Pardon my ignorance, I'm not sure what COM port the PPS is tied to or what you mean.
-----Original Message----- From: time-nuts [mailto:[email protected]] On Behalf Of Chris Albertson Sent: Monday, August 15, 2016 2:30 AM To: Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to APU2 SoC serial port for ntpd Why not use the same COM port the PPS is tied to. Apparently in can accept the 3 volt serial signal. The PPS goes to one of the control lines to create an interrupt and the data goes to Rx and Tx. On Sun, Aug 14, 2016 at 9:37 AM, STR . <[email protected]> wrote: > Thanks for your previous email, it shed light on the situation of > choosing COM ports. > > COM1 is required for console access so that's out. > COM2 has headers and seemed like an obvious choice as I have no real > need for a 2nd serial port. > > I wish to power the GPS via the mini-PCI slot to avoid soldering power > cables along with a PPS line. > Will there be any difference in jitter between using the COM2 header > or > COM3 provided by the NCT5104D GPIO pins? > Or will they both be identical in performance? > > > -----Original Message----- > From: time-nuts [mailto:[email protected]] On Behalf Of > Attila Kinali > Sent: Sunday, August 14, 2016 5:30 PM > To: Discussion of precise time and frequency measurement < > [email protected]> > Subject: Re: [time-nuts] How to get PPS from ublox mini-PCI GPS to > APU2 SoC serial port for ntpd > > On Sun, 14 Aug 2016 08:29:48 +0000 > "STR ." <[email protected]> wrote: > > > Serial port 3 and 4 are provided via the GPIO pins connected to an > NCT5104D I/O controller which is 5V tolerant. > > http://datasheet.octopart.com/NCT5104D-Nuvoton-datasheet-38893851.pd > > f I believe that's why it was suggested to avoid the 3V-5V > > conversion. > > Oops.. I missed that the other UARTs were connected to the GPIO header. > > If you use those, you can directly connect the LEA outputs, as the LEA > does use 3.3V CMOS for I/O. > > Attila Kinali > -- > Malek's Law: > Any simple idea will be worded in the most complicated way. > _______________________________________________ > 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. > _______________________________________________ > 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. > -- Chris Albertson Redondo Beach, California _______________________________________________ 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. _______________________________________________ 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.
