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Bluez Bugs
Martijn van Welie edited this page Jun 29, 2020
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There are several know bugs or issues with Bluez
- Cannot read the regulatory characteristic in a A&D 352BLE scale. "ATT error 0x0b" reported
- startNotify does not write descriptors again for devices already on the dbus. Workaround is to remove the device from dbus once it disconnects.
- Connecting immediately after receiving InterfaceAdded signal leads to dbus errors. It seems the object has not fully been created yet. Workaround is to add a delay before connecting.
- Notifications don't always arrive in the right order when the device sends it very fast. No workaround known.
- Most adapters cannot handle scanning and connecting at the same time. Workardound is to stop scanning before connecting.
- The amount of advertisement events received various per BT adapter. For example, the Raspberry Pi gives very few advertisements, +/- once per second while other adapters like the CSR-based dongles give every advertisement sent. Probably a driver issue.
- Internally the discovery is restarted every 10 seconds by Bluez. If you try to stop it at exactly the same time, Bluez will hang and needs to be restarted. Workaround, control discovery yourself by restarting scanning every 8 or 9 seconds.
- It is not possible to successfully connect to every BLE device. This may be because of connection settings like the interval and timeout. However, these cannot be controlled on the application level. You can try tweaking this by manually setting them as described here: tweaking timout