Hi Jakub, Thanks for the response. That makes sense - I'll give that a try. I'm running this on a Raspberry Pi with a Medialink USB adapter which (I believe) has a Broadcom chipset. Neil On Thu, Jun 25, 2015 at 9:30 PM, Jakub Pawlowski <jpawlowski@xxxxxxxxxx> wrote: > Hi Neil, > > On Thu, Jun 25, 2015 at 2:53 PM, Neil Martin <neil@xxxxxxx> wrote: >> Hi, >> >> I've noticed that the bluetoothd console output shows a steady stream >> of RSSI updates, yet only a fraction of these seem to translate into a >> DBus PropertiesChanged signal. >> >> I've just seen 50 or so messages from bluetoothd of the form: >> >> bluetoothd[3867]: src/adapter.c:device_found_callback() hci0 addr >> D0:4F:7E:2B:74:31, rssi -91 flags 0x0000 eir_len 15 >> >> while only seeing a single PropertiesChanged signal from dbus-monitor >> with an RSSI update. > > That's because by default there is a threshold of 8db: > > #define RSSI_THRESHOLD 8 > > http://git.kernel.org/cgit/bluetooth/bluez.git/tree/src/device.c#n88 > > So if RSSI is changed less than 8dB you don't get any updates through D-Bus. > > If you want to get updates through D-Bus, you should call > SetDiscoveryFilter first, see doc: > "If one or more discovery filters have been set, the RSSI > delta-threshold, that is imposed by StartDiscovery by default, will > not be applied." > http://git.kernel.org/cgit/bluetooth/bluez.git/tree/doc/adapter-api.txt#n48 > > > Can I ask what kind of controller do you use ? Some just don't do > packet deduplication during scan, and would report all packets > received, that would explain flow of events from kernel. > > Jakub > >> >> Neil >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
