@joedevivo I've been trying to load QMK on my Dactyl but it just hangs during i2c_stop. It sounds like it just worked right out of the box for you, yeah? I've been pulling my hair out about it, but if it worked fine for you then maybe I just need to redo my i2c connections...

@ErinCall did you ever get this working? Sorry for the long delay on my side

I did. I'd accidentally used 220kOhm resistors for the TWI wires instead of 2.2kOhm. Now I don't understand why ergodox-firmware ever worked!

The I2c is for the expander to communicate with the teensy. Like it says in the guide you can wire and test the right side without the left! :) On the right side, I was able to wire up 2 rows + 2 columns and able to test keys in the 2x2 squares covered by the rows and columns I connected, so nothing connected to the teensy except 4 wires! Thanks for this guide.

@joedevivo Do you use firmware for ergodox ez or handwired/dactyl with this wiring? It could be worth mentioning in the guide.