Wake up at fixed time on lpc812

[martinpare]

I am working with the LPC812.  The microcontroller will be in Power Down mode and it needs to wake up every 5 minutes or on pin interrupt.  The problem I have right now is that with the code I have, when there is a pin interrupt, it will also reset the 5 minutes timer.

I tried reading the LPC_WKT->COUNT register when waking up with the Pin interrupt, so I could restart the WKT timer with this value when going back in Power Down mode, but I always read 0.

How can I do that?

Thank you!

[kerryzhou]

Hi Martin Pare,

    The pin interrupt should not influence the WKT timer.

    When you read the COUNT register, please check this remark in the user manual:

Please read the register twice in succession.

Please try again.

If you still have question, please let me know!~

Have a great day,
Kerry

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