Re: [time-nuts] GPS NTP update on Mac OS-X 10.7.4
I recently connected up a USB GPS to my Linux box and found it quite easy to
get NTP to up from the GPS. I was hoping to get the same GPS to update the
Mac running Lion 10.7.4, however, it has been a very frustrating uphill
battle.
Has anybody managed to get GPS NTP update working on OS-X?
You will probably get much better answers to NTP questions over on the NTP
lists.
http://lists.ntp.org/listinfo
Down near the bottom is questions
GPS over USB generally doesn't work very well. You will probably get better
results over the net.
The problem isn't USB polling, it's firmware that adds about 100 ms of
wander. By wander I mean low frequency drift. It's too slow to filter out.
Here is a graph from a SiRF III, the most common chipset in low cost USB GPS
devices. Most others are similar.
http://www.megapathdsl.net/~hmurray/ntp/GPSSiRF-off.gif
If anybody finds a good one, please let me know.
I did a sum link to /dev/gps0 and can cat the output and see the NMEA stream
of alternate $GPRMC and $GPZDA messages,
I just cannot get it to accept the gps as a peer.
The GPRMC sentence has a flag to tell you if it is seeing enough satellites.
Are you seeing A or V? I think A is good and V is bad.
--
These are my opinions. I hate spam.
On Wed, Jun 13, 2012 at 3:08 AM, Hal Murray hmurray@megapathdsl.net wrote:
Has anybody managed to get GPS NTP update working on OS-X?
Yes, All Macs come with NTP already installed. (Version 4.2.6) All
you need to do is replace the binary that lives in /usr/sbin. and edit
the .conf file in /private/etc/ntp-restrict.conf
Macs are quite a bit like BSD at that level.
Chris Albertson
Redondo Beach, California
On 13/06/2012, at 4:00 PM, Chris Albertson wrote:
On Wed, Jun 13, 2012 at 3:08 AM, Hal Murray hmurray@megapathdsl.net wrote:
Has anybody managed to get GPS NTP update working on OS-X?
Yes, All Macs come with NTP already installed. (Version 4.2.6) All
So Chris have you managed to get a GPS updating NTP as a peer on Mac OS X 10.7.4?
Linux Ubuntu 12.04 has NTP 4.2.6p3 and that works OK
you need to do is replace the binary that lives in /usr/sbin.
Replace with what?
and edit
the .conf file in /private/etc/ntp-restrict.conf
I have already edited both these conf files but still get:
key_expire: at 0 associd 7474
peer_clear: at 0 next 1 associd 7474 refid INIT
addto_syslog: refclock_open /dev/gps0: Operation not permitted <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<Just will not allow association as a peer. Permissions of devices and directories are all OK
addto_syslog: 127.127.20.0 interface 127.0.0.1 -> (null)
key_expire: at 0 associd 7475
peer_clear: at 0 next 2 associd 7475 refid INIT
event at 0 17.171.4.13 8011 81 mobilize assoc 7475
newpeer: 192.168.43.12->17.171.4.13 mode 3 vers 4 poll 6 10 flags 0x1 0x1 ttl 0 key 00000000
addto_syslog: DNS time.apple.com. ttl 3767
addto_syslog: DNS time.apple.com. minpoll 9
addto_syslog: DNS time.apple.com. maxpoll 12
addto_syslog: DNS time.apple.com. +iburst
key_expire: at 0 associd 7476
peer_clear: at 0 next 3 associd 7476 refid INIT
event at 0 17.83.253.7 8011 81 mobilize assoc 7476
newpeer: 192.168.43.12->17.83.253.7 mode 3 vers 4 poll 6 10 flags 0x1 0x1 ttl 0 key 00000000
addto_syslog: DNS time.asia.apple.com. ttl 3834
addto_syslog: DNS time.asia.apple.com. minpoll 9
addto_syslog: DNS time.asia.apple.com. maxpoll 12
addto_syslog: DNS time.asia.apple.com. +iburst
key_expire: at 0 associd 7477
peer_clear: at 0 next 4 associd 7477 refid INIT
event at 0 129.180.1.14 8011 81 mobilize assoc 7477
newpeer: 192.168.43.12->129.180.1.14 mode 3 vers 4 poll 6 10 flags 0x1 0x1 ttl 0 key 00000000
key_expire: at 0 associd 7478
peer_clear: at 0 next 5 associd 7478 refid INIT
event at 0 129.180.126.10 8011 81 mobilize assoc 7478
newpeer: 192.168.43.12->129.180.126.10 mode 3 vers 4 poll 6 10 flags 0x1 0x1 ttl 0 key 00000000
Macs are quite a bit like BSD at that level.
Chris Albertson
Redondo Beach, California
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