On Mon, Aug 13, 2018 at 09:43:13AM -0500, Keith Squier wrote: > How do I feed the 1 PPS to the PHC? Do I use phc2sys?
No, you must physically connect the output pin of the GPS to the input pin of your MAC. (Of course, make sure the signals are compatible!) > What API do I use to > read the 1 PPS time stamps from the PHC and set the PHC? It is the same Linux PTP Hardware Clock API we use for everything. See the testptp.c program in the Linux kernel sources. > Instead of feeding the PPS to the PHC, reading the time stamps from the > PHC, and then setting the PHC to match the GPS time, wouldn't it be better > to have a separate program that reads the PPS and time from the GPS and > sets the PHC? This is exactly what I am suggesting. > Of course, then I wonder what the point of the PPS is if I > have the time from the GPS. If you don't use the PPS, then the PHC won't be synchronized to the GPS. You want to be a GM, right? > Is it really this difficult to synchronize a system to a GPS receiver, or > am I overthinking things? Yes, it is difficult, but it isn't rocket science either. HTH, Richard ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linuxptp-users mailing list Linuxptp-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-users
