I am using WICED SDK 6.4 on CYW2076 Bluetooth Evaluation Kit CYW920706WCDEVAL evaluation board and unmodified hci_audio_gateway demo app, controlled by WICED Control application from the SDK. I am connecting an HFP-capable headset (Jabra Talk 25 or Jabra BOOST) to the eval board and opening an audio connection using WICED Control application. Then I'm checking presence of the PCM audio on the eval board's I2S interface, using Ellisys sniffer. The I2S interface has its default settings, i. e. it is the master. This works pretty well - the PCM and OTA audio streams extracted from the Ellisys trace are identical.
Now I'm making a simple test - I'm taking the Bluetooth headset with me and going some meters away from the eval board, then I'm going back. In order to get some audio on the microphone, I'm using portable audio player that is being carried close to the Bluetooth headset. The traces show that although OTA audio is always present, the PCM audio is not present anymore after I come back. And the whole system (BT headset + eval board) remains in this state until one of the participating devices is forced to disconnect Bluetooth and then reconnect.
It is understandable that the audio gets distorted or even lost when the headset is moved away, but why doesn't it recover when the headset is being brought back?
WICED Studio Bluetooth