Power consumption

First of all, awesome work on this hardware and core!

Secondly, Power consumption:
I've been testing with this core, and it seems that there is significant quiescent power consumption, regardless of actual hardware.
On the Feather nRF52 board using the beacon example I'm seeing 13mA average, and thats with the connection LED disabled.
Using a Red Bear Nano 2 (with their bootloader) but the same compiled hex, and powering off the VDD pin (3.3v) I'm still seeing ~6mA.

Using the Red Bear Nano 2 and their beacon code, I can get average power consumption below 20uA!

I'm hoping to dive in and do some deep level debugging with this core, but need to get the power under control relatively quickly for a prototype.

Any thoughts or suggestions would be helpful!

Thanks and keep up the great work

Start by reproducing the reported power measurements with the beacon example on the Feather nRF52 and Red Bear Nano 2 boards. The payload names no source files or tests, so trace the core's power-related behavior and compare it with the reported sub-20uA beacon result. Done means the excessive quiescent consumption is explained and reduced or a documented limitation is established.

Written by the indexing model from the issue text.