BluetoothGATTSetCharacteristicValue function

The BluetoothGATTSetCharacteristicValue function writes the specified characteristic value to the Bluetooth device.

Syntax

HRESULT BluetoothGATTSetCharacteristicValue(
  HANDLE                             hDevice,
  PBTH_LE_GATT_CHARACTERISTIC        Characteristic,
  PBTH_LE_GATT_CHARACTERISTIC_VALUE  CharacteristicValue,
  BTH_LE_GATT_RELIABLE_WRITE_CONTEXT ReliableWriteContext,
  ULONG                              Flags
);

Parameters

hDevice

Handle to the service.

Characteristic

Pointer to BTH_LE_GATT_CHARACTERISTIC structure containing the parent characteristic.

CharacteristicValue

Pointer to BTH_LE_GATT_CHARACTERISTIC_VALUE structure containing the characteristic value.

ReliableWriteContext

BTH_LE_GATT_RELIABLE_WRITE_CONTEXT structure containint the context describing the reliable write operation returned from a previous call to BluetoothGATTBeginReliableWrite.

Flags

Flags to modify the behavior of BluetoothGATTSetCharacteristicValue:

Flag Description
BLUETOOTH_GATT_FLAG_NONE The client does not have specific GATT requirements (default).
BLUETOOTH_GATT_FLAG_CONNECTION_ENCRYPTED The client requests the data to be transmitted over an encrypted channel.
BLUETOOTH_GATT_FLAG_CONNECTION_AUTHENTICATED The client requests the data to be transmitted over an authenticated channel.
BLUETOOTH_GATT_FLAG_WRITE_WITHOUT_RESPONSE Write without response.
BLUETOOTH_GATT_FLAG_SIGNED_WRITE Signed write. Profile drivers must use with BLUETOOTH_GATT_FLAG_WRITE_WITHOUT_RESPONSE in order to produce signed write without a response.

Return Value

The BluetoothGATTSetCharacteristicValue function returns the following values:

Return code Description
S_OK
The operation completed successfully.
ERROR_ACCESS_DENIED
Returned if both a parent service and a service handle are provided and the service hierarchy does not roll up to the provided parent service handle.
ERROR_INVALID_PARAMETER
A parameter was invalid.
ERROR_BAD_NET_RESP
The target server did not provide an appropriate network response.
ERROR_SEM_TIMEOUT
The request timed-out.
ERROR_NO_SYSTEM_RESOURCES
The operation ran out of memory.
ERROR_INVALID_FUNCTION
A reliable write operation is already presently underway.
E_BLUETOOTH_ATT_INVALID_HANDLE
The attribute handle given was not valid on this server.
E_BLUETOOTH_ATT_READ_NOT_PERMITTED
The attribute cannot be read.
E_BLUETOOTH_ATT_WRITE_NOT_PERMITTED
The attribute cannot be written.
E_BLUETOOTH_ATT_INVALID_PDU
The attribute PDU was invalid.
E_BLUETOOTH_ATT_INSUFFICIENT_AUTHENTICATION
The attribute requires authentication before it can be read or written.
E_BLUETOOTH_ATT_REQUEST_NOT_SUPPORTED
Attribute server does not support the request received from the client.
E_BLUETOOTH_ATT_INVALID_OFFSET
Offset specified was past the end of the attribute.
E_BLUETOOTH_ATT_INSUFFICIENT_AUTHORIZATION
The attribute requires authorization before it can be read or written.
E_BLUETOOTH_ATT_PREPARE_QUEUE_FULL
Too many prepare writes have been queued.
E_BLUETOOTH_ATT_ATTRIBUTE_NOT_FOUND
No attribute found within the given attribute handle range.
E_BLUETOOTH_ATT_ATTRIBUTE_NOT_LONG
The attribute cannot be read or written using the Read Blob Request.
E_BLUETOOTH_ATT_INSUFFICIENT_ENCRYPTION_KEY_SIZE
The Encryption Key Size used for encrypting this link is insufficient.
E_BLUETOOTH_ATT_INVALID_ATTRIBUTE_VALUE_LENGTH
The attribute value length is invalid for the operation.
E_BLUETOOTH_ATT_UNLIKELY
The attribute request that was requested has encountered an error that was unlikely, and therefore could not be completed as requested.
E_BLUETOOTH_ATT_INSUFFICIENT_ENCRYPTION
The attribute requires encryption before it can be read or written.
E_BLUETOOTH_ATT_UNSUPPORTED_GROUP_TYPE
The attribute type is not a supported grouping attribute as defined by a higher layer specification.
E_BLUETOOTH_ATT_INSUFFICIENT_RESOURCES
Insufficient Resources to complete the request.
E_BLUETOOTH_ATT_UNKNOWN_ERROR
An error that lies in the reserved range has been received.

Remarks

Calling BluetoothGATTSetCharacteristicValue after BluetoothGATTBeginReliableWrite, notifies the remote Bluetooth device to store this request into a prepare queue on the device.

If signing is required, then the operation must not require a response, and must not occur over a secure channel.

The parent characteristic is returned from a previous call to BluetoothGATTGetCharacteristics, and must not be altered. Behavior is undefined if the caller does this.

Example

C++
BTH_LE_GATT_CHARACTERISTIC_VALUE newValue;

RtlZeroMemory(&newValue,(sizeof(newValue)));

newValue.DataSize = sizeof(valueData); newValue.Data = (UCHAR*)&valueData;

// Set the new characteristic value hr = BluetoothGATTSetCharacteristicValue(hDevice, parentCharacteristic, &newValue, NULL, BLUETOOTH_GATT_FLAG_NONE);

Requirements

   
Windows version Supported in Windows 8 and later versions of Windows.
Target Platform Universal
Header bluetoothleapis.h
Library BluetoothAPIs.lib
DLL BluetoothAPIs.dll

See Also

BTH_LE_GATT_CHARACTERISTIC

BTH_LE_GATT_CHARACTERISTIC_VALUE