How to configure to wake up from SYSTEM_ON and SYSTEM_OFF using RTC2 (periodically) and from GPIO pin change

[V.Lorz]

Hi,

I need to configure an nRF52832 to wake up periodically from SYSTEM_ON and SYSTEM_OFF and, also, when a GPIO pin changes.

Where can I find sample code and docs for this?

I'm using nRF Connect SDK version 1.9.1 and Visual Studio Code.

BR

[Simonr]

Hi

First off, to clarify. When the nRF52832 (or any of our devices are in "system OFF") the CPU and all peripherals are completely turned off, so it can't be waken up periodically from the RTC in system OFF mode. That will only be possible in system ON mode. To wake up the device from System OFF mode you have to use an external source, like when a button is pressed or have an external timer going that trigs a GPIO every X amount of time.

We have a sample project showing how you can put the nRF5x series devices into system OFF here. 

We don't have an official example showing how to use the RTC in the nRF Connect SDK at the moment, but one of my colleagues made this example for the RTC on the nRF91. Since the same driver is used in the nRF52 series, it should be pretty straight forward to modify to work on an nRF52832 as well. Alternatively, you can check out the Zephyr kernel timer that can perform an application-defined action after a specific time limit is reached.

Best regards,

Simon

[V.Lorz]

Simonr, please find here the data captured and the project for reproducing the behaviour.

It was not possible for me to compile neither the original project nor a new project created using the sample as a template. This project uses snippets from the original code.

BR

hello_off.zip

power-off-capture-data.zip