XIAO MG24 Sense RTC_DATA_ATTR issue

[msfujino]

@Dave_Reese

All I know is LowPower.attachInterruptWakeup() doesn’t seem to work, and nobody talks about it with this microcontroller. There isn’t any info on using the IMU as an interrupt either.

See the link below for the wake-up pins.
Attached is a sketch that confirms it works.
MG24_XIAO_DeepSleep_ExternalWakeup.zip (2.1 KB)

Unfortunately the IMU interrupt is not connected to the controller.

DeepSleep bricks XIAO_MG24

Information on wake-up pins. The 8 pins that can be used for wake-up from EM4:DeepSleep seem to be PC0(ESCAPE), PC5(SCL), PC7(RX), PA5(MOSI), and back side PB1, PB3, PD2, PD5(IMU_PW). Reference Manual, 24.3.12.3 Pin Function Tables, Table 24.3. GPIO Alternate Function Table PC0 is also defined as ESCAPE to avoid bricking. It is not impossible to use it as ESCAPE function when it is LOW for a long time and as a wake-up function for a short time.