Time

About This Module

The Time module provides the ability to start a Time sensor which will enable time synchronization for supported sensors.

Supported Time Sensors

Currently Time sensor is supported through Garmin 18X and Novatel GPS sensors.

Sensors available for time synchronization include:

• Velodyne lidar
• XSENS IMU/GPS
• Novatel IMU/GPS
• GMSL cameras

For a list of sensors supporting time synchronization through time sensor, see Sensor Timestamping

Start Time Sensor

To create a Time sensor, the DW module expects the following inputs:

• nvpps device
• reference type
• reference type specific start parameters
• optional PTP interface from additional network time domain

Supported Reference Types

Reference Type	Required Parameters	Example
NOVATEL_ETHERNET	ip, port	nvpps-device=/dev/nvpps0,reference-type=NOVATEL_ETHERNET,ip=192.168.0.210,port=2000
NOVATEL_CAN	can-device	nvpps-device=/dev/nvpps0,reference-type=NOVATEL_CAN,can-device=can0
NMEA	gps-serial-device, baud	nvpps-device=/dev/nvpps0,reference-type=NMEA,baud=9600,gps-serial-device=/dev/ttyUSB0
NONE

Note: Time reference type NONE will not log UTC time samples. Sensors dependant on UTC time synchronization will return host timestamps.

Starting Time Synchronization

To enable time synchronization for supported sensors, simply create and start the time sensor. The HAL will take care of synchronization. There are no further steps to access synchronized timestamps, which will automatically overwrite the original sensor frame/packet timestamps.

Playback from Recordings

The time module also supports time synchronization during playback using recorded time sensor data.

Relevant Tutorials

• Get Time Synchronized Data