NTP Options
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This looks like something I need to have. If only because I can. ;)
I'm sure I remember reading what you were using for this Jim, can't find it now.
What are my options for hardware? Can I re-purpose an old phone perhaps with some software? Hacked sat-nav? I think I still have a Bluetooth GPS device somewhere here but I don't fancy trying to get that working!Steve
Edit: Not on the forum, it was in a tweet.
https://twitter.com/jimptwit/status/238006603826216961 -
I've got a USB serial GPS that it works with, though the unit is of slightly questionable quality as it seems to lock on to a GPS point about 25 miles away from where I actually am.
Anyhow, as it says on the page, anything that outputs the right signal (NMEA format output) on a serial port that the firewall can use is OK.
Some GPS units do that automatically, others need to be configured in their settings to output in the correct format.
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I am particularly liking the Google maps link. :) Checking for continental drift?
I guess for home use, which is where I would be deploying it, there is almost no need for 1ms accuracy in system time. What application might require this if you don't mind me asking?
As an aside I found it particularly ironic that this year, when daylight saving time ended, about the only piece of digital equipment I had to manually update was my sat-nav. ::) The one thing that absolutely definitely knows what time is and what time zone it's in!
Steve
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What application might require this if you don't mind me asking?
Steve
Public Safety Applications. Logging has to be on to the second, across the board with other agencies.
Even when the internet is down so generally we use GPS reference equipment.
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Also if you want to provide a highly accurate clock to your own users so that you don't need to rely solely on external time sources.
I'd say for more realtime applications like stock trading but IIRC USB is too slow/inaccurate for extremely high precision (e.g. PPS) to work properly. You'd need a "real" serial GPS unit for that.
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Are there any 2.0.2 snapshots. I've only seen the v2.1 snapshots.
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http://files.nyi.pfsense.org/jimp/foo/shiny/ehrmagerd/
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@jimp what device are you using? Cost of? I would love to do something like this.
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I forget the exact model, it was provided to me so I don't know the cost. It was going to be sold just for this type of deployment, but the quality of the devices wasn't quite what we'd hoped.
It still works passably for this for me, not sure how accurate it is in the long run though.
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You tweeted it much earlier Jim:
Navisys GR-601W USB GPS plugged into an ALIX. Nothing too fancy.
The problem with that particular device is that it doesn't seem to be available individually to the consumer.
Steve
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Aha, go figure twitter has a longer memory than me. ;-)
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Does anyone have suggestion of a device? I found this thread about that model
http://blog.gmane.org/gmane.comp.hardware.gps.thumbgps
Seems you can buy them in bulk 100 units ;)
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I've got a USB serial GPS that it works with, though the unit is of slightly questionable quality as it seems to lock on to a GPS point about 25 miles away from where I actually am.
Anyhow, as it says on the page, anything that outputs the right signal (NMEA format output) on a serial port that the firewall can use is OK.
The GPS unit is probably just fine.
The gps outputs the position in dd.mmmm (degrees,minutes(decimal minutes)). (ref. http://www.teletype.com/pages/support/Documentation/RMC_log_info.htm)
This data is sent to google maps, which expects the data in dd.dddd format. (degrees, decimal degrees.)You can use this calculator to convert the coordinate format: http://www.gpscoordinates.eu/convert-gps-coordinates.php
If you try, you should see that your gps actually works properly ;)
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Yep, you're right. I could swear I accounted for that in the code or used a special syntax in the google maps URL but I went back and checked again, and it didn't do the extra conversion.
Fixed now.. https://github.com/bsdperimeter/pfsense/commit/96a7ddb7604b4f422e2fdff3078e80109efed4dd
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The new link for the fix is at:
https://github.com/pfsense/pfsense/commit/96a7ddb7604b4f422e2fdff3078e80109efed4ddAlso the new patches are at:
http://files.nyi.pfsense.org/ -
This was fun to build and configure. Not as challenging as it could have been, though, if someone hadn't already compiled an image for the Pi: http://ntpi.openchaos.org/downloads/
Lots of useful info at this site, including the above link: http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html
Maybe one day I'll get around to putting it all in a box and mount the antenna where it has a better view of the sky. It's just sitting next to the window at the moment so the time is not that good - but always less than a second out (normally about 250-300ms).
1 x Adafruit Ultimate GPS Breakout - 66 channel w/10 Hz updates (Version 3) [ID:746] = $39.95
1 x Raspberry Pi Model B 512MB RAM[ID:998] = $39.95
1 x SMA to uFL/u.FL/IPX/IPEX RF Adapter Cable[ID:851] = $3.95
1 x GPS Antenna - External Active Antenna - 3-5V 28dB 5 Meter SMA[ID:960] = $12.95About $100 plus shipping.
My pfSense runs in a VM on the free version of ESXi, so there was no way to pass in the PPS signal on a serial port.
