The encoder boards (ATmega328P, Atmega2560, Apple2(2560) can accomodate
keyboard matrices with no diodes, by adding per-row diodes on the
encoder board. For keyboards with per-key diodes (the typical use
case), the per-row diodes are not needed, and therefore the footprints
should be shunted by default, using a special shunted diode footprint.
When diodes are installed, the shunt can be cut with an x-acto knife.
Previous board revs had the correct footprint, but somehow the regular
diode footprint was substituted on the last release of each of these
PCBS. The correct footprint has been restored.
- Moved header slightly forward
- Moved interface mount holes do reduce interference with case mount holes
- For all keys in classic keyboard, add option for either through-hole or SMT
diodes and resistors.
- Clean up diode positioning and numbering
- Remove 3D models for devices that are not normally fitted
- clean up labeling
- update README files to match PCBs.
For better matching of current limit resistors to LEDs, the resistors are moved
to the keyboard matrix PCB, where they can be tuned for maximum brightness (at
100% duty cycle). This allows consistent keyboard brightness when a single
interface PCB is swapped between keyboard matrices.
- swap numbering of row select protection diodes for cleaner PCB labeling
- clarify labeling on GPIO pins on the MCU
- bump rev to 2.4 to indicate work in progress. Release will be 2.5.
- Add extra key to the left side of row 4 to permit "inverted T" for those who
want it.
- Tiny shifts of several keys to correct key distances
- Include mounting holes with daughter board connector, to ensure consistency.
- Fix wrong direction DIP switch diodes
- Add buffers to permit ISP lines to also be used as output and LED drivers
- Allow 3 keyboard LEDs and 3 host outputs (RESET, CLEAR, BREAK, LOCAL, etc.).
- Outputs 1 and 3 are general purpose (can be open drain or driven). Output 2
is open collector (with optional on-board pullup).
- Add apple 2 mounting slots (and stretch PCB to accommodate slots
- Add pass-through holes in aligners for OSI keyboard spacers
- Move 'ESC' key next to '1' key
- Add TAB key next to Q key
- remove 'here is' and finalize "helper" keys along left side of keyboard
- move legends off of PCB traces
- update to release 1.3
- Add OSI-compatible mounting holes.
- Adjust keyboard and aligner holes to make room for the OSI mounting holes
- Change "Universal Keyboard" to "Unified Keyboard" in the design files.
