CSRA64215 pairing with button: device can't be found

[jmibk]

Hi,

I'm doing some tries with a CSRA64215 module that I want to use as a BT to I2S device because it says, that it supports AptX lossless audio.
The default setting of the modules is that pairing can be done on every situation without any time limitations. In short, you can hijack the audio output.

So, I twiddled around with the PIO pins and these mappings, that I can start the pairing mode by applying 3,3V to pin PIO18.

Now the problem: The CSRA64215 goes into pairing mode after a few seconds after powering it on. My mobile and a iPad can find the bluetooth device and they are also able to connect to it.
After 20 secs the CSRA64215 goes into whatever standby mode ("Connectable"). After setting the PIO18 pin high a second (approx) it goes back into pairing mode (the fast flashing led shows pairing mode).
During that pairing, none of my bt enabled devices can't find the CSRA64215 anymore (they are not currently connected to the CSRA64215, so that they behave like "new" fresh devices).

Anyone any idea whats going wrong?

Here some screenshots of the CSRA tool:


Showing the behavior on power on - during that period it shows up in the bt list of devices.


Showing the 20secs timeout.


The connection of the button with the pairing mode (this works well).

Here's the file dump of the CSRA64215.
http://www.audiowerk.at/downloads/temp/eev/csra64215/20201016_5_dump.psr

If you need more information, please ask.