.
After initial bringup, it's just been sitting on my bench, however. Staring at me. Since then, I've been collecting little snippets of Digikey part numbers, ideas, and technologies that will be incorporated into R3.
But for now, I think I will finish getting this up and going as desired. I previously wrote a quick LCD driver for a PIC dev board I have, so I'll transfer it over here, solder the LCD ribbon on, and write some image serialisation code between the two micros.
Perhaps R3 will use the ESP32? It solves a few of the problems neatly, and soon ESP-Mesh will be released.