NAME

satpulsed - use a GPS receiver as an external clock source for PTP

SYNOPSIS

satpulsed [-h|--help] [-V|--version] [-v|--verbose] [-w|--wait]
    [-s|--systemd-log] [-f|--config-file path] [-d|--serial-device device-path]

DESCRIPTION

satpulsed enables a GPS receiver to be used as a source of time for the ptp4l PTP daemon, which allows ptp4l to work as a server (grandmaster) synchronized to time distributed by GPS. The PPS output of the GPS receiver must be connected to a Software Defined Pin (SDP) of an Ethernet controller with a PTP Hardware Clock (PHC) that supports external timestamping. There must also be a serial device connected to the GPS receiver. satpulsed synchronizes the PHC by reading messages from the serial device and timestamps from the external timestamping channel of the PHC. It also provides timing metadata to ptp4l using the PTP Management Protocol.

In addition, it

• can automatically configure a GPS receiver that uses the UBX protocol
• can work as a refclock for chronyd to enable a combined NTP/PTP time server
• can proxy the serial data to TCP (similarly to ser2net)
• provides a graphical web interface for monitoring the GPS receiver

satpulsed requires a configuration file in TOML.

The companion program satpulsetool(1) supports the use of satpulsed; in particular, it can be used to perform certain kinds of GPS configuration that are not done by satpulsed, such as configuration of baud rate and constellations/signals to be enabled.

satpulsed does not fork itself into the background. It should normally be run using systemd(1) as a Type=simple service. It needs root permissions so it can access the PHC.

OPTIONS

-h, --help

Show help.

-V, --version

Show version information.

-v, --verbose

Log more information.

-w, --wait

Wait for the network interface to be ready. This would typically be used in a systemd service file.

-s, --systemd-log

Log to standard output in a format suitable for systemd.

-f, --config-file path

Configuration file.

-d, --serial-device device-path

Serial device to use.

ENVIRONMENT

SATPULSE_CONFIG_FILE

Default configuration file path if -f option is not specified.

FILES

/etc/satpulse.toml

Conventional location of configuration file.

EXAMPLES

Start the daemon with the normal configuration file:

satpulsed -f /etc/satpulse.toml

Run in verbose mode with systemd logging:

satpulsed --systemd-log --wait -f /etc/satpulse.toml

SEE ALSO

satpulsetool(1), satpulsetool-gps(1), systemd(1), ptp4l(8), chronyd(8), ser2net(8)