XC6190 is a voltage detector (1.47v trigger voltage) with what it claims is just a 10na quiescent current. Sounds pretty good to me:
https://www.mouser.com/datasheet/2/760/XC6190-837296.pdf
@NeverDie Perhaps but the design is a bit too simple and unoriginal. I'd have to clean up the files a bit and I haven't touched Eagle since I made this board several years ago.
@fets So far, I have only built the 5x5 board (but the others should be schematically identical). The only issue I have found so far is that I cannot get the ISP port to work. But I have checked and I have an identical setup on the 1.0 board and that worked, so I suspect the programmer is too weak to drive the net on this one. So it is not a board-issue per se, and might only be an issue on the 5x5 board as routing is the most complex on that one due to the size.
Hope will test the new version of this universal board soon. Now it has additional inexpensive accelerometer, magnetic sensor, led, reset button, multifootprint for lora/hw/cw radio without adapter and improoved 4layers design
In deep Sleep the cunsumption is below 19µA, but i have to send with PA_MAX. On some Windows the open/close frequency is verry high, so the battery is to fast emty.
The CR2032 is good, but i want more "lifetime"
Thanks again, learned a lot... I decide to give a try there, I also had a look on some components' datasheet and seems to be what I need... Let's see, if end up getting the boards I'll publish a review here later.
