Schematics have been basically finalised, although check the GitHub one for the most up to date version. I have been using KiCAD for this project, having moved from designing in Altium for another project over the summer. Really impressed with the functionality and keyboard shortcuts of KiCAD, everything is just what you expect it to be.

Most of the circuits are based off each devices application circuit, along with comparisons to the breakout boards I have for many of them. If you have any feedback or questions, pleasedon't hesitate to comment!

MCU

Power Management

Audio

GPS and IMU