Thank you very much for your help. Apparently, netbsd 5.0 still doesn't support GPZDA string so when i enabled the GPGGA string which was initially disabled in our system, the serial port was able to read nmea and pps signals and is able to synchronize the two signals. I found the kernel PPS_SYNC option giving more stable and accurate values more than enabling PPS driver. Thank you very much for your help I appreciate it : )
Runa Dahal On Mon, Jul 13, 2009 at 10:13 AM, Daniel Hagerty <[email protected]> wrote: > For the list: netbsd 5.0's ntpd looks to be 4.2.4p6 (gleaned from > source). > > Runa Dahal <[email protected]> writes: > > > I am using NetBSD 5.0 operating system in a low powered embedded computer > > used solely for the purpose of NTP. I have enabled options PPS_SYNC > option > > in the kernel and rebuilt it. My ntp.conf file has the following set up: > [...] > > I'm using approximately the following on netbsd-4.0 with a NMEA > GPS emitting GPGGA sentences: > > server 127.127.20.1 mode 2 prefer > fudge 127.127.20.1 flag3 1 > > server 127.127.22.1 > fudge 127.127.22.1 flag3 1 refid GPS > > NetBSD 4.0's ntpd is too old to support GPZDA. A quick reading of > the source for netbsd 5.0's ntpd suggests no improvement in this > department. > > Even if your ntpd supports it, you'll need to replace the "mode 2" > I use above with a "mode 8". > > > I have a couple questions regarding NMEA PPS. If I am using kernel PPS > > discipline, then do I not need to specify ntpd atom pps(22) driver? I > know I > > need to have flag3 1 flag. Can I use ntpd PPS driver instead of kernel > PPS > > even with NetBSD being compiled PPS_SYNC, so, that I could easily switch > > being either for testing. Do I always need to specify flag1 1 since I > need > > PPS ? > > You can have a kernel with PPS_SYNC where ntpd doesn't use it. > Just drop the "flag3 1" options from the nmea and pps drivers. > I spent some time experimenting myself to come up with what I'm > currently using, and wasn't about to reboot to do it :) > > _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
