Send Data through BLE to BLE Terminal app

[Selvablaze]

I m using nRF52840 chip, I want to send data through BLE and I am using uart service example. I want to receive those data in some other app, without enabling notification, directly after establishing connection, I want to send data. Any reference for this.

[Hieu]

Hi Selvablaze,

Unfortunately, the Bluetooth Specification requires that Notifications must be enabled before they can be sent.

May I ask why you need to bypass this step? For an app, enabling BLE notifications by default should not take much effort or actual run time.

Hieu

[Selvablaze]

Hi Hieu,

Thank you for the info . I tried connecting to the Nordic device through BLE Terminal app. I can connect through that but can't see data in that terminal so thought of experimenting disabling notifications can lead the service to send data once the connection is established.

[Hieu]

Hi Selvablaze,

I am unfamiliar with BLE Terminal. However, BLE solutions must all follow the spec, and for a GATT Client device to receive notifications, it must write 1 to the Client Characteristic Configuration Descriptor (CCCD) of the Characteristic that it wishes to receive Notifications from. In some app, like our nRF Connect app, this action is wrapped under a simple button that "Enable Notifications."

If you are new to BLE, you might be interested in our free online Fundamentals of Bluetooth Low Energy course.