That project incorrectly runs the Nano on 3.7V. It's out of spec, but the maker probably found that it worked and plowed on... but you could do it safely with a 3.3V Pro Mini.
That project incorrectly runs the Nano on 3.7V. It's out of spec, but the maker probably found that it worked and plowed on... but you could do it safely with a 3.3V Pro Mini.