Asset Tracker 2 with eDRX and PSM settings

[JackW]

We are developing a product that will use Asset Tracker 2 and Nordic's nRF Cloud.

We want to take advantage of the power saving offered by the LTE eDRX and PSM modes.  We are trying to sort out how Asset Tracker 2 sets either eDRX or PSM timer settings, and what the relationship is between those settings and the 'activeWaitTime' that is part of the device's configuration.

So, specifically, our question is:

1. Does Asset Tracker 2 use a default eDRX or PSM setting?  Which one? What are the timer settings?
2. How can those settings be changed?
3. What, if any, is the relationship between whatever either the eDRX or the PSM settings are and the 'activeWaitTime' time setting that is part of the device configuration?
4. How can we determine which setting, either eDRX or PSM that the device is currently set to?  For example, if I use the AT+CPMS? command the response is: +CPSMS: 1,,,"11000001","00001010", indicating the PSM mode is enabled, and if I use the  AT+CEDRXRDP command I get the response +CEDRXRDP: 4,"0001","0001","0001" which indicates the eDRX is enabled.  But they can't both be on at the same time on the same device.  So how do I know if eDRX is currently being used on the device or PSM?

Thanks in advance for your help!

[JackW]

Thanks Achim.

Are these in the NordicSemiconductor/asset-tracker-cloud-firmware-aws repository on Github?  I can't find a "nrf/lib" folder in that repository.  Maybe I'm not lookingin the right place.

[Achim Kraus]

That's the "app-only" part. To build the app, you need zephyr and the sdk-nrf. The west tool will fetch them all based on the west.yml.

To see the files on github, you may browse https://github.com/nrfconnect/sdk-nrf .

To search for something e.g. LTE_PSM_REQ_RPTAU it's easier when the project and the two other parts are already checked out locally.

prj.conf - PSM

You may use the "nRF Connect for Desktop" "Toolchain Manager" to install all required source and tools. After installation, open the sh via that toolchain manager and then you will see the "nrf"  folder. Under "applications" you will find the tracker, and under "lib" you may search the settings, just if your interested in their documentation. If you search the "*.prj" files in the nrf/applications/asset_tracker_v2 you will see the current values.