I have a project built on the 802.15.4 MAC sensor FreeRTOS example for a KW41Z from the MCUXpresso SDK 2.2.0. I am noticing that occasionally the processor will wake from LLS3 almost immediately after going to sleep. I was able to trap the LLWU_ISR when this happens and all LLWU flags are 0 so I do not know what is trigger the wake and ISR.
In the code I removed any pin sources and in this mode, only the LPTMR is a LLWU source. If I look at the LLWU registers at the start of the LLWU interrupt, all registers are 0 except LLWU->ME is equal to 1.
Any ideas what would cause this?