CC8531: Why the devices cannot pair while sample rate is 32k?

Hi M-W,

I enabled 32k and 48k sample rate separately, the former case devices(1 master & 1 slave) couldn't pair, but the latter could.

According to the Audio Streaming view of slave, the sample rates it supports are 32k, 44.1k and 48k. What I could do is to change master's sample rate, but why different sample rate could influence their pair process.

Best wishes,

SeanOY

Hi Sean,

A think that comes to mind is if the setup of the audio interface on the Slave side fails when trying to switch to 32kHz sample rate. I could see you supplied your own audio device, have you been able to verify the setup sequence you use for it in all modes?

Hi M-W,

What do you mean about "all modes"? :) Do you mean that different "sample rate" while other configurations are the same?

Best wishes,

SeanOY

Hi Sean,

By "all modes" i mean potential different setups for the audio codec (I did not look closer at this in your case). If you have tried with the master setup to support both, then I would not expect any direct issues pairing them. Do you have any development kit that you could try it out on using the provided examples? 

Also,

If you have external clock into the master side, make sure this is 32 kHz when trying to use this mode. The clock should match the device expected sample rate otherwise you could run into issues like this.

Hi M-W

I'm sure that the other setup except "sample rate" of master and slave device is the same. Moreover, I only have two CC1312 DK boards.

Best wishes,

SeanOY

Hi  M-W,

I test it with two official development boards, it shouldn't cause problems about clock.

Best wishes,

SeanOY

Hi Sean,

Could you maybe elaborate on which HW you are testing on exactly and how it is setup when you perform these tests? I'm looking for HW, connections, SW (you already attached this on top but if there is any updates to this). 

How do you verify them not wanting to pair, are you tracking any status messages on either side?

Hi M-W,

Master board uses DSP as external audio device and slave board uses WM8988. The external crystal frequency of the former device is 48 MHz, am i choose the wrong crystal?

I am sure that I use the same setup while testing them, I judge whether they are connected by observing the blinking status of the network indicator LED.

I use command get_status() to track, the difference status of them is "EVT_VOL_CHG". Also, when they're connected, they'll blink at the same time and frequency.

Best wishes,

SeanOY

Hi M-W,

I've asked the engineer who wrote the relevant codes for DSP, he configured the MCLK as 24.576 MHz, sample rate as 48 kHz and BCLK as 3.072 MHz.

Now we can draw a conclusion, the issue is the setup of DSP's sample rate.

Thank you :)

Best wishes,

SeanOY