Unable to scan for Bluetooth devices using nRF52840 DK with nRF Connect for Desktop BLE application

[efischer]

I would like to use the nRF52840 (3.0.1 2023.16) DK with the nRF Connect for Desktop (v4.3.0) Bluetooth Low Energy application (v4.0.4), but I'm running into a problem connecting to advertising Bluetooth devices.

When I first select my connected development kit in the application, a pop up notifies me that the device needs to be programmed. I allow it to proceed, expecting that afterward I would be able to scan for devices and connect to a Bluetooth device, however despite the log's claims that the firmware was successfully programmed to the device, nothing happens and I cannot scan for Bluetooth devices.

I've attached the 2 text files, one is the console output from the nRF52840 DK that fails to scan for Bluetooth devices ('not working.txt') and the other, for contrast, is the console output of the same process but with an nRF52832 (1.2.4 2019.8) DK that does work as expected ('working.txt'). 

Seems to me like somewhere between the switch from the Segger programmer to the nRF5340 programmer, something broke.

 6763.not working.txt

2605.working.txt

[dejans]

Hi,

Did you successfully build and flash you application to non-working device? Which application did you use?

Best regards,
Dejan

[efischer]

Hello, 

I used the Bluetooth Low Energy (v4.0.4) application, the github repo for the BLE application has the following demo:
https://github.com/NordicSemiconductor/pc-nrfconnect-ble/blob/main/resources/screenshot.gif

My understanding based on that demo and what happened when I used the nRF52832 (1.2.4 2019.8) DK is that after allowing the BLE application to program the device with the connectivity firmware, I should be able to click the "start scan" button and connect to available Bluetooth devices. 

However, when I used the nRF52840 (3.0.1 2023.16) DK, nothing happens after allowing the BLE app to program the device with the connectivity firmware. Something must have gone wrong, but I'm not sure what or why. 

Thanks, 
Ethan.

[dejans]

Hi Ethan,

efischer said:

However, when I used the nRF52840 (3.0.1 2023.16) DK, nothing happens after allowing the BLE app to program the device with the connectivity firmware. Something must have gone wrong, but I'm not sure what or why. 

Could you provide more information about "nothing happens"? Is Scan button greyed out, or nothing happens (there are no other devices) when you press Scan?

Best regards,
Dejan

[efischer]

My apologies, the scan button was grayed out and the device didn't show up on the connection map to the right.

I was going to take a screenshot of the issue, but for whatever reason it actually worked this time, I can scan for devices and the nRF52840 shows up as an adapter on the connection map now.

I'm not sure what might have resolved the problem, the only thing I can think of that happened differently this time is that the first time I selected the nRF52840 DK in the BLE application it didn't ask me to program it. I guess it recognized the firmware it had previously programmed it with (which is weird since every time before that if I disconnected and reconnected the device the application would ask to reprogram it), and I still couldn't scan for devices so I opened up the Programmer application and erased the memory (something I'm pretty certain I'd already tried on Monday when I first ran into this issue). When I reopened the BLE application and selected the device the application asked to program it and everything just worked that time. 

Thanks!
Ethan.

[dejans]

Hi Ethan,

efischer said:

My apologies, the scan button was grayed out and the device didn't show up on the connection map to the right.

Thank you for providing this information.

efischer said:

I was going to take a screenshot of the issue, but for whatever reason it actually worked this time, I can scan for devices and the nRF52840 shows up as an adapter on the connection map now.

This is good to hear.

efischer said:

I'm not sure what might have resolved the problem, the only thing I can think of that happened differently this time is that the first time I selected the nRF52840 DK in the BLE application it didn't ask me to program it. I guess it recognized the firmware it had previously programmed it with (which is weird since every time before that if I disconnected and reconnected the device the application would ask to reprogram it), and I still couldn't scan for devices so I opened up the Programmer application and erased the memory (something I'm pretty certain I'd already tried on Monday when I first ran into this issue). When I reopened the BLE application and selected the device the application asked to program it and everything just worked that time. 

After successful programming operation, I would expect as normal behavior that there is no need for programming the device again. The device should be automatically recognized by the Bluetooth Standalone application.
In your case, I assume that erasing the flash helped in resolving the issue. If similar issue appears again, you could also try to recover your device using "nrfjprog --recover" command. If you encounter this issue again, please provide reproducible steps for us to look into and try to replicate the issue. However, I hope that everything will work for you in the future, and you will not see this issue again.

Best regards,
Dejan