nRF connect for mobile on Android unable to discover nRF52840

[SubhanRVL]

Hi All,

I hope this message finds you well. I am reaching out to report an issue with my custom board design utilizing the nRF52840, programmed with the Nordic UART Service example.

The board can be successfully discovered through the nRF Connect for Desktop using the nRF52840 dongle as a central device. However, when tried with the nRF Connect for Mobile application on Android, the application is unable to discover the board.

Attached, please find the below screenshot showing the nRF52 dongle making a successful connection with the board.

I have experimented with various settings combinations on the nRF Connect for Mobile application, but none have proven effective in resolving the issue.

Your insights and assistance would be highly appreciated. If anyone has encountered a similar problem or has suggestions for troubleshooting, please share your experiences.

Thank you in advance for your support.

Regards,

Subhan

[Joakim Jakobsen]

Hi. 

That sounds strange. 

custom board design utilizing the nRF52840, programmed with the Nordic UART Service example.

Have you tested with other boards, i.e the nRF52840-DK? Do you see the same behavior there?

Which version of the SDK are you working with?

However, when tried with the nRF Connect for Mobile application on Android

Could you also add phone model and OS version?

_______________

Have you made sure that the device is disconnected from the dongle and nRF Connect for desktop - BLE app before you tried connecting to your smartphone?

Br, 
Joakim

[SubhanRVL]

Hi,

Thanks for your prompt response. Here are the details:

1) We conducted further tests using the Nordic UART Service example running on the nRF52840 dongle. Surprisingly, both the PC and mobile successfully discovered the board. To clarify our setup, we have two nRF52840 dongles: one acting as a central device, and the second one programmed with the UART example.

2) The example is based on nRF Connect SDK v2.5.0.

3) Regarding the mobile application, I have tested it on

• Samsung Galaxy A54, Android version 13.
• Samsung Galaxy S22, Android version 13.
• OnePlus 7T, Android version 12.
• iPhone SE iOS version 16.6.1

4) We also tried the connection on a ThinkPad T480 laptop with inbuilt Bluetooth using Acrylic BLE Analyser. Both devices—the dongle and our custom board—were successfully discovered with no issues.

5) We also tried with a second laptop, ASUS Zenbook, with intel Bluetooth built-in(VID 8087, PID 0026) using an Acrylic BLE Analyser. Surprisingly, this laptop can only discover the nRF52840 dongle but not our board.

6) For your reference, we are using nRF52840 QFN48 6 x 6 mm package on our board whereas nRF52840 dongle uses QIAA package. 

For your reference, I have enabled the following configuration settings:

• CONFIG_CLOCK_CONTROL_NRF_K32SRC_SYNTH=y

Despite these tests, the nRF Connect for Mobile application still faces difficulty discovering our board. Your insights on this matter are greatly appreciated.

Regards,

Subhan

[SubhanRVL]

Any update on this, please?

[Joakim Jakobsen]

Hi.

Sorry about the long delay. I will try to get back to you by the end of day today.

BR,
Joakim

[SubhanRVL]

Hi Jaakim,

I appreciate the update. Just to highlight, it's a very urgent issue, and I'm counting on your input. I look forward to hearing from you by the end of the day.

Regards,

Subhan