In message <[EMAIL PROTECTED]>, David Forbes writes: >My question is: What's a good way to synchronize the RT-Linux OS clock >to the GPS clock? I am considering the use of the A/D card's interrupt >with the 1PPS from GPS. I expect to use NTP to get the correct second.
Don't do it that way, you will get in trouble with the interrupt latency. Get an A/D card which registers a couple of digital bits along with the analog sample, something like a Nudaq 9812/10 for instance. Sync the machine to UTC with NTP and feed a precise PPS signal (ie: from GPS) to the digital pin. When you store your samples on disk, store a timestamp for every block of data. That way you can use the timestamp to decide which UTC second and the digital bit to decide when the second starts. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
