Supported Sensors

Velodyne HDL-32E

velodyne-hdl32e
V2.0.0-b.1
Ethernet
70

Supported hardware versions

The driver interface communicates directly with the Velodyne HDL-32E LiDAR.

Manufacturer Velodyne
Hardware ID Velodyne HDL-32E
Firmware version(s) supported 2.2.21.0

Sensor background and requirements

The HDL-32E LiDAR sensor is small, lightweight, ruggedly built and features up to 32 lasers across a 40° vertical field of view. The HDL-32E measures only 5.7” high x 3.4” in diameter, weighs less than two kilograms and was designed to exceed the demands of the most challenging real-world autonomous navigation, 3D mobile mapping and other LiDAR applications.

Sensor Notes

To configure multiple HDL-32E sensors on the same machine or network, the UDP broadcast port on each sensor must be unique.

Hardware requirements

  • 12V power supply
  • Gigabit Ethernet connection to an ECU, or network switch
    • It’s strongly recommended to provide a direct connection from the LiDAR to the ECU
  • ECU with PolySync Core installed
  • Velodyne Interface Box

Configuring the sensor

  • Velodyne provides a web interface to configure and verify the sensor is powered and working
    • Enter the IP address of the sensor (default: 192.168.2.201) in the web browser URL
  • To configure multiple HDL-32E sensors on the same machine or network, the UDP broadcast port on each sensor must be unique along with the Telemetry Port
    • Under Network, edit the IP Address so that it is unique. Press the set button after you finish editing
    • Under Host, edit the telemetry port so that it is unqiue. Press the set button after you finish editing
    • Press the Save Configuration button
  • You will need to power cycle the sensor and PolySync Dynamic Driver to see changes

Configuring the ECU

Linux network set up

The Ethernet network must be properly configured before PolySync can communicate with the sensor on the target ECU.

It’s highly recommended to use point-to-point Ethernet communication between the sensor and the ECU to lower the latency. You may connect the sensor to a switch but may be prone to high latency.

Setting the ECUs static IP address

Once the LiDAR’s IP address is known, set a static IP address for the ECUs NIC in the same IP subnet range as the LiDAR.

For example if the LiDAR’s IP address is 192.168.2.201, it’s said to be on the 192.168.2 subnet, and the ECU should be configured with IP address 192.168.2.X.

Configuring the PolySync driver

The default PolySync Configurator configuration has shown to work out of the box on most systems.

Adding the sensor to the SDF

Using the Configurator tool, add a sensor node to the SDF.

The Velodyne HDL-32E ‘Node Interface’ name is velodyne-hdl-32e.

Validating the sensor is properly configured

If you’re approaching a new PolySync system or need to validate an existing configuration you can use the following check to ensure the sensor is properly configured.

Set up checklist

If the sensor passes this checklist then the PolySync dynamic driver will likely be able to communicate with the LiDAR sensor.

  1. Ensure you can ping the sensor at the static IP address
    • Get the IP address from the Configurator node entry, static IP address set in the preparing a sensor section
      • $ ping xxx.xxx.xxx.xxx
      • 64 bytes from xxx.xxx.xxx.xxx: icmp_seq=1 ttl=64 time=0.030 ms
      • ...
  2. Ensure you can access the Velodyne web interface through a web browser

Starting the PolySync driver

The configuration set in the Configurator is loaded from the SDF when the dynamic driver starts. It connects to the sensor through an Ethernet socket, requests the data, and waits for confirmation that the sensor configuration is valid.

When the dynamic driver receives the first packet of data, it begins processing and abstracting the data from the OEM data structure in a high-level hardware agnostic message type. In this case the LiDAR data is placed in a ps_lidar_points_msg.

  1. Power the sensor and ECU on
  2. Optionally follow the set up checklist
  3. Start the PolySync Core manager
    • $ sudo service polysync-core-manager start
  4. Start the dynamic driver process

Starting the node manually on the command line

To start a dynamic driver node on the command line, the node must first be defined in the SDF using the Configurator application.

Each node defined in the Configurator has a unique node ID which points to the nodes configuration. This article explains how to find the node ID.

Command line flags and usage

Once the node ID is known (substitute for X), the dynamic driver node for the supported sensor can be started with the base command:

$ polysync-core-dynamic-driver -n X

Each sensor supports an array of command line arguments. To see a full list of command line arguments, pass the -h help flag:

$ polysync-core-dynamic-driver -n X -h  |  less

There’s a lot of output so we recommend you pipe the output to less, but it’s not required.

Flag Required Description Arguments
-e No Export a JSON support string describing the interface, used by the SDF configuration tool N/A
-h No Show the help message N/A
-i <pal.so> No Use provided PAL interface file instead of what is stored in the SDF Path to the dyanmic driver interface PAL shared object library
-n <N> Yes SDF node configuration identifier for the node SDF node ID from the Configurator, [0-65536]
-o No Reserved N/A
-O No Check the node SDF configuration for required updates and exit option, returns exit status zero if no changes are required
-p <file.plog> No Use provided logfile in Record and Replay operations instead of the default File path to a PolySync plog logfile
-r <N> No SDF runtime configuration key that specifies the domain to operated under, the default domain is used otherwise Runtime configuration key, [0-65536]
-s <psync.sdf> No Use provided SDF instead of the default File path to an SDF file
-u No Allow updates to the SDF configuration during the normal runtime if needed (does not exit) N/A
-U No Update the node SDF configuration and exit N/A
-w No Disable the hardware interface(s), allowing the node to run without hardware connected - also known as replay mode N/A
DTC codes and common fixes
DTC value DTC name Fault description Notes
304 DTC_NOINTERFACE Interface not available Activated when the sensor is not reachable at the IP address set in the Configurator; activated when the sensor becomes unreachable during runtime

Accessing sensor data

When the dynamic driver node is operating in an OK state then data is being published to the global PolySync bus, and any node can subscribe to the high-level message type(s) output by the dynamic driver node.

There are several tools that PolySync provides to quickly validate that data exists on the bus.

Access sensor data with PolySync nodes that subscribe to the sensor’s output message types.

Input / output message types

The Velodyne HDL-32E dynamic driver node outputs the following message types to the bus.

Message API Docs Notes
Publishes pre-defined ‘ps_lidar_points_msg’ Sensor Data Model

It takes the following messages as inputs.

Message Notes
Native byte stream stored as ps_byte_stream_msg Ethernet: UDP socket\Default IP: 192.168.2.201\Default port: 2368

LiDAR points message fields

Data type Name Description Message field populated by this sensor
ps_msg_header header PolySync message header. Yes
ps_sensor_descriptor sensor_descriptor Sensor descriptor. Yes
ps_timestamp timestamp Scan start timestamp. [microseconds] Yes
ps_timestamp timestamp Scan end timestamp. [microseconds] Yes
ps_native_timestamp native_timestamp Native timestamp for the scan start. Provided by some devices. Check ps_native_timestamp.format for meaning. Format value PSYNC_NATIVE_TIMESTAMP_FORMAT_INVALID means not available. Yes
sequence <ps_lidar_point> points LiDAR points. Yes

Filtering incoming data for this sensor

An application that subscribes to a given message type is able to see data from more than one sensor or source.

Applications can filter for specific sensors and data sources in the message callback in C applications, or the messageEvent in C++ applications.

Filter incoming messages for this sensor with ps_sensor_kind value 70.

You can find all sensor descriptor values in this article.

Resources and configuration tools

This section has supporting resources and tools that are referenced throughout the article.

User Manual

Interface Box Manual

Velodyne HDL32E Software Version V2.0