This PIC16F690 based panel lets you control a RaspberryPi with a serial communication protocol like I2C, but uses

a bitbang technique, the panel is the master and the raspbarry is the slave. The system has 2 rotary encoders

and 4 buttons, it takes power from the Raspberry.

This version has a better filter on the encoders, led backlit on knobs and buttons, below some photos with different colors.

For plastic overlay/mounting panels + video click here.

sPANEL source+binary

raspberry twowire source+binary

spanel 01 board

spanel 01 sch

 MG 3088

 MG 3099

 MG 3085

 MG 3057