May peripheral could auto connect to central

RE: May peripheral could auto connect to central

Karl Ylvisaker — Thu, 04 Jun 2020 13:24:52 GMT

Hello again,

[quote user="zyj"]why sony earphone could auto connect and NRF can not?[/quote]

This has to do with the iOS/Android default Bluetooth adapter configuration. Typically, I would think they allow this for HID and/or Audio devices only.
So, if this is to work for your nRF, it depends on what your nRF device will be doing, as @awneil suggests.
For example, if you intend for your nRF to stream sensor data to your phone, then you will have to create a custom application on your phone that connects to your nRF device, and collects/processes the sensor data. Your phone will not do this automatically.

Be advised of the differentiation between Bluetooth Classic and Bluetooth Low-Energy handling when reading iOS/Android documentation. nRF devices supports Bluetooth Low-Energy only.

Best regards,
Karl

RE: May peripheral could auto connect to central

awneil — Thu, 04 Jun 2020 10:34:17 GMT

You're welcome.

RE: May peripheral could auto connect to central

zyj — Thu, 04 Jun 2020 10:28:24 GMT

get it ! thank you for your kind help!

RE: May peripheral could auto connect to central

awneil — Thu, 04 Jun 2020 10:25:40 GMT

But how that works is that the earphone advertises, the phone sees it, and it is the phone which automatically initiates the connection.

So you need to write your app to do that

RE: May peripheral could auto connect to central

zyj — Thu, 04 Jun 2020 09:56:35 GMT

but my sony earphone could connect to my smart phone after it power on ,and i want my NRF do like this.

why sony earphone could auto connect and NRF can not?

RE: May peripheral could auto connect to central

Karl Ylvisaker — Thu, 04 Jun 2020 09:53:29 GMT

Hello,

As awneil said, the decision to connect is entirely in the hands of the central, the peripheral will only advertise its presence and the possibility to connect with it. For a smartphone central, you would need to know how the smartphone is configured to handle automatic reconnections.
For this, you should check out Android/iOS specifications on how often their Bluetooth modules behave. For instance, Androids will by default only listen for and autoconnect to their previous connection, if I recall correctly.

Best regards,
Karl

RE: May peripheral could auto connect to central

awneil — Thu, 04 Jun 2020 09:30:09 GMT

[quote userid="77819" url="~/f/nordic-q-a/62158/may-peripheral-could-auto-connect-to-central"] I hope that the NRF can actively connect with the newly connected central device.[/quote]

It's not an nRF thing - it's the way the BLE protocol is defined to work.

The peripheral advertises when it is ready to connect - the decision on when/whether to connect is entirely with the Central.