org.bluez.GattCharacteristic - BlueZ D-Bus GattCharacteristic API documentation

GATT local/server and remote/client characteristic attribute representation share the same high-level D-Bus API. Local/Server refers to GATT based characteristics exported by a plugin or an external application. Remote/Client refers to GATT characteristics exported by the peer.

ClientService org.bluez Interface org.bluez.GattCharacteristic1 Objectpath [variable prefix]/{hci0,hci1,...}/dev_XX_XX_XX_XX_XX_XX/serviceXX/charYYYY ServerService unique name Interface org.bluez.GattCharacteristic1 Objectpath freely definable Methodsarray{byte}ReadValue(dictoptions) Issues a request to read the value of the characteristic and returns the value if the operation was successful. Possible options: uint16offset Read start offset in bytes. uint16mtu(serveronly) Exchange MTU in bytes. objectdevice(serveronly) Device object. stringlink(serveronly) Link type. Possible values: "BR/EDR""LE" Possible Errors: org.bluez.Error.Failed Possible values: string 0x80 - 0x9f org.bluez.Error.InProgressorg.bluez.Error.NotPermittedorg.bluez.Error.NotAuthorizedorg.bluez.Error.InvalidOffsetorg.bluez.Error.NotSupportedvoidWriteValue(array{byte}value,dictoptions) Issues a request to write the value of the characteristic. Possible options: uint16offset Write start offset in bytes. stringtype Possible values: "command" Use Write without response procedure. "request" Use Write with response procedure. "reliable" Use Reliable Write procedure. uint16mtu Exchanged MTU (Server only). objectdevice Device path (Server only). stringlink Link type (Server only). Possible values: "BR/EDR""LE"booleanprepare-authorize True if prepare authorization request. Possible Errors: org.bluez.Error.Failed Possible values: string 0x80 - 0x9f org.bluez.Error.InProgressorg.bluez.Error.NotPermittedorg.bluez.Error.InvalidValueLengthorg.bluez.Error.NotAuthorizedorg.bluez.Error.NotSupportedorg.bluez.Error.ImproperlyConfiguredfd,uint16AcquireWrite(dictoptions)[optional] Acquire file descriptor and MTU for writing. Only sockets are supported. Usage of WriteValue will be locked causing it to return NotPermitted error. For server the MTU returned shall be equal or smaller than the negotiated MTU. For client it only works with characteristic that has WriteAcquired property which relies on write-without-response Flag. To release the lock the client shall close the file descriptor, a HUP is generated in case the device is disconnected. Note: the MTU can only be negotiated once and is symmetric therefore this method may be delayed in order to have the exchange MTU completed, because of that the file descriptor is closed during reconnections as the MTU has to be renegotiated. Possible options: objectdevice Object Device (Server only). uint16mtu Exchanged MTU (Server only). stringlink Link type (Server only). Possible values: "BR/EDR""LE" Possible Errors: org.bluez.Error.Failedorg.bluez.Error.NotSupportedfd,uint16AcquireNotify(dictoptions)[optional] Acquire file descriptor and MTU for notify. Only sockets are support. Usage of StartNotify will be locked causing it to return org.bluez.Error.NotPermitted. For server the MTU returned shall be equal or smaller than the negotiated MTU. Only works with characteristic that has NotifyAcquired property which relies on presence of "notify"or"indicate"Flag and no other client have called StartNotify(). Notification are enabled during this procedure so StartNotify() shall not be called, any notification will be dispatched via file descriptor therefore the Value property is not affected during the time where notify has been acquired. To release the lock the client shall close the file descriptor, a HUP is generated in case the device is disconnected. As a client if indication procedure is used the confirmation is generated automatically once received, for a server if the file descriptor is writable (POLLOUT) then upon receiving a confirmation from the client one byte (0x01) is written to the file descriptor. Note: the MTU can only be negotiated once and is symmetric therefore this method may be delayed in order to have the exchange MTU completed, because of that the file descriptor is closed during reconnections as the MTU has to be renegotiated. Possible options: objectdevice Object Device (Server only). uint16mtu Exchanged MTU (Server only). stringlink Link type (Server only). Possible values: "BR/EDR""LE" Possible Errors: org.bluez.Error.Failedorg.bluez.Error.NotSupportedorg.bluez.Error.NotPermittedvoidStartNotify() Starts a notification session from this characteristic if it supports value notifications or indications. Possible Errors: org.bluez.Error.Failedorg.bluez.Error.NotPermittedorg.bluez.Error.InProgressorg.bluez.Error.NotConnectedorg.bluez.Error.NotSupportedvoidStopNotify() Stops or cancel session previously created by StartNotify(). Note that notifications from a characteristic are shared between sessions thus calling StopNotify will release a single session. Possible Errors: org.bluez.Error.FailedvoidConfirm()[noreply,optional](Serveronly) Confirms value was received. Possible Errors: org.bluez.Error.Failed PropertiesstringUUID[read-only] 128-bit characteristic UUID. objectService[read-only] Object path of the GATT service the characteristic belongs to. array{byte}Value[read-only,optional] The cached value of the characteristic. This property gets updated only after a successful read request and when a notification or indication is received, upon which a PropertiesChanged signal will be emitted. booleanWriteAcquired[read-only,optional] True, if this characteristic has been acquired by any client using AcquireWrite. For client properties is ommited in case 'write-without-response' flag is not set. For server the presence of this property indicates that AcquireWrite is supported. booleanNotifyAcquired[read-only,optional] True, if this characteristic has been acquired by any client using AcquireNotify. For client this properties is ommited in case 'notify' flag is not set. For server the presence of this property indicates that AcquireNotify is supported. booleanNotifying[read-only,optional] True, if notifications or indications on this characteristic are currently enabled. array{string}Flags[read-only] Defines how the characteristic value can be used. See Core spec "Table 3.5: Characteristic Properties bit field", and "Table 3.8: Characteristic Extended Properties bit field". The "x-notify" and "x-indicate" flags restrict access to notifications and indications by imposing write restrictions on a characteristic's client characteristic configuration descriptor. Possible values: "broadcast""read""write-without-response""write""notify""indicate""authenticated-signed-writes""extended-properties""reliable-write""writable-auxiliaries""encrypt-read""encrypt-write""encrypt-notify"(Serveronly)"encrypt-indicate"(Serveronly)"encrypt-authenticated-read""encrypt-authenticated-write""encrypt-authenticated-notify"(Serveronly)"encrypt-authenticated-indicate"(Serveronly)"secure-read"(Serveronly)"secure-write"(Serveronly)"secure-notify"(Serveronly)"secure-indicate"(Serveronly)"authorize"uint16Handle[read-only](ClientOnly) Characteristic handle. uint16Handle[read-write,optional](ServerOnly) Characteristic handle. When available in the server it would attempt to use to allocate into the database which may fail, to auto allocate the value 0x0000 shall be used which will cause the allocated handle to be set once registered. uint16MTU[read-only] Characteristic MTU, this is valid both for ReadValue() and WriteValue() but either method can use long procedures when supported. BlueZ October 2023 ORG.BLUEZ.GATTCHARACTERISTIC(5)

org.bluez.GattCharacteristic - BlueZ D-Bus GattCharacteristic API documentation