1 year, 1 month ago.

SMT32L4 GPIO Needs 3 ms to Cause Wake from Deep Sleep


I have a NUCLEO_L433RC_P and want to use MBED_TICKLESS. One of the wake-up sources needs to be a GPIO.

I'm creating an InterruptIn and adding a fall handler:

InterruptIn interrupt_in(PB_4, PullUp);

If Mbed OS has entered deep sleep it appears the GPIO must be low for 3 ms in order to wake-up the MCU and for the interrupt to fire.

In other words, for pulses more than 3 ms what I trying appears to work but less than 3 ms and nothing happens. 3 ms seems like a long time to me!

Without MBED_TICKLESS defined a much shorter pulse will cause the interrupt to fire.

Does this mean anything to anyone?

Any thoughts greatly appreciated.

Regards, Matt

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I've just discovered and

I had thought that this behaviour was something to do with the STM32L4, which is why I posted here, but I now suspect that it is something to do with the InterruptIn implementation.

I shall look into these issues more closely and see if they are transferable to STM32.

posted by Matt Brown 11 Jul 2018

I've opened an issue

posted by Matt Brown 12 Jul 2018
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