descriptor

Access a descriptor on Bluetooth Low Energy peripheral device

Description

A descriptor object represents a descriptor of a Bluetooth^® Low Energy peripheral device. If read or write are supported in the object Attributes property, you can read data using read or write data using write.

Creation

Syntax

d = descriptor(c,descriptorName)

d = descriptor(c,descriptorUUID)

Description

d = descriptor(c,descriptorName) creates an object that represents the descriptor specified by its name. Identify descriptorName by viewing the Descriptors property of the characteristic object c.

d = descriptor(c,descriptorUUID) creates an object that represents the descriptor specified by its UUID. Identify descriptorUUID by viewing the Descriptors property of the characteristic object c.

Input Arguments

c — Characteristic of Bluetooth Low Energy peripheral device

characteristic object

Characteristic of Bluetooth Low Energy peripheral device, specified as a characteristic object.

descriptorName — Descriptor name

character vector | string scalar

Descriptor name, specified as a character vector or string scalar. Identify descriptorName in the Descriptors table of the characteristic object. The DescriptorName column lists the valid values.

Example: d = descriptor(c,"Client Characteristic Configuration") creates an object that represents the "Client Characteristic Configuration" descriptor on the characteristic c.

Data Types: char | string

descriptorUUID — Descriptor UUID

character vector | string scalar

Descriptor UUID, specified as a character vector or string scalar. Identify descriptorUUID in the Descriptors table of the characteristic object. The DescriptorUUID column lists the valid values.

Example: d = descriptor(c,"2902") creates an object that represents the descriptor with UUID "2902" on the characteristic c.

Data Types: char | string

Properties

Name — Descriptor name

Read-only: string scalar

This property is read-only.

Descriptor name, returned as a string scalar.

Data Types: string

UUID — Descriptor UUID

Read-only: string scalar

This property is read-only.

Descriptor UUID, returned as a string scalar. This value is specific to each descriptor.

Data Types: string

Attributes — Descriptor attributes

Read-only: string array

This property is read-only.

Descriptor attributes that describe the read and write permissions, returned as a string array. Possible values follow.

Value	Description
"Read"	Descriptor is readable using read
"Write"	Descriptor is writable using write

Data Types: string

Object Functions

read	Read characteristic or descriptor data on a Bluetooth Low Energy peripheral device
write	Write data to a characteristic or descriptor on a Bluetooth Low Energy peripheral device

Examples

Access a Descriptor on a Bluetooth Low Energy Peripheral Device

Create a connection to a nearby Bluetooth Low Energy peripheral device.

b = ble("Thingy")

b = 
  ble with properties:

               Name: "Thingy"
            Address: "F2DF635320F6"
          Connected: 1
           Services: [9×2 table]
    Characteristics: [38×5 table]

Show services and characteristics

Create a characteristic object that represents the "Temperature" characteristic.

c = characteristic(b,"Weather Station Service","Temperature")

c = 
  Characteristic with properties:

             Name: "Temperature"
             UUID: "EF680201-9B35-4933-9B10-52FFA9740042"
       Attributes: "Notify"
      Descriptors: [1x3 table]
 DataAvailableFcn: []

Show descriptors

List the descriptors for the characteristic.

c.Descriptors

ans=1×3 table
               DescriptorName                DescriptorUUID     Attributes 
    _____________________________________    ______________    ____________

    "Client Characteristic Configuration"        "2902"        {1×2 string}

Create a descriptor object that represents "Client Characteristic Configuration".

d = descriptor(c,"Client Characteristic Configuration")

d = 
  Descriptor with properties:

          Name: "Client Characteristic Configuration"
          UUID: "2902"
    Attributes: ["Read"    "Write"]

Alternatively, you can use the UUID instead of the name to create the object.

d = descriptor(c,"2902")

d = 
  Descriptor with properties:

          Name: "Client Characteristic Configuration"
          UUID: "2902"
    Attributes: ["Read"    "Write"]

This object represents the "Client Characteristic Configuration" descriptor. Since it has both Read and Write attributes, you can use read or write.

Version History

Introduced in R2019b