Citric,
Thank you for your reply.
From my perspective it doesn’t make sense why Seeeduino XIAO (the designers) failed to implement easily implementable Low Power operation. I say this because the size and capabilities of the device make very attractive for battery-powered embedded applications.
It is also frustrating that I have spent a significant amount of time trying to implement what appeared to be doable low power library applications for SAMD21.
I’m using it to act as a OLED display controller on a battery-powered device.
If anyone else has suggestions on how to easily implement a low power shutdown and wake-up using external interrupt (serial or digital I/O) I would appreciate the information.
Thank you again for your help.