TeamJ Wiki Entry on Lidar Setup Guide

_data/navigation.yml

@@ -138,6 +138,8 @@ wiki:
         url: /wiki/sensing/computer-vision-considerations/
       - title: Delphi ESR Radar
         url: /wiki/sensing/delphi-esr-radar/
+      - title: Velodyne VLP-16 LiDAR Setup Guide
+        url: /wiki/sensing/lidar-vlp16-setup/
       - title: Point Cloud Library, 3D Sensors and Applications
         url: /wiki/sensing/pcl/
       - title: Photometric Calibration

wiki/sensing/lidar-vlp16-setup.md

@@ -0,0 +1,334 @@
+---
+date: 2026-04-29
+title: Velodyne VLP-16 LiDAR Setup Guide
+---
+
+The Velodyne VLP-16 ("Puck") is a 16-channel 3D LiDAR widely used in robotics for mapping, localization, and obstacle detection. This tutorial covers the full setup on Ubuntu 24.04 with ROS 2 Jazzy — from hardware connection to point cloud visualization.
+
+## Hardware Requirements
+
+Before beginning, confirm you have the following:
+
+**Hardware:**
+- Velodyne VLP-16 Lidar
+- Velodyne interface cable (provides both power and Ethernet breakout)
+- DC power supply (check the voltage and current requirement on the VLP16 user manual)
+- A PC with a physical Ethernet port, or a USB-to-Ethernet adapter
+
+**Software (on host PC):**
+- Ubuntu 24.04
+- ROS 2 Jazzy (installation instructions at [docs.ros.org](https://docs.ros.org/en/jazzy/Installation.html))
+
+> **Note:** This guide is based on Ubuntu 24.04 and ROS 2 Jazzy. The general steps apply to other Ubuntu/ROS 2 combinations, but package names, file paths, and commands may differ slightly.
+
+---
+
+## Step 1: Physical Connection and Power-Up
+
+1. Connect the VLP-16's interface cable to your PC's Ethernet port (or USB-to-Ethernet adapter).
+2. Connect the power leads to your DC power supply.
+3. Power on the supply.
+
+Within a few seconds of power-up, the sensor should begin spinning. The status LEDs will be turned on once the sensor is operational. If the unit does **not** spin, double-check if the power source provides correct voltage level and supply current.
+
+---
+
+## Step 2: Configure a Static IP Address on Ubuntu
+All data is streamed over **UDP/IP Ethernet**. Check the sensor's default IP address in the user manual, and set your PC to a static IP on the same subnet to receive packets.
+
+The commands in the steps below use `192.168.1.201` as the lidar's IP and `192.168.1.100` as the PC's IP.
+
+
+### 2.1 Identify Your Ethernet Interface
+
+With the Ethernet cable **not yet connected** to the LiDAR, run:
+
+```bash
+ip a
+```
+
+Look for an interface name such as `enp0s31f6`, `eth0`, `eno1`, or (for USB adapters) something like `enx144fd7c114ac`. Note this name — we'll call it `<iface>` below.
+
+### 2.2 Assign a Temporary Static IP (Command Line)
+
+```bash
+sudo ip addr flush dev <iface>
+sudo ip addr add 192.168.1.100/24 dev <iface>
+sudo ip link set <iface> up
+```
+
+For example, if your interface is `enx144fd7c114ac`:
+
+```bash
+sudo ip addr flush dev enx144fd7c114ac
+sudo ip addr add 192.168.1.100/24 dev enx144fd7c114ac
+sudo ip link set enx144fd7c114ac up
+```
+
+Verify the address was applied:
+
+```bash
+ip a show <iface>
+```
+
+You should see `inet 192.168.1.100/24` in the output.
+
+### 2.3 (Optional) Make the Static IP Permanent
+
+The `ip addr` commands above are temporary — they will be lost after a reboot. If you want to persist the configuration, edit your Netplan configuration:
+
+```bash
+sudo nano /etc/netplan/01-netcfg.yaml
+```
+
+Add or modify the section for your interface:
+
+```yaml
+network:
+  version: 2
+  ethernets:
+    <iface>:
+      dhcp4: no
+      addresses:
+        - 192.168.1.100/24
+```
+
+Apply the configuration:
+
+```bash
+sudo netplan apply
+```
+
+---
+
+## Step 3: Verify the Network Connection
+
+Now **connect the Ethernet cable to the LiDAR** and ping the sensor's default IP:
+
+```bash
+ping 192.168.1.201
+```
+
+A successful response confirms network connectivity. If ping fails, check:
+- The Ethernet cable is seated in both the LiDAR interface box and the PC
+- The sensor is powered and spinning
+- Your IP was correctly assigned 
+
+
+### 3.1 Verify UDP Data Packets (No ROS Required)
+
+Even before installing any ROS packages, you can confirm the sensor is transmitting data using `tcpdump`:
+
+```bash
+sudo tcpdump -i <iface> udp port 2368
+```
+
+If the sensor is working, you will see a rapid flood of UDP packets. This step is highly recommended as it isolates hardware/network issues from ROS configuration issues. If `tcpdump` shows packets but ROS does not receive data, the problem is software-side. If `tcpdump` shows nothing, the problem is hardware or network.
+
+### 3.2 Access the Velodyne Web Interface
+
+The VLP-16 hosts a small configuration web page you can access from any browser:
+
+```
+http://192.168.1.201
+```
+
+From this page you can:
+- Change the sensor's IP address
+- Adjust the motor RPM (300–1200 RPM; lower RPM = denser point cloud per rotation)
+- Switch return mode: **Strongest**, **Last**, or **Dual** (dual doubles packet rate)
+- Update firmware
+
+> If you change the sensor IP here, remember to update your static IP assignment and all ROS launch configurations to match the new address.
+
+---
+
+## Step 4: Install the Velodyne ROS 2 Driver
+
+Install the Velodyne driver packages from the ROS 2 apt repository:
+
+```bash
+sudo apt update
+sudo apt install ros-$ROS_DISTRO$-velodyne*
+```
+
+This installs three packages:
+- `velodyne_driver` — reads raw UDP packets from the sensor and publishes `VelodyneScan` messages
+- `velodyne_pointcloud` — converts raw scans into standard `sensor_msgs/PointCloud2` messages
+- `velodyne_msgs` — message type definitions
+
+Source your ROS 2 environment (add to `~/.bashrc` if you haven't already):
+
+```bash
+source /opt/ros/$ROS_DISTRO$/setup.bash
+```
+
+---
+
+## Step 5: Launch the Driver and Verify Topics
+
+Launch all Velodyne nodes with the VLP-16 configuration:
+
+```bash
+ros2 launch velodyne velodyne-all-nodes-VLP16-launch.py
+```
+
+In a second terminal, list the active topics:
+
+```bash
+ros2 topic list
+```
+
+You should see at minimum:
+
+```
+/velodyne_packets
+/velodyne_points
+```
+
+Confirm data is flowing:
+
+```bash
+ros2 topic echo /velodyne_points --once
+```
+
+If you see a large block of point data printed to the terminal, your hardware and driver are fully functional.
+
+---
+
+## Step 6: Visualize Point Clouds in RViz2
+
+RViz2 is the standard 3D visualization tool bundled with ROS 2. It is the fastest way to inspect your point cloud data.
+
+Launch RViz2:
+
+```bash
+rviz2
+```
+
+In the RViz2 interface, configure the following:
+
+1. **Fixed Frame:** In the "Global Options" panel on the left, set the `Fixed Frame` to `velodyne`. This tells RViz2 to render everything relative to the LiDAR's own coordinate frame.
+
+2. **Add a PointCloud2 display:** Click the **Add** button at the bottom of the Displays panel, select **By topic**, and choose `/velodyne_points` of type `PointCloud2`.
+
+You should now see a live, rotating 360° ring of points around the sensor. Moving objects will update in real time. If you see a static or partial scan, check the rotation rate — at 300 RPM the update is slower but each scan is denser.
+
+---
+
+## Step 7: Visualize Point Clouds in Foxglove Studio
+
+[Foxglove Studio](https://foxglove.dev/) is a modern, web-based (and installable) visualization tool that works with ROS 2 and is particularly useful when you want a richer interface than RViz2, or when working with recorded bag files.
+
+### 7.1 Install Foxglove Studio
+
+Download the desktop application from [foxglove.dev/download](https://foxglove.dev/download), or use the web version at [studio.foxglove.dev](https://studio.foxglove.dev).
+
+Install the Foxglove bridge for ROS 2:
+
+```bash
+sudo apt install ros-$ROS_DISTRO$-foxglove-bridge
+```
+
+### 7.2 Launch the Bridge
+
+With your Velodyne driver already running in one terminal, open a second terminal and start the bridge:
+
+```bash
+source /opt/ros/$ROS_DISTRO$/setup.bash
+ros2 launch foxglove_bridge foxglove_bridge_launch.xml
+```
+
+By default, this exposes a WebSocket server on port `8765`.
+
+### 7.3 Connect and Visualize
+
+1. Open Foxglove Studio (desktop or browser).
+2. Click **Open connection** → **Rosbridge / Foxglove WebSocket**.
+3. Enter the address `ws://localhost:8765` (or replace `localhost` with your PC's IP if connecting from another machine on the network).
+4. Once connected, click the **+** button to add a **3D** panel.
+5. In the panel settings, add `/velodyne_points` as a topic. The point cloud will render in 3D immediately.
+
+Foxglove offers several advantages over RViz2 for data exploration: you can overlay multiple sensor streams, adjust color maps, and use the timeline scrubber when replaying bag files — all from a clean, browser-style interface.
+
+---
+
+## Step 8: Record and Replay Data with ROS 2 Bags
+
+Recording sensor data is essential for algorithm development and debugging, as it lets you replay exactly what the sensor captured during a real-world run.
+
+### 8.1 Record a Bag File
+
+Navigate to the directory where you want to store the bag, then run:
+
+```bash
+ros2 bag record /velodyne_points
+```
+
+This records the `/velodyne_points` topic. To record multiple topics simultaneously:
+
+```bash
+ros2 bag record /velodyne_points /velodyne_packets /tf
+```
+
+Press `Ctrl+C` to stop recording. The output will be a directory named:
+
+```
+rosbag2_YYYY_MM_DD-HH_MM_SS/
+```
+
+### 8.2 Replay a Bag File
+
+```bash
+ros2 bag play rosbag2_YYYY_MM_DD-HH_MM_SS
+```
+
+While the bag is playing, you can open RViz2 or Foxglove Studio exactly as described above — they will receive the replayed topic data just as if the physical sensor were connected.
+
+Useful replay options:
+
+```bash
+# Play at half speed (useful for slow-motion inspection)
+ros2 bag play rosbag2_YYYY_MM_DD-HH_MM_SS --rate 0.5
+
+# Loop the bag continuously
+ros2 bag play rosbag2_YYYY_MM_DD-HH_MM_SS --loop
+```
+
+### 8.3 Inspect Bag Contents
+
+```bash
+ros2 bag info rosbag2_YYYY_MM_DD-HH_MM_SS
+```
+
+This prints the recording duration, number of messages per topic, and storage format — useful for verifying a recording before sharing it.
+
+---
+
+
+## Summary
+
+This tutorial covered VLP-16 setup: hardware connection, static IP configuration, ROS 2 driver setup, and point cloud visualization. 
+
+## See Also
+- [Point Cloud Library (PCL), 3D Sensors and Applications](https://roboticsknowledgebase.com/wiki/sensing/pcl/)
+  — Next step after getting the sensor running: processing and filtering the point cloud data in your pipeline.
+- [Cartographer SLAM ROS Integration](https://roboticsknowledgebase.com/wiki/state-estimation/Cartographer-ROS-Integration/)
+  — A LiDAR-based SLAM algorithm that consumes `/velodyne_points` directly for map building and localization.
+- [ROS Mapping and Localization](https://roboticsknowledgebase.com/wiki/common-platforms/ros/ros-mapping-localization/)
+  — Overview of ROS mapping packages (gmapping, Hector Mapping) compatible with LiDAR data.
+- [ROS 2 Humble Intra-Process Communication Bag Recorder](https://roboticsknowledgebase.com/wiki/tools/ros2-humble-ipc-recorder/)
+  — Optimized bag recording for high-bandwidth sensors like LiDAR, reducing CPU overhead vs. standard `ros2 bag record`.
+- [Stream Rviz Visualizations as Images](https://roboticsknowledgebase.com/wiki/tools/stream-rviz/)
+  — How to stream your RViz2 point cloud view as an image topic, useful for remote monitoring or logging.
+
+## Further Reading
+- [Velodyne VLP-16 User Manual](https://ouster.com/downloads/velodyne-downloads)
+- [ROS 2 Velodyne Driver Documentation](https://docs.ros.org/en/jazzy/p/velodyne_driver/)
+- [Foxglove Studio Documentation](https://docs.foxglove.dev/)
+
+## References
+- Foxglove Technologies, "Foxglove Studio Documentation," foxglove.dev. [Online]. Available: https://docs.foxglove.dev/
+- Open Robotics, "ROS 2 Jazzy Jalisco Installation," docs.ros.org. [Online]. Available: https://docs.ros.org/en/jazzy/Installation.html
+- Open Robotics, "velodyne_driver — ROS 2 Jazzy," docs.ros.org. [Online]. Available: https://docs.ros.org/en/jazzy/p/velodyne_driver/
+- Velodyne Lidar, "VLP-16 User Manual," Ouster Inc. [Online]. Available: https://ouster.com/downloads/velodyne-downloads