20-channel Servo Shield

Yes, I keep refining the design. No, I don't actually need all those servo shields. But it's a fun challenge. So I made another one, this time controlling up to 20 servos at once.

Note how all the servo sockets are on the edges. That means that if you use angled 3×10 male headers, you can actually stack those. And with the address selection on the analog pins, you can have up to 4 shields at once. That's 80 servos. Of course, if you just reprogram them to use a different address, you could have hundreds of them.

So where are the two extra servo channels coming from? Turns out that if your ATmega328p uses an internal oscilator and you don't have an external oscilator connected, you can use those pins as gpios.

I'm still conflicted about whether to actually order this board or not. One idea is to order it, rewrite the firmware in plain C, and submit this to the 1kB contest...