Get a 3.3v nano / nano pro. To run it at 3.3v you'll need a boost regulator (your 3.7v battery will drop to a lower voltage, which requires a boost switching regulator) that will bypass the onboard regulator.
Get a 3.3v nano / nano pro. To run it at 3.3v you'll need a boost regulator (your 3.7v battery will drop to a lower voltage, which requires a boost switching regulator) that will bypass the onboard regulator.