How do I use printk with NRF52840 dongle using NCS Zephyr? The nrf SDK has the NRF_LOG_BACKEND_USB_ENABLED option that could be used. The NCS does not have any examples.

[Sudhir]

I tried the logger examples in the Zephyr that work on the DK but not on the dongle. I tried to change the Kconfig options using Segger to enable the logger but those options are not available. If I can see how "Hello World" can be modified to run on the dongle and do the print, that will help. I can run other functionality on the dongle including Bluetooth coded_phy.

[Hakon]

Hello,

the nRF52840 dongle does not have a virtual COM port, so you will need to use the USB peripheral to send the log output. There is no config option to route the printk data to the USB peripheral as far as I know. You can try this sample and see if you can run it on the dongle. Then it should be possible send the log data on the USB.

[Sudhir]

Thanks. That sample is deprecated by the connectivity bridge. So I wanted to get an example that is proven and works on the dongle for sure. The board overlay file will be critical, I think.

[Hakon]

Sudhir said:

So I wanted to get an example that is proven and works on the dongle for sure.

 Have you tested that the sample doesn't work?

[Sudhir]

The sample doesn't even work on the DK!! It gets stuck at Wait for DTR. Would you mind trying it out?

*** Booting Zephyr OS build v2.4.0-ncs2 ***
[00:00:00.256,835] <inf> cdc_acm_echo: Wait for DTR

[Hakon]

Sudhir said:

Would you mind trying it out?

 

This was on the DK, but it should work the same on the dongle.