Joined: 21/12/2014 05:56:01
miniwireless has mcp1703 voltage regulator, so as long as you powering circuit through VCC pin you'll be fine with anything from 2.7 to 16V.
That's the safe way.
But if you're trying to squeeze every µA, you may try to remove MCP1703 completely and power your board directly throug 3V3 pin.
as long as input voltage stays ~3V you should be fine. Running atmega outside it's specs is possible, but when the voltage drops below certain threshold (that varies greatly depending on many factors, including temperature) you'll start experiencing undebuggable issues (memory corruption, freezes etc).
And that's where BOD kicks in. Atmega328p has (configurable) brown out detection that shuts down MCU when input voltage is below 4.3, 2.7 or 1.8V.
I'm not sure which value miniwireless boards are shipped with.
Also, read this: http://forum.anarduino.com/posts/list/0/39.page