Thanks to both of your for your info. I was able to get RSSI iinfo, but it took a little fiddling with the extended_inquiry_info structure but I have it working. I have complete control over the computer but no control over the device. It would be best if I could cause the device to initiate the connection but do not have a practical way to implement. I have seen a couple times when I'm initiating a connection from the computer to one device, another device will initiate a connection to the computer without any explicit prompting on my part. But I need to investigate this further to see if I can reliably repeat this and then if it is a usable side effect. Having only a very limited number of active connection is not a problem for my project. Thanks again, Pax. On Tue, Apr 6, 2010 at 7:53 PM, Peter Dons Tychsen <donpedro@xxxxxxxxxx> wrote: > Hi Iain & Garry, > > On Tue, 2010-04-06 at 20:57 +0100, Iain Hibbert wrote: >> Sure, but consider that the page timeout (time to failure of a >> connection >> attempt) is usually around 20 seconds.. and most Bluetooth controllers >> (that I have tried) can only page a single device at a time.. So, if >> you >> don't know which devices are in range, you might be waiting a *long* >> time >> before you connect to anything.. > > 20 seconds for a "page-timeout" is unusual for the reason you just > mentioned. However, the "link-timeout" is usually around 10-20 seconds, > but that is only applicable if an existing links needs to drop. The page > timeout use usually more like 3-5 seconds. Even if it were as high as > you describe, it is easily re-configurable. Going below ~2 seconds is > not a good idea though as you push the odds of hitting the page-scan > window (i do not remember the exact number, look in the spec). Even > better test it (and tune accordingly). For an application like this you > want a low page-timeout. > > On Tue, 2010-04-06 at 19:11 +0100, Iain Hibbert wrote: >> you will probably find that because the HS device is very limited in >> resources, it does not keep records of more than one paired device. >> So, if >> you pair with another device it forgets about the first and you will >> not >> be able to connect except that you pair it again. > > Many headset devices store store 8 devices they have previously paired > with (the major brands). It is however not a guarantee, so some might > not have it. > >>On Tue, 2010-04-06 at 13:08 -0400, Garry Paxinos wrote: >> Is there a practical upper limit of the number of devices that can be >> bonded to a single computer? > > The number of devices is almost limitless. However, as Iain said, in > theory this cannot be done with one controller as the maximum devices > for a unit is 7. In practice it looks even worse, as many controllers > become unstable if you go beyond 2 links. The link itself also becomes > unstable when many devices are connected, as you run out of air-time > (your radio can only service one at any time), and you risk loosing a > link. I recommend people to stick with one link pr. application if > stability and speed is the name of the game. If not, test it! > > Recently i created a large setup of lots of BT-USB dongles connected via > some hubs to a single box running Bluez. To my delight it was remarkably > easy and stable. The well designed Bluez-API really is a bonus. Doing > this on any other system has only ended in agony. Just having that many > USB devices can cause problems on many systems. This is definitely the > way to go if you are trying to connect to lots of devices in a reliable > way. It is pretty cheap as well, as even good dongles are getting > cheaper even as i type (down to $10-$15)! :-) > > Good luck on your project, > > Thanks, > > /Pedro > -- > 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
