[Interest] lowEnergyScanner detects ibeacons that are absent

[Blasche Alexander]

The delay between the device disappearing and the scan results being adjust is caused by caching in the Bluetooth stack. On Bluez the default is 2 or 3 mins for cache expiry. I have no data about other platforms. What platform are you on?


In fact in some cases the caching goes even further. Sometimes the details of the disappeared device are cached and when you connect you get data from the cache or the list of the services. This doesn't work on Bluez but I have seen this behavior on WinRT for example.


Unfortunately, there is not much you can do about it.

--

Alex


________________________________
From: Interest <interest-bounces+alexander.blasche=theqtcompany.com at qt-project.org> on behalf of Dmytro Haponov <dmytro.haponov at gmail.com>
Sent: Friday, February 19, 2016 13:16
To: interest at qt-project.org
Subject: [Interest] lowEnergyScanner detects ibeacons that are absent

after creating this topic
https://forum.qt.io/topic/64355/lowenergyscanner-example-shows-absent-devices/2
I was advised to address the question here.

The general question is - how to actively scan for BLE devices that are present at the moment of scan?

Dmytro Haponov
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