Functions

Discovers information about a range of attributes on a GATT server.

Events generated

BLE_GATTC_EVT_ATTR_INFO_DISC_RSP

Generated when information about a range of attributes has been received.

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_handle_range	The range of handles to request information about.

Return values

NRF_SUCCESS	Successfully started an attribute information discovery procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid connection handle.
NRF_ERROR_INVALID_STATE	Invalid connection state
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate or continue a GATT Read using Characteristic UUID procedure.

This function initiates or resumes a Read using Characteristic UUID procedure. If the last Characteristic has not been reached, this must be called again with an updated handle range to continue the discovery.

Events generated

BLE_GATTC_EVT_CHAR_VAL_BY_UUID_READ_RSP

Relevant Message Sequence Charts

GATTC Read Characteristic Value by UUID

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_uuid	Pointer to a Characteristic value UUID to read.
[in]	p_handle_range	A pointer to the range of handles to perform this procedure on.

Return values

NRF_SUCCESS	Successfully started or resumed the Read using Characteristic UUID procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate a GATT Read Multiple Characteristic Values procedure.

This function initiates a GATT Read Multiple Characteristic Values procedure.

Events generated

BLE_GATTC_EVT_CHAR_VALS_READ_RSP

Relevant Message Sequence Charts

GATTC Read Multiple Characteristic Values

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_handles	A pointer to the handle(s) of the attribute(s) to be read.
[in]	handle_count	The number of handles in p_handles.

Return values

NRF_SUCCESS	Successfully started the Read Multiple Characteristic Values procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate or continue a GATT Characteristic Discovery procedure.

This function initiates or resumes a Characteristic discovery procedure. If the last Characteristic has not been reached, this must be called again with an updated handle range to continue the discovery.

Note

If any of the discovered characteristics have 128-bit UUIDs which are not present in the table provided to ble_vs_uuids_assign, a UUID structure with type BLE_UUID_TYPE_UNKNOWN will be received in the corresponding event.

Events generated

BLE_GATTC_EVT_CHAR_DISC_RSP

Relevant Message Sequence Charts

GATTC Characteristic Discovery

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_handle_range	A pointer to the range of handles of the Service to perform this procedure on.

Return values

NRF_SUCCESS	Successfully started or resumed the Characteristic Discovery procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate or continue a GATT Characteristic Descriptor Discovery procedure.

This function initiates or resumes a Characteristic Descriptor discovery procedure. If the last Descriptor has not been reached, this must be called again with an updated handle range to continue the discovery.

Events generated

BLE_GATTC_EVT_DESC_DISC_RSP

Relevant Message Sequence Charts

GATTC Descriptor Discovery

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_handle_range	A pointer to the range of handles of the Characteristic to perform this procedure on.

Return values

NRF_SUCCESS	Successfully started or resumed the Descriptor Discovery procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Iterate through Handle-Value(s) list in BLE_GATTC_EVT_CHAR_VAL_BY_UUID_READ_RSP event.

Parameters

[in]

p_gattc_evt

Pointer to event buffer containing BLE_GATTC_EVT_CHAR_VAL_BY_UUID_READ_RSP event.

Note

If the buffer contains different event, behavior is undefined.

Parameters

[in,out]

p_iter

Iterator, points to ble_gattc_handle_value_t structure that will be filled in with the next Handle-Value pair in each iteration. If the function returns other than NRF_SUCCESS , it will not be changed. To start iteration, initialize the structure to zero. To continue, pass the value from previous iteration.

Return values

NRF_SUCCESS	Successfully retrieved the next Handle-Value pair.
NRF_ERROR_NOT_FOUND	No more Handle-Value pairs available in the list.

Start an ATT_MTU exchange by sending an Exchange MTU Request to the server.

The SoftDevice sets ATT_MTU to the minimum of:

• The Client RX MTU value, and
• The Server RX MTU value from BLE_GATTC_EVT_EXCHANGE_MTU_RSP .

However, the SoftDevice never sets ATT_MTU lower than BLE_GATT_ATT_MTU_DEFAULT .

Events generated

BLE_GATTC_EVT_EXCHANGE_MTU_RSP

Relevant Message Sequence Charts

GATTC ATT_MTU Exchange

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	client_rx_mtu	Client RX MTU size. The minimum value is BLE_GATT_ATT_MTU_DEFAULT . The maximum value is ble_gatt_conn_cfg_t::att_mtu in the connection configuration used for this connection. The value must be equal to Server RX MTU size given in sd_ble_gatts_exchange_mtu_reply if an ATT_MTU exchange has already been performed in the other direction.

Return values

NRF_SUCCESS	Successfully sent request to the server.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid connection handle.
NRF_ERROR_INVALID_STATE	Invalid connection state or an ATT_MTU exchange was already requested once.
NRF_ERROR_INVALID_PARAM	Invalid Client RX MTU size supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Send a Handle Value Confirmation to the GATT Server.

Relevant Message Sequence Charts

GATTC Handle Value Indication

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	handle	The handle of the attribute in the indication.

Return values

NRF_SUCCESS	Successfully queued the Handle Value Confirmation for transmission.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State or no Indication pending to be confirmed.
BLE_ERROR_INVALID_ATTR_HANDLE	Invalid attribute handle.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate or continue a GATT Primary Service Discovery procedure.

This function initiates or resumes a Primary Service discovery procedure, starting from the supplied handle. If the last service has not been reached, this function must be called again with an updated start handle value to continue the search.

Note

If any of the discovered services have 128-bit UUIDs which are not present in the table provided to ble_vs_uuids_assign, a UUID structure with type BLE_UUID_TYPE_UNKNOWN will be received in the corresponding event.

Events generated

BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP

Relevant Message Sequence Charts

GATTC Primary Service Discovery

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	start_handle	Handle to start searching from.
[in]	p_srvc_uuid	Pointer to the service UUID to be found. If it is NULL, all primary services will be returned.

Return values

NRF_SUCCESS	Successfully started or resumed the Primary Service Discovery procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_PARAM	Invalid parameter(s) supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate or continue a GATT Read (Long) Characteristic or Descriptor procedure.

This function initiates or resumes a GATT Read (Long) Characteristic or Descriptor procedure. If the Characteristic or Descriptor to be read is longer than ATT_MTU - 1, this function must be called multiple times with appropriate offset to read the complete value.

Events generated

BLE_GATTC_EVT_READ_RSP

Relevant Message Sequence Charts

GATTC Characteristic or Descriptor Value Read

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	handle	The handle of the attribute to be read.
[in]	offset	Offset into the attribute value to be read.

Return values

NRF_SUCCESS	Successfully started or resumed the Read (Long) procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Initiate or continue a GATT Relationship Discovery procedure.

This function initiates or resumes the Find Included Services sub-procedure. If the last included service has not been reached, this must be called again with an updated handle range to continue the search.

Events generated

BLE_GATTC_EVT_REL_DISC_RSP

Relevant Message Sequence Charts

GATTC Relationship Discovery

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_handle_range	A pointer to the range of handles of the Service to perform this procedure on.

Return values

NRF_SUCCESS	Successfully started or resumed the Relationship Discovery procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_INVALID_PARAM	Invalid parameter(s) supplied.
NRF_ERROR_BUSY	Client procedure already in progress.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.

Perform a Write (Characteristic Value or Descriptor, with or without response, signed or not, long or reliable) procedure.

This function can perform all write procedures described in GATT.

Note

Only one write with response procedure can be ongoing per connection at a time. If the application tries to write with response while another write with response procedure is ongoing, the function call will return NRF_ERROR_BUSY . A BLE_GATTC_EVT_WRITE_RSP event will be issued as soon as the write response arrives from the peer.

The number of Write without Response that can be queued is configured by ble_gattc_conn_cfg_t::write_cmd_tx_queue_size When the queue is full, the function call will return NRF_ERROR_RESOURCES . A BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE event will be issued as soon as the transmission of the write without response is complete.

The application can keep track of the available queue element count for writes without responses by following the procedure below:

• Store initial queue element count in a variable.
• Decrement the variable, which stores the currently available queue element count, by one when a call to this function returns NRF_SUCCESS .
• Increment the variable, which stores the current available queue element count, by the count variable in BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE event.

Events generated

BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE	Write without response transmission complete.
BLE_GATTC_EVT_WRITE_RSP	Write response received from the peer.

Relevant Message Sequence Charts

GATTC Characteristic Value Write Without Response

GATTC Characteristic or Descriptor Value Write

GATTC Characteristic or Descriptor Value Long Write

GATTC Characteristic or Descriptor Value Reliable Write

Parameters

[in]	conn_handle	The connection handle identifying the connection to perform this procedure on.
[in]	p_write_params	A pointer to a write parameters structure.

Return values

NRF_SUCCESS	Successfully started the Write procedure.
BLE_ERROR_INVALID_CONN_HANDLE	Invalid Connection Handle.
NRF_ERROR_INVALID_STATE	Invalid Connection State.
NRF_ERROR_INVALID_ADDR	Invalid pointer supplied.
NRF_ERROR_INVALID_PARAM	Invalid parameter(s) supplied.
NRF_ERROR_DATA_SIZE	Invalid data size(s) supplied.
NRF_ERROR_BUSY	For write with response, procedure already in progress. Wait for a BLE_GATTC_EVT_WRITE_RSP event and retry.
NRF_ERROR_RESOURCES	Too many writes without responses queued. Wait for a BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE event and retry.
NRF_ERROR_TIMEOUT	There has been a GATT procedure timeout. No new GATT procedure can be performed without reestablishing the connection.