Bluetooth Low Energy Duplicate Notifications

User10101010 1 Reputation point
2021-09-10T13:58:04.687+00:00

Hello, I've recently discovered an issue with Bluetooth Low Energy on Windows 10 using UWP libraries as part of a C# WinForms application. Connection and data transfer to a our custom PCBs work as expected until multiple devices are connected. Each device connection is managed in a separate instance of a BLE Comms class implementing Windows.Devices.Bluetooth.

When more than one device is connected the GattCharacteristic.ValueChanged event handler is triggered multiple times per device depending on the number of devices connected. For example if two devices are connected, we receive 2 copies of the same notification, if three devices are connected we receive 3 copies. The copies have been confirmed to be so through use of different dummy data on each of the devices and count variables within the notification data.

I have checked that this is not due to multiple erroneous subscriptions. Additionally, this behaviour also occurs in Matlab, although it manifests slightly differently i.e. two copies appear for every notification when only a single device is connected. A colleague and I have tested this on separate machines with both programs and multiple BLE dongles producing the same behaviour.

This leads me to believe there may be some form of driver issue as the system attempts to manage multiple connections or a bug in the UWP BLE library. If anybody has useful experience/input relating to this issue it would be much appreciated.

Windows Forms
Windows Forms
A set of .NET Framework managed libraries for developing graphical user interfaces.
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Universal Windows Platform (UWP)
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