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3.3.2 <properties> : Characteristic Properties element
The XML element is used to define the properties of a characteristic. A characteristic may have <properties>
one or more properties. The attributes are described in more detail in the table below. Possible values for all
attributes are or and in all cases default value is false.true false
Attribute Description
read
This attribute defines that a characteristic value can be read over a Bluetooth
connection using the procedure.Attribute Read
const
This attribute defines that the characteristic value is stored in flash memory and that it
cannot be modified after programming.
The benefit of constant values is that no RAM is allocated for them leaving more
RAM to the application.
If the const attribute is not used the data must be initialized during runtime.
write
This attribute defines that the characteristic value can be written over a Bluetooth
connection using the procedure.Attribute Write
write_no_response This attribute defines that the characteristic value can be written only using the Write
procedure.Without Response
Note that this means the write operation is not confirmed over the attribute protocol
unlike the regular write operation.
notify
This attribute defines that the characteristic value can be notified.
Notification is confirmed over the attribute protocol.not
indicate
This attribute defines that the characteristic value can be indicated.
Indication is confirmed over the attribute protocol.
authenticated_read
This attribute defines that reading the characteristic value over a Bluetooth
connection requires that the devices are bonded using MITM protection and
connection is encrypted.
NOTE! Attribute must be set to . read "true"
authenticated_write
This attribute defines that writing the characteristic value over a connection Bluetooth
requires that the devices are bonded using MITM protection and connection is
encrypted.
NOTE! Attribute must also be set to . write or write_no_response "true"
authenticated_notify
This attribute defines that Notifications and Indications require that the devices are
bonded using MITM protection and connection is encrypted. This attribute is only
valid with the Bluetooth stack in the BT121.
NOTE! Attribute must also be set to . or notify indicate "true"
encrypted_read
This attribute defines that reading the characteristic value over a Bluetooth
connection requires that the connection is encrypted. With iOS 9.1 and newer,
devices must also be bonded at least with Just Works pairing. This attribute is only
valid with the Bluetooth stack in the BT121.
NOTE! Attribute must be set to . read "true"