[ot][spam][crazy] muse-lsl bleak work

[Undiscussed Horrific Abuse, One Victim of Many]

- the schematics do not appear to label the chips
- there is a documented led called 'BT_ON' that purportedly lights
when bluetooth is powered. this string does not appear to be present
in the raspi 4 schematics.

It's strange I'm having trouble finding this. The raspberry pi 3
bluetooth chip is clearly documented at
https://www.raspberrypi.org/products/raspberry-pi-3-model-b/ :

BCM43438 wireless LAN and Bluetooth Low Energy (BLE) on board

It's possible the pi 4 uses the same chip. It's a bcm43xx .