I'm not too familiar, but I've been told shift registers or IO expanders can save pins. In my small amount of research, it seems like they work (both of them seem to do the same thing? I'm honestly not sure what the difference is) by converting parallel signals to serial signals like SPI or I2C. For example, with I2C (the one that requires fewer wires), I think you could wire up your 4 columns... to the 4 wires of the I2C standard, which are VCC, ground, and two data lines, but if you're able to use those same lines for ground and VCC for the rest of your board too, you'd be effectively saving two wires. Note1: If they share VCC cable with the RGB's you'd have no ability to cut the external power, but maybe for a wired board you don't care about that. Note2: Not sure if you could wire all 7 matrix wires to one expander... for me at least that wasn't an option because to not have to do constant polling, you can only use an expander on the output side of the matrix. Avoiding constant polling is a power concern when building a wireless board.
ErgoMechKeyboards
Ergonomic, split and other weird keyboards
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Posts must be of/about keyboards that have a clear delineation between the left and right halves of the keyboard, column stagger, or both. This includes one-handed (one half doesn't exist, what clearer delineation is that!?)
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Some useful links
- EMK wiki
- Split keyboard compare tool
- Compare keycap profiles Looking for another set of keycaps - check this site to compare the different keycap profiles https://www.keycaps.info/
- Keymap database A database with all kinds of keymap layouts - some of them fits ergo keyboards - get inspired https://keymapdb.com/
I'd drop the RGB man.
Or with diodes, could you logically arrange your 24 keys into 4 rows / 6 columns (or even 5x5) and save any pins that way?
Edit: you're already doing a 4x3 per side. Nvm
HDMI cables, with 19pins (I will use it in my next build), or flat cables, which you can find in different sizes and pin counts (I used some with 10 pins in my Rommana). Both types of connector and cables can be easily found in Aliexpress.
Thank you. It was specifically the CAT6 I was Looking to use, as you can get an ultra thin patch cable, and it will clip in (so reduced risk of shorting the controller). Maybe I need to go without RGB? 😭
There are keyboard matrices that can accommodate more keys with fewer pins. E.g. https://kbd.news/Square-or-round-robin-matrix-1400.html. This one can do 12 keys with 4 pins. But needs some careful component choices to avoid ghosting.
Oh, that’s awesome. Thank you!
I’ve taken a look, and it seems that this might be exactly what I was looking for. Frees three cables up for the RGB.