The Adafruit TPL5110 Power Timer is a stand-alone breakout that will turn any electronics into low-power electronics! It will take care of turning your project on/off using a built in timer that can vary from once every 100ms up to once every two hours. Basically, the TPL will turn on periodically, adjustable by potentiometer or resistor, and turn on your project's power. It will then wait until a signal is received from the project to tell the TPL that it can safely turn off the power.