GATT Server#

GATT Server.

Modules#

sl_bt_evt_gatt_server_attribute_value

sl_bt_evt_gatt_server_user_read_request

sl_bt_evt_gatt_server_user_write_request

sl_bt_evt_gatt_server_characteristic_status

sl_bt_evt_gatt_server_execute_write_completed

Enumerations#

Functions#

Detailed Description#

GATT Server.

These commands and events are used by the local GATT server to manage the local GATT database.

Enumeration Type Documentation#

gatt_server_characteristic_status_flag_t#

enum gatt_server_characteristic_status_flag_t

Characteristic Status Flag.

Function Documentation#

sl_bt_gatt_server_set_capabilities()#

(
	 uint32_t 	 caps, 
	 uint32_t 	 reserved 
)

Reset capabilities that should be enabled by the GATT database. A service is visible to remote GATT clients if at least one of its capabilities is enabled. The same applies to a characteristic and its attributes. Capability identifiers and their corresponding bit flag values can be found in the auto-generated database header file. See UG118: Blue Gecko Bluetooth Profile Toolkit Developer's Guide for how to declare capabilities in the GATT database.

Changing the capabilities of a database effectively causes a database change (attributes being added or removed) from a remote GATT client point of view. If the database has a Generic Attribute service and Service Changed characteristic, the stack will monitor the local database change status and manage service changed indications for a GATT client that has enabled the indication configuration of the Service Changed characteristic.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_enable_capabilities()#

(
	 uint32_t 	 caps 
)

Enable additional capabilities in the local GATT database. Already enabled capabilities keep unchanged after this command. See sl_bt_gatt_server_set_capabilities for more information.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_disable_capabilities()#

(
	 uint32_t 	 caps 
)

Disable the given capabilities in the local GATT database. See sl_bt_gatt_server_set_capabilities for more information.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_get_enabled_capabilities()#

(
	 uint32_t * 	 caps 
)

Get capabilities currently enabled in the local GATT database.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_set_max_mtu()#

(
	 uint16_t 	 max_mtu, 
	 uint16_t * 	 max_mtu_out 
)

Set the maximum size of ATT Message Transfer Units (MTU). The functionality is the same as sl_bt_gatt_set_max_mtu and this setting applies to both GATT client and server. If the given value is too large according to the maximum BGAPI payload size, the system will select the maximum possible value as the maximum ATT_MTU. If the maximum ATT_MTU is larger than 23, the GATT client in the stack will automatically send an MTU exchange request after a Bluetooth connection was established.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_get_mtu()#

(
	 uint8_t 		connection, 
	 uint16_t * 	mtu  
)

Get the size of ATT Message Transfer Units (MTU) for a connection.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_find_attribute()#

(
	 uint16_t 	 start, 
	 size_t 	 type_len, 
	 const uint8_t *  	 type, 
	 uint16_t *  	 attribute
)

Find attributes of a certain type from a local GATT database. The type is usually given as a 16-bit or 128-bit UUID in little endian format.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_read_attribute_value()#

(
	 uint16_t 	 attribute, 
	 uint16_t  	 offset, 
	 size_t  	 max_value_size, 
	 size_t *  	 value_len, 
	 uint8_t *  	 value 
)

Read the value of an attribute from a local GATT database. Only (maximum BGAPI payload size - 3) amount of data can be read at once. The application can continue reading with increased offset value if it receives (maximum BGAPI payload size - 3) amount of data.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_read_attribute_type()#

(
	 uint16_t  	 attribute, 
	 size_t  	 max_type_size, 
	 size_t *  	 type_len, 
	 uint8_t *  	 type 
)

Read the type of an attribute from a local GATT database. The type is a UUID, usually 16 or 128 bits long in little endian format.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_write_attribute_value()#

(
	 uint16_t  	 attribute, 
	 uint16_t  	 offset, 
	 size_t  	 value_len, 
	 const uint8_t *  	 value 
)

Write the value of an attribute in the local GATT database. Writing the value of a characteristic of the local GATT database will not trigger notifications or indications to the remote GATT client if the characteristic has a property to indicate or notify and the client has enabled notification or indication. Notifications and indications are sent to the remote GATT client using sl_bt_gatt_server_send_characteristic_notification command.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_send_user_read_response()#

(
	 uint8_t 	 connection, 
	 uint16_t  	 characteristic, 
	 uint8_t  	 att_errorcode, 
	 size_t  	 value_len, 
	 const uint8_t *  	 value, 
	 uint16_t *  	 sent_len 
)

Send a response to a sl_bt_evt_gatt_server_user_read_request event. The response needs to be sent within 30 seconds, otherwise no more GATT transactions are allowed by the remote side. If attr_errorcode is set to 0, the characteristic value is sent to the remote GATT client in the standard way. Other attr_errorcode values will cause the local GATT server to send an attribute protocol error response instead of the actual data. At most ATT_MTU - 1 amount of data can be sent at one time. The client will continue reading by sending new read request with an increased offset value if it receives ATT_MTU - 1 amount of data.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_send_user_write_response()#

(
	 uint8_t  	 connection, 
	 uint16_t  	 characteristic, 
	 uint8_t  	 att_errorcode` 
)

Send a response to a sl_bt_evt_gatt_server_user_write_request event when parameter att_opcode in the event is gatt_write_request (see gatt_att_opcode). The response needs to be sent within 30 seconds, otherwise no more GATT transactions are allowed by the remote side. If attr_errorcode is set to 0, the ATT protocol's write response is sent to indicate to the remote GATT client that the write operation was processed successfully. Other values will cause the local GATT server to send an ATT protocol error response.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_server_send_characteristic_notification()#

(
	 uint8_t  	 connection, 
	 uint16_t  	 characteristic, 
	 size_t  	 value_len, 
	 const uint8_t *  	 value, 
	 uint16_t *  	 sent_len 
)

Send notifications or indications to one or more remote GATT clients. At most ATT_MTU - 3 amount of data can be sent one time.

A notification or indication is sent only if the client has enabled it by setting the corresponding flag to the Client Characteristic Configuration descriptor. If the Client Characteristic Configuration descriptor supports both notifications and indications, the stack will always send a notification even when the client has enabled both.

A new indication to a GATT client can't be sent until an outstanding indication procedure with the same client has completed. The procedure is completed when a confirmation from the client is received. The confirmation is indicated by sl_bt_evt_gatt_server_characteristic_status.

Error bg_err_wrong_state is returned if the characteristic does not have the notification property, or if the client has not enabled the notification. The same applies to the indication property, and in addition, bg_err_wrong_state is returned if an indication procedure with the same client is outstanding. Always check the response for this command for errors before trying to send more data.

Parameters

Returns

 SL_STATUS_OK if successful. Error code otherwise.