Regarding licensing, sorry about the confusion between my repo init and the docs. I have updated the repo to clarify the distinction: Firmware & Software: MIT License. I want people to build whatever they want on top of the stack. Hardware Schematics: CC-BY-NC-SA (Non-Commercial). Why the split? Since I am a solo bootstrapper, I need to protect the hardware from low-effort commercial clones while I get the business off the ground. But I strongly believe in "Source Available" schematics so researchers and engineers can debug, learn, and modify their own units, hence the CC-BY-NC-SA choice for the board files.
Why start fresh? It was an architecture decision. The Cyton uses a PIC32 + RFduino stack. I wanted to handle everything natively on the ESP32 for high-bandwidth WiFi streaming, which required a ground-up redesign. I also wanted to add onboard LiPo charging and the ability to experiment with different filter topologies. Building it from scratch helped me uncover a lot of subtle design constraints that aren't obvious until you dig into the layout.