Volume Control Profile (VCP) More...

Data Structures
struct	bt_vcp_vol_rend_register_param
	Register structure for Volume Control Service. More...

struct	bt_vcp_included
	Volume Control Service included services. More...

struct	bt_vcp_vol_rend_cb
	Struct to hold the Volume Renderer callbacks. More...

struct	bt_vcp_vol_ctlr_cb
	Struct to hold the Volume Controller callbacks. More...

Macros
#define	BT_VCP_VOL_REND_VOCS_CNT 0
	Defines the maximum number of Volume Offset Control service instances for the Volume Control Profile Volume Renderer.

#define	BT_VCP_VOL_REND_AICS_CNT 0
	Defines the maximum number of Audio Input Control service instances for the Volume Control Profile Volume Renderer.

Functions
int	bt_vcp_vol_rend_included_get (struct bt_vcp_included *included)
	Get Volume Control Service included services.

int	bt_vcp_vol_rend_register (struct bt_vcp_vol_rend_register_param *param)
	Register the Volume Control Service.

int	bt_vcp_vol_rend_set_step (uint8_t volume_step)
	Set the Volume Control Service volume step size.

int	bt_vcp_vol_rend_get_state (void)
	Get the Volume Control Service volume state.

int	bt_vcp_vol_rend_get_flags (void)
	Get the Volume Control Service flags.

int	bt_vcp_vol_rend_vol_down (void)
	Turn the volume down by one step on the server.

int	bt_vcp_vol_rend_vol_up (void)
	Turn the volume up by one step on the server.

int	bt_vcp_vol_rend_unmute_vol_down (void)
	Turn the volume down and unmute the server.

int	bt_vcp_vol_rend_unmute_vol_up (void)
	Turn the volume up and unmute the server.

int	bt_vcp_vol_rend_set_vol (uint8_t volume)
	Set the volume on the server.

int	bt_vcp_vol_rend_unmute (void)
	Unmute the server.

int	bt_vcp_vol_rend_mute (void)
	Mute the server.

int	bt_vcp_vol_ctlr_cb_register (struct bt_vcp_vol_ctlr_cb *cb)
	Registers the callbacks used by the Volume Controller.

int	bt_vcp_vol_ctlr_cb_unregister (struct bt_vcp_vol_ctlr_cb *cb)
	Unregisters the callbacks used by the Volume Controller.

int	bt_vcp_vol_ctlr_discover (struct bt_conn conn, struct bt_vcp_vol_ctlr *vol_ctlr)
	Discover Volume Control Service and included services.

struct bt_vcp_vol_ctlr *	bt_vcp_vol_ctlr_get_by_conn (const struct bt_conn *conn)
	Get the volume controller from a connection pointer.

int	bt_vcp_vol_ctlr_conn_get (const struct bt_vcp_vol_ctlr vol_ctlr, struct bt_conn *conn)
	Get the connection pointer of a client instance.

int	bt_vcp_vol_ctlr_included_get (struct bt_vcp_vol_ctlr vol_ctlr, struct bt_vcp_included included)
	Get Volume Control Service included services.

int	bt_vcp_vol_ctlr_read_state (struct bt_vcp_vol_ctlr *vol_ctlr)
	Read the volume state of a remote Volume Renderer.

int	bt_vcp_vol_ctlr_read_flags (struct bt_vcp_vol_ctlr *vol_ctlr)
	Read the volume flags of a remote Volume Renderer.

int	bt_vcp_vol_ctlr_vol_down (struct bt_vcp_vol_ctlr *vol_ctlr)
	Turn the volume down one step on a remote Volume Renderer.

int	bt_vcp_vol_ctlr_vol_up (struct bt_vcp_vol_ctlr *vol_ctlr)
	Turn the volume up one step on a remote Volume Renderer.

int	bt_vcp_vol_ctlr_unmute_vol_down (struct bt_vcp_vol_ctlr *vol_ctlr)
	Turn the volume down one step and unmute on a remote Volume Renderer.

int	bt_vcp_vol_ctlr_unmute_vol_up (struct bt_vcp_vol_ctlr *vol_ctlr)
	Turn the volume up one step and unmute on a remote Volume Renderer.

int	bt_vcp_vol_ctlr_set_vol (struct bt_vcp_vol_ctlr *vol_ctlr, uint8_t volume)
	Set the absolute volume on a remote Volume Renderer.

int	bt_vcp_vol_ctlr_unmute (struct bt_vcp_vol_ctlr *vol_ctlr)
	Unmute a remote Volume Renderer.

int	bt_vcp_vol_ctlr_mute (struct bt_vcp_vol_ctlr *vol_ctlr)
	Mute a remote Volume Renderer.

Volume Control Service Error codes
#define	BT_VCP_ERR_INVALID_COUNTER 0x80
	The Change_Counter operand value does not match the Change_Counter field value of the Volume State characteristic.

#define	BT_VCP_ERR_OP_NOT_SUPPORTED 0x81
	An invalid opcode has been used in a control point procedure.

Volume Control Service Mute Values
#define	BT_VCP_STATE_UNMUTED 0x00
	The volume state is unmuted.

#define	BT_VCP_STATE_MUTED 0x01
	The volume state is muted.

Detailed Description

Volume Control Profile (VCP)

Since: 2.7

Version: 0.8.0

The Volume Control Profile (VCP) provides procedures to control the volume level and mute state on audio devices.

Macro Definition Documentation

◆ BT_VCP_ERR_INVALID_COUNTER

#define BT_VCP_ERR_INVALID_COUNTER 0x80

#include <include/zephyr/bluetooth/audio/vcp.h>

The Change_Counter operand value does not match the Change_Counter field value of the Volume State characteristic.

◆ BT_VCP_ERR_OP_NOT_SUPPORTED

#define BT_VCP_ERR_OP_NOT_SUPPORTED 0x81

#include <include/zephyr/bluetooth/audio/vcp.h>

An invalid opcode has been used in a control point procedure.

◆ BT_VCP_STATE_MUTED

#define BT_VCP_STATE_MUTED 0x01

#include <include/zephyr/bluetooth/audio/vcp.h>

The volume state is muted.

◆ BT_VCP_STATE_UNMUTED

#define BT_VCP_STATE_UNMUTED 0x00

#include <include/zephyr/bluetooth/audio/vcp.h>

The volume state is unmuted.

◆ BT_VCP_VOL_REND_AICS_CNT

#define BT_VCP_VOL_REND_AICS_CNT 0

#include <include/zephyr/bluetooth/audio/vcp.h>

Defines the maximum number of Audio Input Control service instances for the Volume Control Profile Volume Renderer.

◆ BT_VCP_VOL_REND_VOCS_CNT

#define BT_VCP_VOL_REND_VOCS_CNT 0

#include <include/zephyr/bluetooth/audio/vcp.h>

Defines the maximum number of Volume Offset Control service instances for the Volume Control Profile Volume Renderer.

Function Documentation

◆ bt_vcp_vol_ctlr_cb_register()

int bt_vcp_vol_ctlr_cb_register ( struct bt_vcp_vol_ctlr_cb * cb )

#include <include/zephyr/bluetooth/audio/vcp.h>

Registers the callbacks used by the Volume Controller.

Parameters

cb	The callback structure.

Return values

0	on success
-EINVAL	if `cb` is NULL
-EALREADY	if `cb` was already registered

◆ bt_vcp_vol_ctlr_cb_unregister()

int bt_vcp_vol_ctlr_cb_unregister ( struct bt_vcp_vol_ctlr_cb * cb )

#include <include/zephyr/bluetooth/audio/vcp.h>

Unregisters the callbacks used by the Volume Controller.

Parameters

cb	The callback structure.

Return values

0	on success
-EINVAL	if `cb` is NULL
-EALREADY	if `cb` was not registered

◆ bt_vcp_vol_ctlr_conn_get()

int bt_vcp_vol_ctlr_conn_get	(	const struct bt_vcp_vol_ctlr *	vol_ctlr,
		struct bt_conn **	conn
	)

#include <include/zephyr/bluetooth/audio/vcp.h>

Get the connection pointer of a client instance.

Get the Bluetooth connection pointer of a Volume Control Service client instance.

Parameters

	vol_ctlr	Volume Controller instance pointer.
[out]	conn	Connection pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_discover()

int bt_vcp_vol_ctlr_discover	(	struct bt_conn *	conn,
		struct bt_vcp_vol_ctlr **	vol_ctlr
	)

#include <include/zephyr/bluetooth/audio/vcp.h>

Discover Volume Control Service and included services.

This will start a GATT discovery and setup handles and subscriptions. This shall be called once before any other actions can be executed for the peer device, and the bt_vcp_vol_ctlr_cb::discover callback will notify when it is possible to start remote operations.

This shall only be done as the client,

Parameters

	conn	The connection to discover Volume Control Service for.
[out]	vol_ctlr	Valid remote instance object on success.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_get_by_conn()

struct bt_vcp_vol_ctlr * bt_vcp_vol_ctlr_get_by_conn ( const struct bt_conn * conn )

#include <include/zephyr/bluetooth/audio/vcp.h>

Get the volume controller from a connection pointer.

Get the Volume Control Profile Volume Controller pointer from a connection pointer. Only volume controllers that have been initiated via bt_vcp_vol_ctlr_discover() can be retrieved.

Parameters

conn	Connection pointer.

Return values

Pointer	to a Volume Control Profile Volume Controller instance
NULL	if `conn` is NULL or if the connection has not done discovery yet

◆ bt_vcp_vol_ctlr_included_get()

int bt_vcp_vol_ctlr_included_get	(	struct bt_vcp_vol_ctlr *	vol_ctlr,
		struct bt_vcp_included *	included
	)

#include <include/zephyr/bluetooth/audio/vcp.h>

Get Volume Control Service included services.

Returns a pointer to a struct that contains information about the Volume Control Service included service instances, such as pointers to the Volume Offset Control Service (Volume Offset Control Service) or Audio Input Control Service (AICS) instances.

Requires that CONFIG_BT_VCP_VOL_CTLR_VOCS or CONFIG_BT_VCP_VOL_CTLR_AICS is enabled.

Parameters

	vol_ctlr	Volume Controller instance pointer.
[out]	included	Pointer to store the result in.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_mute()

int bt_vcp_vol_ctlr_mute ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Mute a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_read_flags()

int bt_vcp_vol_ctlr_read_flags ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Read the volume flags of a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_read_state()

int bt_vcp_vol_ctlr_read_state ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Read the volume state of a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_set_vol()

int bt_vcp_vol_ctlr_set_vol	(	struct bt_vcp_vol_ctlr *	vol_ctlr,
		uint8_t	volume
	)

#include <include/zephyr/bluetooth/audio/vcp.h>

Set the absolute volume on a remote Volume Renderer.

Parameters

vol_ctlr	Volume Controller instance pointer.
volume	The absolute volume to set.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_unmute()

int bt_vcp_vol_ctlr_unmute ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Unmute a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_unmute_vol_down()

int bt_vcp_vol_ctlr_unmute_vol_down ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume down one step and unmute on a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_unmute_vol_up()

int bt_vcp_vol_ctlr_unmute_vol_up ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume up one step and unmute on a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_vol_down()

int bt_vcp_vol_ctlr_vol_down ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume down one step on a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_ctlr_vol_up()

int bt_vcp_vol_ctlr_vol_up ( struct bt_vcp_vol_ctlr * vol_ctlr )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume up one step on a remote Volume Renderer.

Parameters

vol_ctlr Volume Controller instance pointer.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_get_flags()

int bt_vcp_vol_rend_get_flags ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Get the Volume Control Service flags.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_get_state()

int bt_vcp_vol_rend_get_state ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Get the Volume Control Service volume state.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_included_get()

int bt_vcp_vol_rend_included_get ( struct bt_vcp_included * included )

#include <include/zephyr/bluetooth/audio/vcp.h>

Get Volume Control Service included services.

Returns a pointer to a struct that contains information about the Volume Control Service included service instances, such as pointers to the Volume Offset Control Service (Volume Offset Control Service) or Audio Input Control Service (AICS) instances.

Parameters

[out] included Pointer to store the result in.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_mute()

int bt_vcp_vol_rend_mute ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Mute the server.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_register()

int bt_vcp_vol_rend_register ( struct bt_vcp_vol_rend_register_param * param )

#include <include/zephyr/bluetooth/audio/vcp.h>

Register the Volume Control Service.

This will register and enable the service and make it discoverable by clients.

Parameters

param Volume Control Service register parameters.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_set_step()

int bt_vcp_vol_rend_set_step ( uint8_t volume_step )

#include <include/zephyr/bluetooth/audio/vcp.h>

Set the Volume Control Service volume step size.

Set the value that the volume changes, when changed relatively with e.g. bt_vcp_vol_rend_vol_down or bt_vcp_vol_rend_vol_up.

This can only be done as the server.

Parameters

volume_step The volume step size (1-255).

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_set_vol()

int bt_vcp_vol_rend_set_vol ( uint8_t volume )

#include <include/zephyr/bluetooth/audio/vcp.h>

Set the volume on the server.

Parameters

volume The absolute volume to set.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_unmute()

int bt_vcp_vol_rend_unmute ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Unmute the server.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_unmute_vol_down()

int bt_vcp_vol_rend_unmute_vol_down ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume down and unmute the server.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_unmute_vol_up()

int bt_vcp_vol_rend_unmute_vol_up ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume up and unmute the server.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_vol_down()

int bt_vcp_vol_rend_vol_down ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume down by one step on the server.

Returns: 0 if success, errno on failure.

◆ bt_vcp_vol_rend_vol_up()

int bt_vcp_vol_rend_vol_up ( void )

#include <include/zephyr/bluetooth/audio/vcp.h>

Turn the volume up by one step on the server.

Returns: 0 if success, errno on failure.

Data Structures

Macros

Functions

Volume Control Service Error codes

Volume Control Service Mute Values

Detailed Description

Macro Definition Documentation

◆ BT_VCP_ERR_INVALID_COUNTER

◆ BT_VCP_ERR_OP_NOT_SUPPORTED

◆ BT_VCP_STATE_MUTED

◆ BT_VCP_STATE_UNMUTED

◆ BT_VCP_VOL_REND_AICS_CNT

◆ BT_VCP_VOL_REND_VOCS_CNT

Function Documentation

◆ bt_vcp_vol_ctlr_cb_register()

◆ bt_vcp_vol_ctlr_cb_unregister()

◆ bt_vcp_vol_ctlr_conn_get()

◆ bt_vcp_vol_ctlr_discover()

◆ bt_vcp_vol_ctlr_get_by_conn()

◆ bt_vcp_vol_ctlr_included_get()

◆ bt_vcp_vol_ctlr_mute()

◆ bt_vcp_vol_ctlr_read_flags()

◆ bt_vcp_vol_ctlr_read_state()

◆ bt_vcp_vol_ctlr_set_vol()

◆ bt_vcp_vol_ctlr_unmute()

◆ bt_vcp_vol_ctlr_unmute_vol_down()

◆ bt_vcp_vol_ctlr_unmute_vol_up()

◆ bt_vcp_vol_ctlr_vol_down()

◆ bt_vcp_vol_ctlr_vol_up()

◆ bt_vcp_vol_rend_get_flags()

◆ bt_vcp_vol_rend_get_state()

◆ bt_vcp_vol_rend_included_get()

◆ bt_vcp_vol_rend_mute()

◆ bt_vcp_vol_rend_register()

◆ bt_vcp_vol_rend_set_step()

◆ bt_vcp_vol_rend_set_vol()

◆ bt_vcp_vol_rend_unmute()

◆ bt_vcp_vol_rend_unmute_vol_down()

◆ bt_vcp_vol_rend_unmute_vol_up()

◆ bt_vcp_vol_rend_vol_down()

◆ bt_vcp_vol_rend_vol_up()