Issue with getting clean audio

[tnk-rin]

Hello!
Not too sure if this or the Issues is the best place to ask about this but I figure its best to ask since I've been wracking my brain on this for too long haha!
I've recently purchased an ESP32 and some PCM5102 DACs to build a BT receiver for my car, and wiring it up as per the examples gives 2 different results depending on which example is used. If I use the bt_music_receiver_simple.ino example, it will play audio for about half a second then freeze on the last several frames. If I use the ESP32 I2S API example in the Readme, it plays audio without freezing but instead lags every quarter or half second.
I then went to try the Espressif example, and got the same result with lag every half second or so. Using the serial monitor though yielded this:



I'm not well versed in ring buffers so I'm not sure how this all works, but it seems like its having issues maintaining a buffer for the DAC. I'm using a Samsung Galaxy Note 9, if that's relevant, and the issue springs in both streamed and locally played music.

[tnk-rin]

Adding onto this, here's a screenshot of the waveform to give a better idea of what its doing.

[pschatzmann]

This does not make any sense to me: bt_music_receiver_simple.ino does not use any ringbuffer! bt_music_receiver_queued.ino however would.

I can't reproduce your issue, so double check the software versions and your cables and/or try with another microcontroller.
And finally make sure that you don't mess up the audio output by logging information.

Also try with a different A2DP source (mobile phone) / application to rule out that the issue is coming from there

[tnk-rin]

Oh interesting! I have suspicions that my DACs are the issue as the internal DAC on the ESP worked perfectly.

Thanks for the help!

I did have some success with the queued examples but it still had some audio errors.

[pschatzmann]

What DAC are you using ?
To test it just try with a simple sine output test case.

If the output using AnalogAudioStream is working perfectly, then the issue is really the external DAC...

[tnk-rin]

I'm using these PCM5102 modules off of Amazon: https://a.co/d/9giCel4

I'll try the sine example you listed and put any updates here.

[pschatzmann]

Did you follow the information provided in the dac documentation ?

If your solder bridges are not set to the recommended values, you need to make some more connectsions....

[tnk-rin]

I did use the External DAC documentation, all of the bridges are correctly wired up. Sine example ended up doing the same thing as the A2DP examples.

Definitely looks like the DAC is the issue.