For the application to start using an instance of the module, it must call the DRV_BM64_Open function which provides a driver handle to the BM64 Bluetooth driver instance.

Note:

It is necessary to check the status of driver initialization before opening a driver instance. The status of the BM64 Bluetooth Driver can be known by calling DRV_BM64_Status.

Example:

case AUDIO_STATE_OPEN:
{
    if (SYS_STATUS_READY == DRV_BT_Status())
    {
        // open BT module, including RX audio stream
        audioData.bt.handle = DRV_BT_Open(DRV_IO_INTENT_READ, DRV_BT_PROTOCOL_ALL);
        if(audioData.bt.handle != DRV_HANDLE_INVALID)
        {
            audioData.state = AUDIO_STATE_SET_BT_BUFFER_HANDLER;
        }
    }
}

Event handlers are functions in the user’s code that are used as callbacks from the driver when something occurs that the client needs to know about. 

The function DRV_BM64_BufferEventHandlerSet is called by a client to identify a buffer-related event handling function for the driver to call back. The prototype for the callback is defined by DRV_BM64_BUFFER_EVENT_HANDLER. The callback will be called with the event DRV_BT_BUFFER_EVENT_COMPLETE. 

The function DRV_BM64_EventHandlerSet is called by a client to identify a general event handling function for the driver to call back. The prototype for the callback is defined by DRV_BM64_EVENT_HANDLER. 

For audio applications, the callback will be called with events such as DRV_BT_EVENT_VOLUME_CHANGED, DRV_BT_EVENT_SAMPLERATE_CHANGED, and DRV_BT_EVENT_PLAYBACK_STATUS_CHANGED. For BLE applications, the callback will be called for events such as DRV_BT_EVENT_BLESPP_MSG_RECEIVED and DRV_BT_EVENT_BLE_STATUS_CHANGED. 

Example:  

case APP_STATE_SET_BT_BUFFER_HANDLER:
{
    // note generic version of calls (DRV_BT instead of DRV_BM64) are used
    DRV_BT_BufferEventHandlerSet(appData.bt.handle, appData.bt.bufferHandler,
                                 appData.bt.context);
    DRV_BT_EventHandlerSet(appData.bt.handle, appData.bt.eventHandler, (uintptr_t)0);
    appData.state = APP_STATE_CODEC_OPEN;
}