Yikes. Yes, those were swapped. Fixed. Thank you!
I do have a few specific questions that I'm still confused about:
1. I am especially uncertain if the resistors are set up correctly connected to the IO Expander on the left half.
2. Are the diodes in the right direction, considering that the board is split?
3. On the Ergodox, I see that most builds recommend that a capacitor is added to the left side at the IO Expander. What pins would I connect that to in this build?
Hi, Tye
1: I2C lines should be pulled-up to VCC. It looks ok for me.
2: Direction of diodes in the key matrix depends on MCU firmware. In your case, you have to read COL value while chaing ROW level. Some people connects diodes to ROW wise if they choose hand wiring. It is easier to connect output line horizontally while most keyboard have straight row of keys.
3: Decoupling/bypass capacitor should be placed near each VCC pins of ICs. If they has coupled GND pins with VCC pins, place a capacitor near both pins. In genral, 100nF (0.1uF) capacitor is used for such case. It reduces noise on power line or helps to make power line stable. You have dozen of LEDs on the board, so if you tern on many at the same time, the power source would be unstable.
- You have 1000uF capacitor on VBUS (5V) line but USB specification recommend capacitance up to 10uF on VBUS line for bus powred devices. They saids if capacitance is quite large, pins on USB connector would be melt by rush current when you connect plug.
- You should decide screw positions to fix the PCB in your case or something before moving some components around on the board.
- You can prepare additional pattern for spare capacitor on left side which can be soldered if your circuit is not stable enough.
- I have never used SK6812. Its datasheet recommend bypass capacitor on each SK6812 on typical circuit.