DRAWS™: Setup NTP Timeserver Using Chrony

We recommend using chrony instead of ntpd.  This NTP server can use the GPSD server to synchronize the Raspberry Pi time to the satellites and also supports connections to other NTP servers should the GPS loose the satellites.

Install and Run Chrony 

GPSD should be running.

Make sure you have chrony installed, by issuing the following command

sudo apt-get update && sudo apt-get install chrony

This will install chrony and create an initialization file in /etc/chrony/chrony.conf which will need to be edited.

At a minimum, add the following two lines:

refclock SHM 0 refid GPS precision 1e-3 offset 0.5 delay 0.2 poll 3 trust require
refclock SHM 2 refid PPS precision 1e-9 poll 3 trust

Assuming you are connected to a LAN and want to have other systems see and/or poll for time, you can add the following (Example uses a LAN with addresses in the range 192.168.1.0 - 192.168.1.255)

broadcast 30 192.168.1.255
allow 192.168.1.0/24

Save the file and execute:
sudo systemctl enable chrony && sudo systemctl restart chrony && systemctl status chrony

This should show chrony in an active running state and it will be set to automatically restart after a reboot.

Verify Chrony is Running

Run the program:
chronyc sources

More Information

For more configuration information, execute the command:
man chrony.conf