Hello,
I would like to test this project
https://www.seanet.com/~karllunt/sdlocker2.pdf
The MCU I have is a TQFP ATMEGA328P-AU
I would like to make it really portable and I have not got the charge pump IC, so I consider the different battery options.
Initially a cr2032 (or other button cell) was thought to be good but these are rated at 3v only. If I had a little charge pump circuit out of common ICs, this could be ideal.
Another option could be the A23 battery with a coltage divider, but I am not sure if this has enough current for the micro.
A third option (although a bit larger, but more common) would be to place 3x AAA rechargeable batteries to get 3.6V (eneloop, low self-discharge)
Another option is to use two CR2016 in series to get more voltage.
I also need a verification of the current drawn by the micro so that I can see the battery power option.
Could you please help a bit?
Any suggestions would be appreciated.