'Kitchensink-ish' TOH with all components remotely related to audio.

You name it, it will be there:
- i2c level converter
- i2c spi bridge
- micro-sd card
- full sized sd card
- sd mp3 decoder
- digital volume controller
- separate amps for L & R
- FM receiver
- headphone jack / line in
- micro usb port

Still to add:
- FM transmitter
- bigass speakers
- battery
- charging circuits (in/out phone & separately)
- physical control buttons
- full sized usb slot
- usb host (just for reading mp3s)
- lightning connector


This one will be the most complex TOH ever. I have my doubts it will ever see the light or be remotely affordable. But I learn a lot.

The basics:


SD slot and MP3 decoder:


FM receiver:


Amps and volume control: