here another project. it's a box for replacing some old midi hardware. it can read 16 analog sensors, 16 digital sensors and control 16 leds via pwm. basically it is just a teensy plus a pwm breakout board from sparkfun. to easily access all the pins on the teensy, i also used the excellent Teensy 3.2 Breakout Board R3 by Daniel Gilbert.
attached are schematics, teensy code, and supercollider and maxmsp code for dealing with the serial communication.
update 161011: fixed a silly but severe error in the max patch