This project contains all design files for a 6:1 audio multiplexer , meaning it can switch six analog inputs into one analog output.

It is based on the BD3491 which does everthing related to the Audio signals.

On top of switching the inputs, it is also able to condition the signal. It can

• Apply Bass-Boosting and Treble-Boosting (essentially a crappy 3-Point Equalizer)
• Amplify the input signal by up to 20dB
• Add attenuation to the individual channels (aka. balance the left and right channel)

All of these feature of the chip can be activated with the on-board STM32, which can in turn be controlled with either on-board buttons or via it's integrated USB port. One can either use the serial protocol directly or a GUI written in python

The Board can be supplied over said USB port as well (if the primary use-case implies it beeing connected to the PC constantly) or by applying power using a 2.1mm Barrel Jack.

For more details on the pcb, check the PCB readme

For details on the Serial command syntax and firmware flashing instructions, check the firmware readme

Why

Because ?

Sometimes you just need more inputs. This is how you do it.