Can i power an arduino uno board from a 2.3V super capacitor

MarkT:

mirith:
You can probably power the ATMega328. It will go down to 1.8V at lower speeds.

You'll need to reprogram the boot-loader to go this low as the standard bootloader
for has the brown-out voltage set at 2.7V

Just a simple edit of the boards.txt board entry fuse value and then reburn the bootloader, no?