Right now I'm just looking further ahead at the Tetent implementation to see if there's anything else that would be required to connect to a Tetrinsic that can't go though I2C.

• Essentially, the part that'll likely be called Tetent PCB is a PCB that has 
  • 2 USB Type-C ports, 
  • maybe the DAC if there isn't enough space to use the off-the-shelf stuff,
  • the USB PD chip that negotiates (ideally) 12V,
    • This is because both the BLDC, BLDC controller and any potential mini PC I use in #Leti use 12V. I wouldn't be suprised if the DAC and speaker also worked on 12V. 
  • and the circuit that deals with charging the batteries.
    • I could probably get that one seller to put together a 2-cell for Tetent, but I'm also looking ahead at #Leti and how I'd (ideally) want 8x 5Ah cells. That's 148Wh, and airlines accept up to 160Wh in carry-on, though I've only seen references for power banks / spare batteries. I certainly don't fly often enough to worry about it right now though.

So far, I've found

• Power Delivery Board from Sparkfun
• LiPow