Peter Cock designed a Bluetooth and diode-free replacement PCB for the Gamma Omega. The Gamma Omega Hesse is using graph theory, resulting in 4KRO.
This iteration of the Gamma Omega family of 36-key keyboards is the first wireless one which supports Bluetooth, specifically BLE using ZMK firmware. This meant a change in the controller […] this design uses a Nice!Nano v2 […] 21 GPIO pins. The compromise means using a bipartite girth 6 graph of 21 vertices and 36 edges, giving only 4-key roll over. This is the Hesse Configuration Incidence Graph, also known as the incidence graph of the affine plane of order 3 – Peter.
Read Peter's blog post about the design process, including choosing a controller and picking a graph.
