A single AA battery provides voltages of 5V or 3.3V for hardware prototyping.
This tiny board allows you to bring the power to your project, and not the other way around. Bring your micro to the sensor without running wires! A single AA battery is used to provide breadboard power of 5V or 3.3V (or other voltages by tuning the feedback resistors). A boost regulator provides the voltage.
BooSTick – small AA voltage booster – [Link]