Ergodox

An opensource DIY keyboard originally developed by dox, featuring a split, ergonomic layout and QMK support. 80 (or so) keys, USB, customisable like few keebs. I bought a kit and starting building with Mina at Domain, but it has languished in a drawer since then.

Nyquist

The name Nyquist comes from the Nyquist sampling theorem, which says that if you want to sample a signal to convert it from analog to digital and be able to uniquely reconstruct the signal later, then the sample rate has to be twice the bandwidth of the signal. So here, if you want to sample this PCB, you're going to need 2 of them.