@Richard_Wright just wondering if you had any luck with this.
I’m looking to do the same.
The SAMD51 has low power sleep
I’ve had it working before, but its now not working when using on the Wio Terminal.
There are two aspects - reducing the power consumption, and coming out of reduced power consumption
Typically this is talked about as
a) turning off all peripherals, deciding how long to sleep and setting an RTC alarm, going to low power sleep
b) on RTC alarm waking up, and restoring all needed peripherals
A sleep part is explained here for a SAMD21 Home · BitKnitting/wakey_circuitpython Wiki · GitHub
The SAMD51 is similar, but not sure how similar
For a wakeup everyday - there is an example GitHub - Seeed-Studio/Seeed_Arduino_RTC: When your project needs to be unplugged, how to keep the time counting? This library can help you set up the current time. examples alarm_samd51
Ideally it would be something like this, though it probably needs customizing for SAMD51 & Wio Terminal “EnergySaving.h” GitHub - bcmi-labs/arduino-library-energy-saving: Energy saving Arduino library features for corte-m0+
sample of sleep and wakeup on RTC using seeeduino xiao and Arduino-IDE · GitHub