Sometimes we want our projects on, but sometimes we want to turn them off for a while to save power. The SparkFun Nano Power Timer will run while only consuming minimal power (approximately 35nA) and turn your project on after a set amount of time. When you are done polling your sensors, posting data to the web, writing to your logger, or planning world domination, your microcontroller can tell the Nano Power Timer to turn off the power. No more running your microcontroller all day when you only want to read the ambient temperature once per hour.
The TPL5110 delay is configured with the use of resistors. We've added a six-way DIP switch to select one of the five preinstalled resistors. The sixth switch is attached to a pad to add your own PTH (or SMD) resistor. The delays associated with the preinstalled headers are shown on the bottom of the board for quick setup. Additionally, you can select more than one switch to combine the resistors in parallel (up to 26 options not including the custom resistor), check out the hookup guide for a nice chart as to the total resistance and corresponding delay for each combination.
The Nano Power Timer can handle voltages between 1.8V and 5.5V as well as current up to 1.1A with times from 100ms to two hours (preconfigured settings range from 30s to 2h). You will find a button on the board which will allow you a quick override to the delay so you can turn your project on whenever you like.