I had a bit of a break with this project, while I worked on other projects and dealt with some life stuff, but I very much still want to work on it. Obviously the very next step that needs to be done is to program the robot to do actual walking, at least at the level of #Tote, and then possibly make use of the accelerometer and the leg switches. I assume that this will actually take me some time. In the mean time, CircuitPython is being developed further and ported to the NRF52 chip, growing bluetooth support along the way, so the long-term plan is to switch to NRF52 from the SAMD21 chip. That will probably involve a redesign of the extension connector as well, so I don't think I will be working on any extensions until that happens.
Once the connector design is finalized, it will be time to look at possible extensions and the sensors to include on them. I want to have an OpenMV adapter, and also a simple "face" with distance sensors on it.