@mardah oh... you mean pin change system, not extint. You can use it of course.

@GertSanders ok, strange. standard pin headers fit for me only into FTDI and ICSP pin holes. Into the other two 8 pin rows it does not fit.

@scalz Voalá! 5.2uA consumption with flash in Ultra Deep Power-Down! Will have to test OTA functionality though (waking up from Ultra Deep Power-Down), but in my experience this is going to be very hard on a coin battery.

@JahFyahh - I still haven't managed to et round to it. I've been really busy since this project and its still hectic here. I'm sure i read a few reviews somewhere, here or google. Not sure.