[quoted lines by Jackie McBride on 2018/05/18 at 15:03 -0700] >So might I ask--what does that really do, as it appears the device had >actually been discovered. Or am I misinterpreting the log?
No, you aren't missing anything in the log. You just lack a bit of knowledge about how Bluetooth works. I'd say that'd be a rather common weakness that most people suffer from. :-) The BrailleNote Touch, just like lots of other braille devices, implements Bluetooth communication by emulating a serial port. Emulating a serial port over Bluetooth uses a protocol called RFCOMM, which, for the purposes of simplistic explanation, is kind of analogous to the TCP/IP protocol on a network. It supports several services (which Bluetooth calls profiles) running simultaneously, with each one using a different RFCOMM channel. Again, for the purposes of a simplistic explanation, you can think of RFCOMM channels as being kind of like TCP/IP ports. So, yes, the device was detected. The problem was determining which RFCOMM channel to use. Some braille devices (mostly the older ones) always use the same channel, so brltty drivers have the capability to define which channel to use. Other braile devices (most of the newer ones) use a channel that's dynamically assigned when their Bluetooth interface is started. For those, it's necessary for the host to ask the device which channel to use for its Serial Port Profile. this is done via Bluetooth's Service Discovery Profile, so brltty drivers also have the capability to request that service discovery be performed. The bug was that the HumanWare braille driver wasn't requesting that service discovery be performed. This has been fixed within the development code. The discovery=yes device parameter is the way to manually request service discovery. >BTW. I'm just curious, you understand. Of course! Curiosity like yours is encouraged on this list. -- I believe the Bible to be the very Word of God: http://Mielke.cc/bible/ Dave Mielke | 2213 Fox Crescent | WebHome: http://Mielke.cc/ EMail: [email protected] | Ottawa, Ontario | Twitter: @Dave_Mielke Phone: +1 613 726 0014 | Canada K2A 1H7 | _______________________________________________ This message was sent via the BRLTTY mailing list. To post a message, send an e-mail to: [email protected] For general information, go to: http://brltty.app/mailman/listinfo/brltty
