The actual schematics for this project are super simple. Three breakout boards and a Teensy 3.2 were used. 

Originally a lower power microcontroller was used, as nothing in this project really requires the Cortex M4 or advanced feature set of the Teensy 3.2. However the project was transitioned over to this development board in the hope of one day creating a great sounding synthesizer on the same chip. 

Breakouts for the MPR121 and BNO055 were used because I had them handy, but when the kit is developed I plan on having them native to the PCB. While MPR121s are at end of life, they are still readily available, and if become hard to source it would be easy to switch to another capacitive touch IC.

This schematic does not show the wireless serial connection, but for those who have an amateur radio license in the US, they can utilize the APC220 which is a really superb option for this project.

My prototype also has two pull-down resistors on SDA and SDL, but were not needed when using the breakouts from adafruit, but add them in if you are having trouble with your I2C.