In order to investigate the low power modes and techniques for an STM32L0 class microprocessor, I've build a temperature and humidity display using an STM32L031F6 uC, an SI7021 I2C temperature/humidity sensor, and a Waveshare 1.54 inch black, white, and red ePaperDisplay. Starting with a straight-forward, non-optimized version of the software, this project will investigate and document the various power savings techniques that can be applied to the system, in order to get the power usage of the device down to a level that (hopefully) makes it practical to run off of a CR2032 coin cell.
Track the progress on Hackaday.io