Be very careful while developing application that communicate with Bluetooth / BLE devices and choose Your development platform very carefully.
Lately I did started a personal project to communicate with Bluetooth / BLE device and stumbled upon issues with connectivity. Other, non Qt based, applications were able to connect to the device, but application using Qt were unable even to connect to the device (QBluetoothDeviceDiscoveryAgent was working correctly, QLowEnergyController working correctly, except for…, well, not connecting to the device). This issue was even encountered with my code and simple examples provided with Qt.
After searching for few hours why I did encountered connectivity issue like:
qt.bluetooth.windows: Could not await characteristic read
or:
Error occurred trying to connect to remote device.
I did stumbled upon few posts that stated that updating Windows operating system did resolved connectivity issue. I did indeed had disabled updates (Win 10 Pro) and had some “important security” pending updates, that had to be installed including Bluetooth device driver.
In my case Bluetooth driver update was: Intel Corporation - Bluetooth - 23.130.0.3
And windows update: 2025-04 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems (KB5055518)
After update installed, and before scheduled restart, I did tried application, no single line of code changed, and attempted connection to the device… and all was, and most importantly still is, working fine.
OS restart and Bluetooth / BLE connectivity is still working correctly.
Don’t want to point a finger, but we are talking here about Intel and Microsoft, companies that are worth a lot… to say the least. Not to mention cost that I paid for “my” device and “my” software and wasted time. Money well spend…