Universal Servo Breakout

The first attempt at this was made when I was only using small Arduino clones, some Teensies and Trinkets, and an odd STM32 board. All of those boards had the same width, so my first attempt only had two rows of female headers:

(The holes are there only to make it look cooler.) The connections are pretty much what you would expect from a servo breakout:

The dimensions are 5×5cm, the largest I could get made for cheap.

The second version was actually made on a strip-board, and had some modifications to allow a variety of different boards, such as:

Arduino clones:

Teensy:

Teensy LC:

Maple Leaf clone:

"Blue Pill" STM32 board:

Another odd STM32:

WiPy:

Espruino Pico:

and a bunch of others. I also added a power switch, so that it's easier to make changes in connections safely.

So, after getting Mark II to its current state, I decided it would be nice to actually have a bunch of ready boards like that, with a switch and maybe a capacitor. I sat down and designed the newest version:

Depending on which holes you populate with male/female headers, it should be able to accept a variety of boards -- all the boards supported by Mark II, and also an ESP8266-1, PyBoard, ESP8266-12 on a breakout, etc. It won't work with Raspberry Pi or Arduino UNO -- that's impossible for this size.

This is the PCB I ordered before I made all the improvements of Mark IV. To be honest, I think it's mostly good enough, and I will end up using this and not ordering Mark IV.