On Fri, 2010-12-03 at 09:01 -0500, Brian K. White wrote:
Interesting problem. I love how it exemplifies how "progress often isn't".
Maybe get a head start by licensing a reduced version of this that only has to keep two nodes in sync, the pc and the gps.
Only keep two things in sync... That's no fun. We are also syncing images from firewire/Gig<E>Vision/JPEG2000/v4l2 cameras, vehicle movement from linear pulse transducers, an assortment of lasers, accelerometers, inclinometers, gyroscopes, and other devices I am surely forgetting. Oh, and of course operator input in all this. That one is the nastiest one to deal with in X11 systems (who's concept of time is relative to when the X server started - not the systems' clock).
This sounds interesting. But I wonder how this really works when USB is a packet-based system on which all devices must share access. I suspect this is a sort of fast hub that accepts packets from each connected device immediately and then time tags each packet from the devices as they pass through, allowing you to check this encapsulated info on the host via a driver that can peel off the time wrapper. As long as you can assume there is no delay getting it in to this hub, I guess this could improve time tagging. I will bookmark this one.
It's the only thing I find at all when I google for variations of synchronous, deterministic, high precision, timing, and usb.
I would have thought every dinky usb sound card would need good timing, and usb modems that expect to fax reliably. But then again, my incredulity doesn't matter because current bluetooth A2DP audio devices continue to have have wow (speed skew, as in "wow & flutter" like records and tapes had, but no flutter) no matter how incredulous I am about it. I mean, CD's had no wow since 1982, laserdiscs had no wow since 1978. Why in 2010 do several different smart phones (different OS's different manufacturers, used with different receivers both in car and in home) have wow when playing audio over bluetooth?
Progress often isn't.
Still, USB has generally made connecting many types of peripherals much easier. I have no trouble with it for many uses. My new laptop has USB3, but I have no devices to test with. I wonder what a 10x speed improvement will really mean. Probably that all devices will get more verbose, and just fill the capacity with, effectively, the same content. I'm showing the telltale sings of age here... -- Roger Oberholtzer OPQ Systems / Ramböll RST Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org