Waking XDot via UART

[Matt Briggs]

I am interested in waking the UART from sleep (stop mode) and receiving characters then going back to sleep say after 10 seconds. I have tried setting the dot->setWakePin(UART1_RX) and this does indeed wake the uC up but also seems to make Serial.readable always true (and reads a NUL char) directly after exit from sleep even from other unrelated interrupts. This causes problems with the rest of my serial implementation.

The work around I am currently pursuing is to make UART1_RX an InterruptIn which will trigger a flag in the main loop to configure the serial port then after the 10 second timeout the Serial class is destroyed and the InterruptIn irq re-enabled.

Is there a better way of implementing this functionality?

• This topic was modified 7 years, 6 months ago by Matt Briggs.

[Mike Fiore]

Matt,
When you call mDot::setWakePin() and go to sleep, the Dot library is internally creating an InterruptIn object on that GPIO. So your solution would look basically the same whether or not you used setWakePin().

* delete your serial object
* set the wake pin or create your InterruptIn
* go to sleep
* wake on serial
* delete InterruptIn if you created it (Dot library handles this if setWakePin was called)
* create serial object
* RX serial data

Hope this helps!

Cheers,
Mike

[Matt Briggs]

Thanks for the thoughts Mike.

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