The Controller Board

My prototype is made on perfboards bought here. I don't really recommend using these, they're of very low quality and I had several issues with them.

This board includes :
- the ATMega chip wired in standalone mode
- a CD4021 chip for footswitch input
- a voltage regulator

The eight momentary footswitches are directly linked to a CD4021 chip, that will read the current input and transmit it to the ATMega with a serial signal.

The footswitches could be directly connected the the ATMega I/O pins, but I wanted to reduce the number of pins needed, thus the CD4021 chip.

Here's a great tutorial about this.

The 7805 5V regulator is wired this way :

Once everything soldered, the controller board looks like this :