If you need a source for time and don't have regular internet for your node(s), you can use a GPS dongle to get good enough results. This is NOT a high accuracy NTP 'stratum 1' option, but should be 'good enough' to milliseconds for your mesh.
First, you need to have a raspberry pi or other linux based computer with a base install, and a GPS that is compatible with pi/linux.
Install some packages to get gps and ntp functionality.
Then, tweak the gpsd and ntp configs to use GPS dongle.
0. Give your pi a static mesh IP assignment on the mesh
1. install required packages on pi (internet needed):
sudo apt-get install libgps gpsd gpsd-clients ntp
2. remove internet and reconnect pi to mesh as needed
3. on pi, edit /etc/default/gpsd, add/modify this line:
GPSD_OPTIONS="-n"
4. reboot pi
5. on pi, run cgps command line program and check output for gps lock
6. if cgps/gpsd does not work or use correct device, specify gps device in /etc/default/gpsd, and reboot. In my experience, gpsd 'just works'.
7. on pi, edit /etc/ntp.conf
1. comment out "pool..." lines
2. add this at bottom of file:
# GPSD
server 127.127.28.0 prefer
fudge 127.127.28.0 flag1 1 refid GPS
8. on pi, restart ntp (/etc/init.d/ntp restart)
9. on pi, check with command line program ntpq -p. You should see some output regarding 'GPS'. 'Offset' should be 'small'
10. on pi, check time is accurate with 'date' command
11. on another mesh computer, check ntpd availability with windows command line on computer connected to mesh: w32tm /stripchart /computer:[your_pi.local.mesh]
12. configure nodes to use pi for network time. The ntp server entry on main config page at bottom = [your_pi.local.mesh]
13. nodes should have proper time within 0-15 minutes if the pi is accessible on the mesh
14. profit
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easy GPS NTP server howto
Tue, 08/13/2019 - 13:43
#1
easy GPS NTP server howto
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Should the package "libgps" actually be "libgps-dev"?
https://centerclick.com/ntp
I have the NTP200 and it works great - and it is Stratum 1.
If you want to see mine, feel free to look at: http://k6ccc.org:12380
That's a look only page, so you can't break anything.
Note about step 12. If you advertise the NTP service properly, no additional configuration is required in order for nodes on the AREDN mesh to get time from it - other than having a firmware version released some time this year (I don't remember which build added that). As of the last I looked, there are 169 AREDN devices that have made a NTP request from my NTP200.
https://docs.arednmesh.org/en/latest/arednGettingStarted/basic_setup.htm...
Hi Jim,
That's some nice kit. Good to see you're using the u-blox MAX-M8 - that keeps my paychecks coming ;-). Have a look at the MAX-M10. Drop in and more available.
I got one of those SparkFun surprise boxes over the summer and an old, but working, RPi 1 model B was in there. I figured that could handle serving NTP easy enough ;-). Something to play with and learn, so I don't mind the erector set approach.
When setting up a go box, I'll certainly consider one of your CenterClick units.
Cheers & 73,
Bob / N8SQT
You can get them at https://shop.airframes.io/collections/network-servers in case you feel like supporting Airframes in the process (though he's got them on Amazon and direct too).