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