1 and 0 are the only keys a true programmer needs
Now with Unicode support!
In a fit of inspiration, I threw this together in an evening. It is a small keyboard with three keys: 0, 1, and enter/submit.
Unicode support happened a separate day.
The 0 key types a "0". The 1 key types a "1". The enter/submit key types the enter key.
This is the true binary mode. To type an ASCII letter, press a combination of 8 0s and 1s (MSB first) then press enter/submit. If you press enter/submit with greater or fewer than 8 bits, this clears all of the bits. This allows you to clear screwups without having any letters actually typed.
As a modification to "Mode 1", you can now enter Unicode characters!!! Instead of just typing 8 bits, type anywhere from 3 to 8 nibbles before pressing enter/submit. Typing exactly 8 bits will fallback to the standard Mode 1.
For Linux, the keyboard uses a modification of the CTRL+SHIFT+U method. It has been tested with Debian Jessie (Xfce) and partially tested with Ubuntu 14.04 (Unity).
For Windows, the keyboard uses the ALT+NUMPAD_PLUS hexadecimal method. This requires a registry edit. To HKEY_CURRENT_USER\Control Panel\Input Method add a string (REG_SZ) called EnableHexNumpad with the value 1 then reboot. Unfortunately, Windows doesn't seem to like anything more than 4 nibbles with this method. There are other methods, but this is the most universal for Windows. I'm very open to suggestions for ways to fix this.
When plugging in the USB cable, the keyboard will startup and default to Mode 0, QWERTY, Linux.
- To switch to Mode 1, hold the
0key when plugging in the keyboard. - To switch to Dvorak, hold
1when plugging in the keyboard. - To switch to Windows Unicode mode, hold the
enter/submitkey when plugging in the keyboard.
Key(s) must be held for around 7 seconds (dependent mostly on AUTO_EXIT_MS defined in the Micronucleus bootloader).
The body of the keyboard is 3D printed. Mine was done with a Monoprice Select Mini, but it's a small and forgiving design, so just about any printer should work.
The 4 keyswitches should be Cherry MX style. I'm using Gateron Blues. The 2u keycap needs double stems. This could be changed to fit a single stem or triple stem with stabilizers 2u keycap if the OpenSCAD files are changed.
The controller is a "tinyDev" board of my creation. Order it from PCBS.io or from OSH Park or elsewhere. Both PCBS.io and OSH Park are super cheap for small boards.
The keyswitches share a common ground on one pin. The other pin connects directly to pins on the tinyDev. 0 to B1, 1 to B2, and enter/submit to B0. This can be easily changed in the code.
Place the keyswitches in the top panel, solder the switches to the tinyDev, place the tinyDev into the base (add a little hot glue to keep it in place), and fit the top panel to the base (should be a snug press fit, if not, use glue).
The attiny85 on the tinyDev comes blank from the factory, so an ICSP such as the USB-ASP is needed to initially program it with the bootloader. A SOIC test clip helps immensely. The bootloader can be found here. You may need/want to use the one that ships with the Digispark Arduino installation.
Install the Digispark boardstuffs to Arduino.
Resistors and capacitors are generic 0805
2x 68ohm
1x 1.5kohm
1x 100nF
The two diodes are 3.6V zeners in a SOD-323F package. I used MM3Z3V6CCT-ND
The attiny is ATTINY85-20SURCT-ND
USB connector is Amphenol 10118194-0001LF (609-4618-1-ND on Digikey)