TinyRC: Tiny Tiny Tiny Controller

    I'm updating my tiny remote control Zoox and a decent amount of that update is in the controller, rather than the vehicle. First and foremost, I'm replacing the old Raspberry Pi Pico and NRF24 radio with a Raspberry Pi Pico W with built-in bluetooth. And then I'm replacing the extremely overkill 820mAh battery with a tiny 100mAh battery. I'm also adding in a battery control board that allows me to recharge the battery via USB-C without opening anything. And finally I found connectors that allow me to use the ubiquitous inexpensive tiny Nintendo Switch joysticks.

    After a few iterations and plenty of mistakes, it's finally complete and working. It's one of the simplest PCBs I've made recently and it's also about a third the volume of the previous controller. At this point the size is determined by the Raspberry Pi Pico itself. I can't make it any smaller if I want to use the COTS board. But if it got any smaller I wouldn't be able to use it comfortably.

    So now I have to get the vehicle working. It also has a very simple PCB, simpler than the previous version. The code and electronics are all working, so now all I have to do is get the incredibly tiny drivetrain assembled and tuned. That might take a while still.