I needed something to control an ESP32 in a sleep/wake cycle, I found the ESP to be inaccurate when asleep for long periods, so I decided to use an external clock chip to generate an external interrupt. I tried using a DS3231, but run into a lot of trouble with the Alarm behaviour not working, after a lot of experimentation I decided the problem was due to Chinese copy chips not working correctly. So I tried using the Pimeroni module using an RV3028, this works, and works well. The device has very low power consumption and supports unix time. In my application, I'm mimicking the behaviour of the initial version of the ThingsOnEdge Cricket module.