Device not detected with some phones

[RocioMG]

Hello,

I am having issues detecting my board with some phones. I have tested it with a Samsung Galaxy S8+, Android 9, and with android 5.1.1. However, I can't detect it with a Nokia 1 Plus (android 9) or Alcatel 1x (Android 8.1). Any ideas about why this could be happening?

Thanks!

[Kaja]

Hi,

could you tell me what the load capacitance, CL, for your 32 MHz crystal is?
and what value you have chosen for the load capacitors?

Best regards,

Kaja

[RocioMG]

Hi Kaja,

The load capacitors are 12pF and the CL is 8pF.

Best regards

[Kaja]

Okay, 

this should in theory be correct, but it is most likely the crystal accuracy that is a bit of. 
Could you measure the crystal/freq. accuracy? 

Best regards,
Kaja

[RocioMG]

Hi,

I'm quite new working on this, could you tell me how to measure the freq. accuracy?

The board is also working in other phones with different Android versions.

Thank you

[Kaja]

No problem, 

you can have a look at our white paper RF measurments ch. 4 freq accuracy. Also see ch. 3 in this white paper. 

If you don't have he equipment needed, I can do the measurements for you. 

Best regards,
Kaja

[RocioMG]

Hi Kaja,

I don't have the hardware needed to do that testing.

I just realised I didn't specify I'm using the nrf52832 SoC. I have also tested the software on the nordic development kit and I'm observing the same behaviour, only some phones can detect it.

Best regards

[Vidar Berg]

Hi,

I would say it's probably not HW related as you see the same result with the dev. kit. Are you using the nRF connect app on android to scan for the device? And do you have a custom FW running on the device?