From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: "Rob Raper" To: bluez-users@lists.sourceforge.net Subject: Re: [Bluez-users] What's the best way to go about device detection? Mime-Version: 1.0 Content-Type: text/plain; format=flowed Message-ID: Sender: bluez-users-admin@lists.sourceforge.net Errors-To: bluez-users-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sun, 16 May 2004 22:35:44 -0700 Without involving any of my source code at alll, I can demonstrate one of my biggest problems. I'll first create a connection to an existing bluetooth device. It works fine. I can get an RSSI value or link value. Then, I'lll try a non-existent device. I get a connection timed out error fairly quickly. Great, that's exactly what I want and what I expect. What follows, however, is what is really causing me problems. I can no longer connect to the valid bt device. I just get errors for a long time. I can't disconnect either. How can I clear out the failed connection and move on without everything breaking down like this? pluto62:~/bluez-utils-2.4/tools# hcitool cc 00:60:57:23:35:15 pluto62:~/bluez-utils-2.4/tools# hcitool rssi 00:60:57:23:35:15 RSSI return value: -1 pluto62:~/bluez-utils-2.4/tools# hcitool dc 00:60:57:23:35:15 So far so good...Now try an invalid address pluto62:~/bluez-utils-2.4/tools# hcitool cc 00:60:57:23:35:14 Can't create connection: Connection timed out As expected. pluto62:~/bluez-utils-2.4/tools# hcitool dc 00:60:57:23:35:14 Disconnect failed: Input/output error Why an input/output error? It's on the con list, how do I get it off? pluto62:~/bluez-utils-2.4/tools# hcitool cc 00:60:57:23:35:15 Can't create connection: Input/output error Uh oh.. why can't I connect to the bt adapter that worked before? >From: Marcel Holtmann >To: Rob Raper >CC: BlueZ Mailing List >Subject: Re: [Bluez-users] What's the best way to go about device >detection? >Date: Sun, 16 May 2004 22:20:24 +0200 > >Hi Rob, > > > Thanks for your reply. I'll have a look into RSSI. Is it > > possible to use RSSI for detection, but then use RFCOMM to do the actual > > communications? Once "linked" to a server they don't ever need to >talk to > > multiple servers at the same time. It's just that other servers need to > > determine signal strength in order to decide when to perform a hand off. > >this is what I said. The RSSI comes for free with an inquiry with RSSI >command from the Bluetooth 1.2 specification. And while a connection is >active you can retrieve it without any extra cost. Look at the hcitool >info command and see how it finds the needed ACL handle of an existing >connection. > >And btw check your devices that they really support inquiry while they >maintain an open ACL connection. > > > Here's the block of code that I'm currently using to do a scan. The old > > version which worked better was simply a verison of the "hcitool scan" > > routine modified to connect and check singal strength. > >Sorry, but I won't read that code. It is too much nested and actually >code that needs more than 80 chars in a row is way too complex. > >Regards > >Marcel > > > > >------------------------------------------------------- >This SF.Net email is sponsored by: SourceForge.net Broadband >Sign-up now for SourceForge Broadband and get the fastest >6.0/768 connection for only $19.95/mo for the first 3 months! >http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click >_______________________________________________ >Bluez-users mailing list >Bluez-users@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/bluez-users _________________________________________________________________ Watch LIVE baseball games on your computer with MLB.TV, included with MSN Premium! http://join.msn.click-url.com/go/onm00200439ave/direct/01/ ------------------------------------------------------- This SF.Net email is sponsored by: SourceForge.net Broadband Sign-up now for SourceForge Broadband and get the fastest 6.0/768 connection for only $19.95/mo for the first 3 months! http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click _______________________________________________ Bluez-users mailing list Bluez-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bluez-users