The first step in creating my Raspberry Pi based Linux palmtop computer is to have a functioning USB Keyboard (which can be used separate or integrated with the palmtop directly. This is the part of the project that has the most unknowns to me so I'm tackling it first.
I already have a USB Keyboard PCB design based on the Blackberry Q10 keyboard, the teeny tiny "BM14B(0.8)-24DS-0.4V(53)" connector and an ATMEGA32A-PU (which will run the QMK Firmware). There is some excellent documentation on this Github project that I'm working off of. I would love to just have some of the boards manufactured and get on with the palmtop design, however there are still some unknowns (to me).
- How do I control the backlight LEDs? There are 4 pins on the connector for the LEDs but I haven't been able to find any information on how to control them.
- How can I use the MEMS Microphone that's built in to the keyboard? This isn't a must but it would be incredibly useful to be able to use that built in microphone.
- Does the keyboard have built in diodes to prevent key ghosting, or will I have to include those in my design?
- Are there any other Gotchas in interfacing the keyboard that I should know before finalizing the keyboard design?
So as a first exploratory step I've designed a breadboard friendly breakout board for the keyboard. (I got the idea from this project) I'm getting the boards produced by JLCPCB and if they work I plan to sell them if anyone is interested - I'm kind of hoping this will help me finance the next steps of the project although that may just be a pipe dream.
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