NRF52840 Thread example power down 10 mins after USB disconnect

[meetandyhere]

Hello,

I am trying the Thread Cloud COAP Client

<InstallFolder>\examples\thread\experimental\cloud_coap_client

on a NRF52840 PDK. I'm using Thread SDK v0.10.0. The example works as described.

However, when I unplug the board from USB, it goes into some kind of power down mode in approx. 10 minutes and loses connection to the Thread network. I can see LED1 is still on, but it is extremely faint. It is flickering, so trying to connect to the network, but it cannot do so. After a further 5-6 minutes of this, LED1 goes completely off.

I had a few questions about this behaviour:

1. Where in the code can I set the time between USB disconnect and going in power-down mode?
2. I know that the NRF52840 has System ON and System OFF power modes. Where in the code can I set which mode it should go in?
3. Is the behaviour of it not being able to connect to the Thread network when in low power mode expected? If so, can I change this behaviour or is there a fix planned?

Thanks in advance!

Regards

Andy

[meetandyhere]

Thanks for clarifying that. I couldn't find any DFU example in the IOT SDK. The only place i found it was <INSTALL_FOLDER>\examples\iot\tftp\dfu. In the normal SDK, there is a dfu example but no IOT CoAP. Did you mean this example ? <INSTALL_FOLDER>\examples\iot\coap\ipv6\client_observe ?

[Robert Lubos]

I meant DFU example from Thread SDK. You can find it in <INSTALL_FOLDER>\examples\thread\experimental\dfu\client. It uses a copy of IOT CoAP, ported for OpenThread, which is located in <INSTALL_FOLDER>\examples\thread\experimental\dfu\coap. The example itself does not use observe feature though, but you can check the documentation to see how to use it. Optionally, there is an example in IOT SDK (Observer Client) that uses observer feature, so you can use is as a reference for CoAP code. Keep in mind though that IOT SDK examples does not use Thread.