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Bluetooth AVRCP API

The openvela Bluetooth AVRCP (Audio/Video Remote Control Profile) interface supports playback control, track information queries, and more.

Header files: #include "bt_avrcp.h", #include "bt_avrcp_control.h", #include "bt_avrcp_target.h"

openvela Implementation Notes

• Dual-role support: Controller (control side) and Target (target side)
• Features: Play/pause/skip tracks, volume control, track information retrieval

Synchronous Interfaces

bt_avrcp_control_unregister_callbacks

bool bt_avrcp_control_unregister_callbacks(bt_instance_t* ins, void* cookie);

Unregister callback functions and stop receiving state change notifications.

Parameters:

• ins Bluetooth client instance.
• cookie User context.

Returns:

Returns the callback cookie on success, or NULL on failure.

bt_avrcp_control_get_element_attributes

bt_status_t bt_avrcp_control_get_element_attributes(bt_instance_t* ins, bt_address_t* addr);

Get media element attributes from the remote device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.

Returns:

Returns BT_STATUS_SUCCESS on success, or an error code on failure.

bt_avrcp_control_send_passthrough_cmd

bt_status_t bt_avrcp_control_send_passthrough_cmd(bt_instance_t* ins, bt_address_t* addr, uint8_t cmd, uint8_t state);

Send a passthrough command to the remote device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.
• cmd Command code.
• state Key state.

bt_avrcp_control_get_unit_info

bt_status_t bt_avrcp_control_get_unit_info(bt_instance_t* ins, bt_address_t* addr);

Get unit information from the remote AVRCP device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.

bt_avrcp_control_get_subunit_info

bt_status_t bt_avrcp_control_get_subunit_info(bt_instance_t* ins, bt_address_t* addr);

Get subunit information from the remote device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.

bt_avrcp_control_get_playback_state

bt_status_t bt_avrcp_control_get_playback_state(bt_instance_t* ins, bt_address_t* addr);

Get the current playback state of the remote device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.

bt_avrcp_control_register_notification

bt_status_t bt_avrcp_control_register_notification(bt_instance_t* ins, bt_address_t* addr, uint8_t event, uint32_t interval);

Register for event notifications from the remote device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.
• event Event type.
• interval Notification interval.

bt_avrcp_target_unregister_callbacks

bool bt_avrcp_target_unregister_callbacks(bt_instance_t* ins, void* cookie);

Unregister callback functions and stop receiving state change notifications.

Parameters:

• ins Bluetooth client instance.
• cookie User context.

Returns:

Returns the callback cookie on success, or NULL on failure.

bt_avrcp_target_get_play_status_response

bt_status_t bt_avrcp_target_get_play_status_response(bt_instance_t* ins, bt_address_t* addr, avrcp_play_status_t status, uint32_t song_len, uint32_t song_pos);

Respond to a play status query from the remote device.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the peer device.
• status Play status code.
• song_len Song length in milliseconds.
• song_pos Current playback position in milliseconds.

Returns:

Returns BT_STATUS_SUCCESS on success, or an error code on failure.

bt_avrcp_target_play_status_notify

bt_status_t bt_avrcp_target_play_status_notify(bt_instance_t* ins, bt_address_t* addr, avrcp_play_status_t status);

Notify the remote device of a playback status change.

Parameters:

• ins Bluetooth client instance.
• addr Bluetooth address of the remote device.
• status Play status code.

Returns:

Returns BT_STATUS_SUCCESS on success, or an error code on failure.