Android version 9 cannot find my device

[Jenzo]

I am using  nRF52832 on my device. I have used SDK13 and softdevice 4.0.5.

On any iOS devices I can scan and connect in the nRFConnect app.

On an older Samsung Galaxy S5 running Android version 5, I can find my device during scan and I connect with the nRFConnect app.

However on a Samsung A20 with Android version 9, I cannot find my device in the nRFConnect app. I have turned on location service and given other necessary permissions, but my device is not being scanned!?!

I am running the latest versions of the nRFConnect app.

What could be the issue?

[Ivan Herrera]

When you open the nRFConnect app, press the top left drawer button and click on "Device information", does it indicate that you have support for most of the features with a green YES? 

[Jenzo]

yes

[Ivan Herrera]

Have you had a look at this thread Jenzo?

https://devzone.nordicsemi.com/f/nordic-q-a/57079/samsung-phone-doesn-t-allow-some-beacons/

Maybe adding some information there might help the Nordic team figuring out what's happening?

[Jenzo]

Hi Ivan,

I have read through the ticket and tried to change the clock to the following:

#define NRF_CLOCK_LFCLKSRC {.source = NRF_CLOCK_LF_SRC_RC, \
.rc_ctiv = 16, \
.rc_temp_ctiv = 2, \
.xtal_accuracy = 1}

But it doesn't work.

Any other clue to the problem?

What other information do you need besides the information stated in the entire ticket?

Regards
Jens

[Ivan Herrera]

Just a disclaimer. I'm not a Nordic employee. I just have similar issues and would like to see this resolved as well. If you go to the android Bluetooth settings and go to "Pair new device". Do you see the device popping up there?

[Jenzo]

Hi Ivan,

Yes I can see it in nRFconnect. And when I run my app on a Nordic dev board I can find it in my app, so it must be an antenna or fine tuning problem (let me remind your that when designing our product my antenna design was approved by Nordic staff). But how come Samsung is developing smart phones with Bluetooth modules that vary so much in quality? Naturally all Apple products work and the higher quality Samsungs like the S10 works perfect with my product, but the A40 and A20 simply doesn't work!

Just wondering if I could fix it with some settings in the softdevice.

Bluetooth is a standard. It should not be allowed to differ from the standard. 

Regards

Jens

[Ivan Herrera]

I'm not a BLE-expert but like you said before that you're receiving at -50dBm so I'd say the antenna is working fine. You also mentioned that when you run it on the devkit it is also being received fine, thus there aren't any issues with the Bluetooth-permissions on the phone of that sort. 

I'm just speculating here but wouldn't it be possible that the crystal-oscillators are not fully within specs, resulting on some BLE-chipsets not being able to decode your message? Do you have both the 32Mhz and 32Khz crystal on your custom board, or just the 32Mhz one? 

[Jenzo]

I have both crystals on my board. 

[Jenzo]

Hi Ivan,

Why did you ask if I had both crystals on my custom board?

Please respond.

Regards
Jens