Hi guys! I have 104-key WASD keyboard about more 3 years. And last years I can’t leave thoughts about making it Bluetooth wireless.
At beginning, I had try to make usb-2-bt converter like
https://github.com/juancgarcia/HID-Relay. It worked success except that my WASD-keyboard don’t turn on leds when it was connected to usb-host. I checked my hid-relay with other USB-keyboards, they worked properly, and their leds worked. However, not with my WASD.
Then I had decide to make own custom controller. I have made reverse engineering of board wiring. Keys board has two header-connector for controller board.
Totally, this keyboard has 8 rows and 18 columns. I decide to union Win_R & Win_L single columns with other. It reduce columns to 16. In addition, board has 6-key DIP-switch to configure (layouts, mode…) and 3 led.
Total 8+16+6+3=33 I/O ports. It is too much for typical Arduino/teensy boards. It can be reduce by using bi-directional multiplexor. 8 rows can be reduced by 74HC4051 to 3-bit line. 16 columns – to 4-bit line by 74HC4067.
So 3+4+6+3=16 I/O ports – it is enough to choose any arduino/teensy compatible board.
It need to say that also RX/TX lines required for communicate with rn-42(hc-05). Wireless mode can be turned on/off by one of DIP-switch or just additional switcher on keyboard’s cover.
Now I can’t choose and ask for help of community - which one of teensy-compatible board to select?