subscribe - Subscribe to characteristic notification or indication - MATLAB (original) (raw)
Main Content
Subscribe to characteristic notification or indication
Syntax
Description
subscribe([c](#mw%5Fd0423e81-c609-486d-8d1e-3313c714ce82))
subscribes to a characteristic notification or indication of a Bluetooth® Low Energy peripheral device. Notification or indication depends on theAttributes
property of the characteristic c
. The property must contain "Notify"
, "Indicate"
, or both. If the property contains both "Notify"
and "Indicate"
, the function subscribes to notification.
subscribe([c](#mw%5Fd0423e81-c609-486d-8d1e-3313c714ce82),[type](#mw%5F921805a5-19cd-4d08-a4ea-e4c7739a5e18))
subscribes to a characteristic of a Bluetooth Low Energy peripheral device and specifies whether the subscription is for notification or indication. The Attributes
property of the characteristic c
must contain the specifiedtype
.
Examples
Subscribe to a characteristic that supports notification or indication. Unsubscribe after you finish working with the characteristic.
Create a connection to a nearby Bluetooth Low Energy peripheral device.
b = ble with properties:
Name: "DemoDev"
Address: "FF548EA5658F"
Connected: 1
Services: [5×2 table]
Characteristics: [10×5 table]
Show services and characteristics
Create a characteristic object that represents the "Heart Rate Measurement"
characteristic.
c = characteristic(b,"Heart Rate","Heart Rate Measurement")
c = Characteristic with properties:
Name: "Heart Rate Measurement"
UUID: "2A37"
Attributes: "Notify"
Descriptors: [1x3 table]
DataAvailableFcn: []
Show descriptors
This characteristic supports "Notify"
.
Start receiving notifications using subscribe
.
Read from the characteristic to check that you are receiving data.
ans = 1×19
23 14 1 187 1 186 1 185 1 184 1 183 1 182 1 181 1 180 1
After you finish working with the characteristic, disable notifications using unsubscribe
.
Input Arguments
Characteristic of Bluetooth Low Energy peripheral device, specified as a characteristic object.
Example: subscribe(c)
subscribes to notification or indication on the characteristic object c
, depending on theAttributes
property of c
.
Subscription type, specified as "notification"
or"indication"
. If a characteristic supports both and you do not specify type, then the default value is "notification"
.
Possible behaviors of subscribe
follow.
c.Attributes includes | Notification supported? | Indication supported? |
---|---|---|
"Notify" | Yes, using subscribe(c) orsubscribe(c,"notification") | No |
"Indicate" | No | Yes, using subscribe(c) orsubscribe(c,"indication") |
"Notify" and "Indicate" | Yes, using subscribe(c) orsubscribe(c,"notification") | Yes, using subscribe(c,"indication") |
Example: subscribe(c,"indication")
subscribes to indication.
Version History
Introduced in R2019b