Can this design be modified to send midi through USB and can 6 more piezos be added?

https://www.midikits.net/midi_26drums_16velocity/midi_26drums_16velocity.htm

 

In short, no.
Unless the MCU has some spare I/O pins to handle the extra piezos a different IC would be needed.
The software inside the MCU would have to be modified or totally re-written. The MCU on the board probably has its software protected.

 

In short, no.
Unless the MCU has some spare I/O pins to handle the extra piezos a different IC would be needed.
The software inside the MCU would have to be modified or totally re-written. The MCU on the board probably has its software protected.

Thanks for responding, I built a unit that has 22 piezos and a FSR to trigger midi notes. I thought I could find a board that could do this but so far no luck, any ideas?

 

At the site: https://www.midikits.net/downloads/downloads.htm they have the source code for a 16 midi drum. Perhaps you could modify the code to suit.

 

would a raspberry work?