This application note and the related example project shows the implementation of a low-power sampling application using Atmel SAM L21. The device samples a sequence of inputs 32 times per second with an average power consumption of 1.7μA. To ensure a minimal power consumption SAM L-series low-power features are applied, such as main voltage regulator selection, sleepwalking with power domain gating, and utilizing the ultra-low-power internal oscillator. The various techniques for reducing the power consumption will be described in the following section.
The related example project is available as a .zip-file from the SAM L product page1 and is implemented using Atmel Software Framework (ASF). It will be necessary to open the project to see the full implementation as only key parts of the code will be presented in this application note.