The Simplest Thing

This is really very simple, and in fact, I've been using such servo drivers for various projects for quite a while, for instance in #µKubik quadruped robot. But now I want to actually design a proper PCB and write proper, universal, code. The PCB would go on the back of the Pro Mini, saving a lot of space. It would be something like this:

It's mostly servo sockets, with a room for an optional capacitor, a power plug, and a jumper for connecting the Arduino's power with the servo power, if you want to power them from the same source. The I²C pins are not included, because they would need to be accessed from the other side, otherwise I would have to have 3 servo sockets fewer.

As for the code, so far I've used very simple approach, using the Arduino's "Servo" library, which can handle up to 12 servos. If I manage to use a custom library instead, I can use all the pins -- up to 18 servos (assuming I²C control, because the serial pins would be used by servos too). There would need to be some configuration in the code -- whether to use the serial pins for servos, and the I²C address to use, etc.