[email protected] said: > It can be done entirely from user space as well.
> /* wait till a serial port status change interrupt is generated */ > if (ioctl(fd, TIOCMIWAIT, TIOCM_CD | TIOCM_CTS | TIOCM_DSR)!=0) Yup. gpsd uses it. As far as I know, it's only available on Linux. I can't find it on FreeBSD or NetBSD. Does anybody know if Windows supports it? The advantage is that it doesn't need PPS support, but that's in modern Linux kernels. The disadvantage is that there is more code between the interrupt and grabbing the time stamp and hence more opportunity for jitter. (A constant delay is not a problem. That can be subtracted out if it matters, but for tracking 60 Hz a constant offset doesn't matter.) -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
