GATT Client#

sl_bt_gatt_att_opcode_t#

sl_bt_gatt_att_opcode_t

These values indicate which attribute request or response has caused the event.

sl_bt_gatt_client_config_flag_t#

sl_bt_gatt_client_config_flag_t

These values define whether the client is to receive notifications or indications from a remote GATT server.

sl_bt_gatt_execute_write_flag_t#

sl_bt_gatt_execute_write_flag_t

These values define whether the GATT server is to cancel all queued writes or commit all queued writes to a remote database.

sl_bt_gatt_set_max_mtu#

sl_status_t sl_bt_gatt_set_max_mtu (uint16_t max_mtu, uint16_t *max_mtu_out)

Set the maximum size of ATT Message Transfer Units (MTU). Functionality is the same as sl_bt_gatt_server_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 has been established.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_discover_primary_services#

sl_status_t sl_bt_gatt_discover_primary_services (uint8_t connection)

Discover all primary services of a remote GATT database. This command generates a unique gatt_service event for every discovered primary service. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure has successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_service - Discovered service from remote GATT database

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_discover_primary_services_by_uuid#

sl_status_t sl_bt_gatt_discover_primary_services_by_uuid (uint8_t connection, size_t uuid_len, const uint8_t *uuid)

Discover primary services with the specified UUID in a remote GATT database. This command generates unique gatt_service event for every discovered primary service. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure was successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_service - Discovered service from remote GATT database.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_find_included_services#

sl_status_t sl_bt_gatt_find_included_services (uint8_t connection, uint32_t service)

Find the services that are included by a service in a remote GATT database. This command generates a unique gatt_service event for each included service. The received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure was successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_service - Discovered service from remote GATT database.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_discover_characteristics#

sl_status_t sl_bt_gatt_discover_characteristics (uint8_t connection, uint32_t service)

Discover all characteristics of a GATT service from a remote GATT database. This command generates a unique gatt_characteristic event for every discovered characteristic. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure was successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_characteristic - Discovered characteristic from remote GATT database.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_discover_characteristics_by_uuid#

sl_status_t sl_bt_gatt_discover_characteristics_by_uuid (uint8_t connection, uint32_t service, size_t uuid_len, const uint8_t *uuid)

Discover all characteristics of a GATT service in a remote GATT database having the specified UUID. This command generates a unique gatt_characteristic event for every discovered characteristic having the specified UUID. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure was successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_characteristic - Discovered characteristic from remote GATT database.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_discover_descriptors#

sl_status_t sl_bt_gatt_discover_descriptors (uint8_t connection, uint16_t characteristic)

Discover all descriptors in a remote GATT database starting from handle. It generates a unique gatt_descriptor event for every discovered descriptor. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure has successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_descriptor - Discovered descriptor from remote GATT database.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_discover_characteristic_descriptors#

sl_status_t sl_bt_gatt_discover_characteristic_descriptors (uint8_t connection, uint16_t start, uint16_t end)

Discover all descriptors of a GATT characteristic in a remote GATT database. It generates a unique gatt_descriptor event for every discovered descriptor. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure has successfully completed or failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_descriptor - Discovered descriptor from remote GATT database.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_set_characteristic_notification#

sl_status_t sl_bt_gatt_set_characteristic_notification (uint8_t connection, uint16_t characteristic, uint8_t flags)

Enable or disable the notifications and indications sent from a remote GATT server. This procedure discovers a characteristic client configuration descriptor and writes the related configuration flags to a remote GATT database. A received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure was successfully completed or that it failed with an error.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

• sl_bt_evt_gatt_characteristic_value - If an indication or notification has been enabled for a characteristic, this event is triggered whenever an indication or notification is sent by the remote GATT server. The triggering conditions of the GATT server are defined by an upper level, for example by a profile. As a result, it is possible that no values are ever received, or that it may take time, depending on how the server is configured.

sl_bt_gatt_send_characteristic_confirmation#

sl_status_t sl_bt_gatt_send_characteristic_confirmation (uint8_t connection)

Send a confirmation to a remote GATT server after receiving a characteristic indication. The sl_bt_evt_gatt_characteristic_value event carries the att_opcode containing sl_bt_gatt_handle_value_indication (0x1d), which reveals that an indication has been received and must be confirmed with this command. The confirmation needs to be sent within 30 seconds, otherwise further GATT transactions are not allowed by the remote side.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_read_characteristic_value#

sl_status_t sl_bt_gatt_read_characteristic_value (uint8_t connection, uint16_t characteristic)

Read the value of a characteristic from a remote GATT database. A single sl_bt_evt_gatt_characteristic_value is generated if the characteristic value fits in one ATT PDU. Otherwise, more than one sl_bt_evt_gatt_characteristic_value event is generated because the firmware will automatically use the Read Long Characteristic Values procedure. A received sl_bt_evt_gatt_procedure_completed event indicates that all data was read successfully or that an error response was received.

Note that the GATT client does not verify if the requested attribute is a characteristic value. Therefore, before calling this command, ensure that the attribute handle is for a characteristic value, for example, by performing characteristic discovery.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_characteristic_value - Contains the data of a characteristic sent by the GATT Server.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_read_characteristic_value_from_offset#

sl_status_t sl_bt_gatt_read_characteristic_value_from_offset (uint8_t connection, uint16_t characteristic, uint16_t offset, uint16_t maxlen)

Read a partial characteristic value with a specified offset and maximum length from a remote GATT database. It is equivalent to sl_bt_gatt_read_characteristic_value if both the offset and maximum length parameters are 0. A single sl_bt_evt_gatt_characteristic_value event is generated if the value to read fits in one ATT PDU. Otherwise, more than one sl_bt_evt_gatt_characteristic_value events are generated because the firmware will automatically use the Read Long Characteristic Values procedure. A received sl_bt_evt_gatt_procedure_completed event indicates that all data was read successfully or that an error response was received.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_characteristic_value - Contains data of a characteristic sent by the GATT Server.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_read_multiple_characteristic_values#

sl_status_t sl_bt_gatt_read_multiple_characteristic_values (uint8_t connection, size_t characteristic_list_len, const uint8_t *characteristic_list)

Read values of multiple characteristics from a remote GATT database at once. The GATT server returns values in one ATT PDU as the response. If the total set of values is greater than (ATT_MTU - 1) bytes in length, only the first (ATT_MTU - 1) bytes are included. A single sl_bt_evt_gatt_characteristic_value event is generated, in which the characteristic is set to 0 and data in the value parameter is a concatenation of characteristic values in the order they were requested. The received sl_bt_evt_gatt_procedure_completed event indicates either that this GATT procedure was successfully completed or failed with an error.

Use this command only for characteristics values that have a known fixed size, except the last one that could have variable length.

When the remote GATT server is from Silicon Labs Bluetooth stack, the server returns ATT Invalid PDU (0x04) if this command only reads one characteristic value. The server returns ATT Application Error 0x80 if this command reads the value of a user-type characteristic.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_characteristic_value - A concatenation of characteristic values in the order they were requested

• sl_bt_evt_gatt_procedure_completed - Procedure was either successfully completed or failed with an error.

sl_bt_gatt_read_characteristic_value_by_uuid#

sl_status_t sl_bt_gatt_read_characteristic_value_by_uuid (uint8_t connection, uint32_t service, size_t uuid_len, const uint8_t *uuid)

Read characteristic values of a service from a remote GATT database by giving the UUID of the characteristic and the handle of the service containing this characteristic. If multiple characteristic values are received in one ATT PDU, one sl_bt_evt_gatt_characteristic_value event is generated for each value. If the first characteristic value does not fit in one ATT PDU, the firmware automatically uses the Read Long Characteristic Values procedure and generate more sl_bt_evt_gatt_characteristic_value events until the value has been completely read. A received sl_bt_evt_gatt_procedure_completed event indicates that all data was read successfully or that an error response was received.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_characteristic_value - Contains the data of a characteristic sent by the GATT Server.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_write_characteristic_value#

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

Write the value of a characteristic in a remote GATT database. If the value length is greater than (ATT_MTU - 3) and does not fit in one ATT PDU, "write long" GATT procedure is used automatically. Received sl_bt_evt_gatt_procedure_completed event indicates that all data was written successfully or that an error response was received.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_write_characteristic_value_without_response#

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

Write the value of a characteristic in a remote GATT server. It does not generate an event. All failures on the server are ignored silently. For example, if an error is generated in the remote GATT server and the given value is not written into the database, no error message will be reported to the local GATT client. Note that this command can't be used to write long values. At most ATT_MTU - 3 number of bytes can be sent once.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

sl_bt_gatt_prepare_characteristic_value_write#

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

Add a characteristic value to the write queue of a remote GATT server. It can be used when long attributes need to be written or a set of values needs to be written atomically. At most ATT_MTU - 5 number of bytes can be sent at one time. Writes are executed or canceled with the sl_bt_gatt_execute_characteristic_value_write command. Whether the writes succeed or not is indicated in the response of the sl_bt_gatt_execute_characteristic_value_write command.

In all use cases where the amount of data to transfer fits into the BGAPI payload, use the command sl_bt_gatt_write_characteristic_value to write long values because it transparently performs the prepare_write and execute_write commands.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_prepare_characteristic_value_reliable_write#

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

Add a characteristic value to the write queue of a remote GATT server and verify whether the value was correctly received by the server. Received sl_bt_evt_gatt_procedure_completed event indicates that this GATT procedure was successfully completed or failed with an error. Specifically, error code 0x0194 (data_corrupted) will be returned if the value received from the GATT server's response fails to pass the reliable write verification. At most, ATT_MTU - 5 number of bytes can be sent at one time. Writes are executed or canceled with the sl_bt_gatt_execute_characteristic_value_write command. Whether the writes succeed or not is indicated in the response of the sl_bt_gatt_execute_characteristic_value_write command.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_execute_characteristic_value_write#

sl_status_t sl_bt_gatt_execute_characteristic_value_write (uint8_t connection, uint8_t flags)

Commit or cancel previously queued writes to a long characteristic of a remote GATT server. Writes are sent to the queue with sl_bt_gatt_prepare_characteristic_value_write command. Content, offset, and length of queued values are validated by this procedure. A received sl_bt_evt_gatt_procedure_completed event indicates that all data was written successfully or that an error response was received.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_read_descriptor_value#

sl_status_t sl_bt_gatt_read_descriptor_value (uint8_t connection, uint16_t descriptor)

Read the descriptor value of a characteristic in a remote GATT database. A single sl_bt_evt_gatt_descriptor_value event is generated if the descriptor value fits in one ATT PDU. Otherwise, more than one sl_bt_evt_gatt_descriptor_value events are generated because the firmware automatically uses the Read Long Characteristic Values procedure. A received sl_bt_evt_gatt_procedure_completed event indicates that all data was read successfully or that an error response was received.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_descriptor_value - Descriptor value received from the remote GATT server.

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_gatt_write_descriptor_value#

sl_status_t sl_bt_gatt_write_descriptor_value (uint8_t connection, uint16_t descriptor, size_t value_len, const uint8_t *value)

Write the value of a characteristic descriptor in a remote GATT database. If the value length is greater than ATT_MTU - 3 and does not fit in one ATT PDU, "write long" GATT procedure is used automatically. Received sl_bt_evt_gatt_procedure_completed event indicates either that all data was written successfully or that an error response was received.

Returns

• SL_STATUS_OK if successful. Error code otherwise.

Events

• sl_bt_evt_gatt_procedure_completed - Procedure was successfully completed or failed with an error.

sl_bt_cmd_gatt_set_max_mtu_id#

#define sl_bt_cmd_gatt_set_max_mtu_id

0x00090020

sl_bt_cmd_gatt_discover_primary_services_id#

#define sl_bt_cmd_gatt_discover_primary_services_id

0x01090020

sl_bt_cmd_gatt_discover_primary_services_by_uuid_id#

#define sl_bt_cmd_gatt_discover_primary_services_by_uuid_id

0x02090020

sl_bt_cmd_gatt_find_included_services_id#

#define sl_bt_cmd_gatt_find_included_services_id

0x10090020

sl_bt_cmd_gatt_discover_characteristics_id#

#define sl_bt_cmd_gatt_discover_characteristics_id

0x03090020

sl_bt_cmd_gatt_discover_characteristics_by_uuid_id#

#define sl_bt_cmd_gatt_discover_characteristics_by_uuid_id

0x04090020

sl_bt_cmd_gatt_discover_descriptors_id#

#define sl_bt_cmd_gatt_discover_descriptors_id

0x06090020

sl_bt_cmd_gatt_discover_characteristic_descriptors_id#

#define sl_bt_cmd_gatt_discover_characteristic_descriptors_id

0x14090020

sl_bt_cmd_gatt_set_characteristic_notification_id#

#define sl_bt_cmd_gatt_set_characteristic_notification_id

0x05090020

sl_bt_cmd_gatt_send_characteristic_confirmation_id#

#define sl_bt_cmd_gatt_send_characteristic_confirmation_id

0x0d090020

sl_bt_cmd_gatt_read_characteristic_value_id#

#define sl_bt_cmd_gatt_read_characteristic_value_id

0x07090020

sl_bt_cmd_gatt_read_characteristic_value_from_offset_id#

#define sl_bt_cmd_gatt_read_characteristic_value_from_offset_id

0x12090020

sl_bt_cmd_gatt_read_multiple_characteristic_values_id#

#define sl_bt_cmd_gatt_read_multiple_characteristic_values_id

0x11090020

sl_bt_cmd_gatt_read_characteristic_value_by_uuid_id#

#define sl_bt_cmd_gatt_read_characteristic_value_by_uuid_id

0x08090020

sl_bt_cmd_gatt_write_characteristic_value_id#

#define sl_bt_cmd_gatt_write_characteristic_value_id

0x09090020

sl_bt_cmd_gatt_write_characteristic_value_without_response_id#

#define sl_bt_cmd_gatt_write_characteristic_value_without_response_id

0x0a090020

sl_bt_cmd_gatt_prepare_characteristic_value_write_id#

#define sl_bt_cmd_gatt_prepare_characteristic_value_write_id

0x0b090020

sl_bt_cmd_gatt_prepare_characteristic_value_reliable_write_id#

#define sl_bt_cmd_gatt_prepare_characteristic_value_reliable_write_id

0x13090020

sl_bt_cmd_gatt_execute_characteristic_value_write_id#

#define sl_bt_cmd_gatt_execute_characteristic_value_write_id

0x0c090020

sl_bt_cmd_gatt_read_descriptor_value_id#

#define sl_bt_cmd_gatt_read_descriptor_value_id

0x0e090020

sl_bt_cmd_gatt_write_descriptor_value_id#

#define sl_bt_cmd_gatt_write_descriptor_value_id

0x0f090020

sl_bt_rsp_gatt_set_max_mtu_id#

#define sl_bt_rsp_gatt_set_max_mtu_id

0x00090020

sl_bt_rsp_gatt_discover_primary_services_id#

#define sl_bt_rsp_gatt_discover_primary_services_id

0x01090020

sl_bt_rsp_gatt_discover_primary_services_by_uuid_id#

#define sl_bt_rsp_gatt_discover_primary_services_by_uuid_id

0x02090020

sl_bt_rsp_gatt_find_included_services_id#

#define sl_bt_rsp_gatt_find_included_services_id

0x10090020

sl_bt_rsp_gatt_discover_characteristics_id#

#define sl_bt_rsp_gatt_discover_characteristics_id

0x03090020

sl_bt_rsp_gatt_discover_characteristics_by_uuid_id#

#define sl_bt_rsp_gatt_discover_characteristics_by_uuid_id

0x04090020

sl_bt_rsp_gatt_discover_descriptors_id#

#define sl_bt_rsp_gatt_discover_descriptors_id

0x06090020

sl_bt_rsp_gatt_discover_characteristic_descriptors_id#

#define sl_bt_rsp_gatt_discover_characteristic_descriptors_id

0x14090020

sl_bt_rsp_gatt_set_characteristic_notification_id#

#define sl_bt_rsp_gatt_set_characteristic_notification_id

0x05090020

sl_bt_rsp_gatt_send_characteristic_confirmation_id#

#define sl_bt_rsp_gatt_send_characteristic_confirmation_id

0x0d090020

sl_bt_rsp_gatt_read_characteristic_value_id#

#define sl_bt_rsp_gatt_read_characteristic_value_id

0x07090020

sl_bt_rsp_gatt_read_characteristic_value_from_offset_id#

#define sl_bt_rsp_gatt_read_characteristic_value_from_offset_id

0x12090020

sl_bt_rsp_gatt_read_multiple_characteristic_values_id#

#define sl_bt_rsp_gatt_read_multiple_characteristic_values_id

0x11090020

sl_bt_rsp_gatt_read_characteristic_value_by_uuid_id#

#define sl_bt_rsp_gatt_read_characteristic_value_by_uuid_id

0x08090020

sl_bt_rsp_gatt_write_characteristic_value_id#

#define sl_bt_rsp_gatt_write_characteristic_value_id

0x09090020

sl_bt_rsp_gatt_write_characteristic_value_without_response_id#

#define sl_bt_rsp_gatt_write_characteristic_value_without_response_id

0x0a090020

sl_bt_rsp_gatt_prepare_characteristic_value_write_id#

#define sl_bt_rsp_gatt_prepare_characteristic_value_write_id

0x0b090020

sl_bt_rsp_gatt_prepare_characteristic_value_reliable_write_id#

#define sl_bt_rsp_gatt_prepare_characteristic_value_reliable_write_id

0x13090020

sl_bt_rsp_gatt_execute_characteristic_value_write_id#

#define sl_bt_rsp_gatt_execute_characteristic_value_write_id

0x0c090020

sl_bt_rsp_gatt_read_descriptor_value_id#

#define sl_bt_rsp_gatt_read_descriptor_value_id

0x0e090020

sl_bt_rsp_gatt_write_descriptor_value_id#

#define sl_bt_rsp_gatt_write_descriptor_value_id

0x0f090020