Hi Luiz, Thank you so much for your reply. I appreciate it. By "registering the services", do you mean "RegisterApplication()" in https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/test/example-gatt-server#n656? If that is the case, I believe I already registered the services. I checked the files in /var/lib/bluetooth. According to https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/settings-storage.txt#n321, there should be a "[ServiceChanged]" section in the "info" file. But I don't see it in the "info" file. Is there a way to tell the "Service Changed Indication" is actually working? Let's suppose the "Service Changed Indication" is already enabled, is there a way for the mobile app to check on their side to tell which service(s) got changed? Thanks again for your help. On Sun, Jan 24, 2021 at 7:35 PM Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote: > > Hi Kenny, > > On Sun, Jan 24, 2021 at 12:45 AM Kenny Bian <kennybian@xxxxxxxxx> wrote: > > > > Hello, > > > > We implemented a GATT server on Linux in Python. The code is based on > > the code sample(https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/test/example-gatt-server). > > The BlueZ version is 5.48. But we found a problem. The cached data in > > /var/lib/bluetooth caused the mobile app to crash if some > > characteristics are changed. After some research, we found "Under BLE > > standard 'Generic Attribute'(0x1801), there is a Characteristic > > 'Service Changed' (0x2A05) with 'indicate' property", see > > https://github.com/espressif/esp-idf/issues/1777. > > > > The questions we have: > > How to enable the "Service Changed Indication"(0x2A05) in the > > bluetooth? Is there any code example in Python? > > If you are registering the services with Bluetoothd then it should > generate the service change automatically: > > https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/src/gatt-database.c#n1185 > > When a new service is registered it is indicated here: > > https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/src/gatt-database.c#n1452 > > > -- > Luiz Augusto von Dentz
