Christian Weisgerber <[email protected]> wrote: > Stuart Henderson: > > > > I don't have any practical experience with nmea(4), but I'd like > > > to draw attention to ldattach(8)'s -t option. Unless your receiver > > > offers a pulse per second signal, you are limited to a very jittery > > > timestamp from the serial telegram, mirroring udcf's fundamental > > > problem. > > > > The problem isn't getting the pulses generated, it's getting > > them hooked up to the computer and figuring out accurately > > when they occurred. > > That's why I mentioned ldattach -t. We can timestamp on DCD or CTS > transitions. On a real serial port, those will trigger an interrupt. > That shouldn't be too bad.
Correct. > I see that we also have code for timestamping on ucom(4), but since > USB devices cannot directly generate interrupts and are in fact > polled by the host controller, that will give poor results. Correct.
