Hi Don, On Wed, Nov 23, 2016 at 11:40 PM, Don Zickus <dzickus@xxxxxxxxxx> wrote: > Hi, > > I was trying to write some code to continuously scan the bluetooth field > for bluetooth devices sending advertising packets (ie beacon-mode). That is tricky, if you have anyone else trying to use the adapter in this situation it will probably be blocked, we may add support for setting intervals but that will probably be a best effort in case there is no connection or other usage of the adapter by the system. > These devices would come and go so I wanted to avoid the cache. Beacon are not normally not connectable, connections and continuous advertisement don't go well together so we will probably have to reduce the intervals in order to maintain any traffic on the connections. > I noticed the D-Bus interface doesn't quite allow me to do this (as it > caches the devices and I can't monitor the RSSI field). But I think the > bluetooth management interface does. Is that the correct approach? Yep you could in theory use the MGMT interface and manually add you beacon management on top, but I guess you don't want applications to do that since it would require root permissions to connect to the management socket, so making bluetoothd, via kernel?, to adjust the intervals is probably a better idea in the long run. We would probably have to maintain the biggest advertising window possible, and the consider: 1. Is it connectable/there any advertising instance that is connectable? If yes, the it has to adjust the window to allow them (perhaps using the default connection parameters). 2. In case of a connection is made the controller may not be able to advertise anymore, and in case it can still advertise we need to make sure it doesn't interrupt the connection (this is not very clear if the controller is suppose to manage this somehow). 3. Similar to the connection situation we may have application scanning, again there might be problems if the controller cannot scan while advertising we would probably have to stop advertising. -- Luiz Augusto von Dentz -- 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
