Custom A2DP source bluetooth application.

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JaKo_4554081
Level 3
Level 3
25 sign-ins 10 replies posted 10 sign-ins

Hi.

I am working on a project involving A2DP source application. For this task i've bought CYW20719 eval board and DSP which provides audio package via I2S (mixed signals from 8 microphones). I have made some changes in watch example and managed to stream audio from DSP, but there is some delay (it is not my concern for now). However in the project i can't control the app via HCI. I started developing custom a2dp source bluetooth app with the use of bluetooth designer. Once the template has been generated i've copied some functions and after hours of struggling i have managed to compile and run the app, but after trying to connect to mono receiver i get "Key retrival failure". The code got really messy and i don't really know what's going on inside of it.

Because of the HCI control it is really hard for me to figure out whats going in in the app, i am basicly blindfolded. Does anyone have any guide for a2dp source application? Or can provide any help which would allow me to write custom app?

BR

Jakub

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1 Solution

Hi Krzysztof,

I think the quick way to realize the function is to check the HCI commands from the PC. Then you can find the corresponding functions and call these functions in a timer callback or button interrupt callback.

For example, you can find the inquiry command in the HCI_CONTROL_GROUP_DEVICE and the function hci_control_inquiry( *p_data );. You can call this function in a button callback and then initiate the connection.

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3 Replies
Owen_Zhang123
Moderator
Moderator
Moderator
5 questions asked 500 solutions authored 250 sign-ins

The HCI control uses WICED HCI Control Protocol. You can refer to the command format in the doc/WICED-HCI-Control-Protocol.pdf.

You can use the Client Control to control the device first.

Hi OwenZ,

The problem is how to write audio source application with control algorithm inside the CYW20719 without using UART HCI.

I have a similar project on the table and need some guidance on how to control/establish the connection and then start a stream from inside the Cypress device.

Now I am able to do that controlling the app through UART HCI from PC. But the goal is to use just the CYW20719 for BT as well for whole control/business logic application (NO EXTERNAL uC or PC).

Please, could you give any hint of how to do it? Any examples?

BR

Krzysztof

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Hi Krzysztof,

I think the quick way to realize the function is to check the HCI commands from the PC. Then you can find the corresponding functions and call these functions in a timer callback or button interrupt callback.

For example, you can find the inquiry command in the HCI_CONTROL_GROUP_DEVICE and the function hci_control_inquiry( *p_data );. You can call this function in a button callback and then initiate the connection.