# Velodyne 相關紀錄與議題

## Connect to VLP-16 by ethenet

### 預設連接方式

1. 先點網路連線的符號
2. 編輯連線
3. 新增有線網路
4. 選擇裝置下拉，點選連接 VLP-16 的網卡MAC
5. 點選 IPv4 設定IP 改成手動
6. 新增地址： 192.168.1.77
7. 確定即新增完畢
8. 斷線再點選啟動新連線
9. Browser 打 192.168.1.201 即可進入

   **tips:如果LiDAR IP是192.168.0.1(範例),則電腦IP也需要設為192.168.0.X**

### **硬體設定注意事項**

![VLP-16 setting page](/files/-LXOJcHR8Z3fHxnQOm69)

Host IP Address 要對齊到電腦的網卡IP , 同時必須設定在跟Sensor **同網域之下 (192.168."0".X)**

Sensor 的 IP 可以隨意設定，但是Gateway 也要在**同網域之下**

### Velodyne 尋找連接 IP

1. 安裝 wireshark  `sudo apt-get install wireshark`
2. 啟用 wireshark，看封包資訊
3. 尋找封包資訊指定的目標 IP

## Velodyne 節點意義

參考資料： Ros wiki package: Velodyne (<http://wiki.ros.org/velodyne_pointcloud>)

### CloudNodelet

Subscribed Topics:   **velodyne\_packets(velodyne\_msgs/VelodyneScan)**

Published Topics: **velodyne\_points(sensor\_msgs/PointCloud2)**

## Subcriber vs Publisher 議題

### CMakeList.txt

#### ISSUE: undefined reference to \`pcl::console::print(pcl::console::VERBOSITY\_LEVEL, char const\*, ...)

```bash
# solution:
target_link_libraries(subSensorPC2_to_pubPCLPCXYZI ${PCL_LIBRARIES} ${catkin_LIBRARIES})
# 需要把 ${PCL_LIBRARIES} 放在最前面
```

#### 啟動 lidTopPub

```bash
roslaunch velodyne_pointclound hino_front_vlp32c.launch
rosrun lidar_grabber_hino lidTopPub
rosrun display_hino display_hino   #宗賢a視覺化
rosrun rviz rviz -f 
```

## Velodyne MAKE ISSUE

#### ISSUE:  No Package Call yaml-cpp, pcl-ros, tf, angles, jsk\_recognition-msgs....

```bash
#solution: install Velodyne code dependencies
sudo apt-get install -y libyaml-cpp-dev ros-kinetic-pcl-ros ros-kinetic-pcl-conversions ros-kinetic-angles ros-kinetic-tf ros-kinetic-diagnostic-updater ros-kinetic-jsk-recognition-msgs
```

#### ISSSUE: Can't Find PCL

```bash
#edit CMakeList and add below line.
# /opt/pcl/1.9.0/share/pcl-1.9/ should be the pcl installed path.
set(PCL_DIR "/opt/pcl/1.9.0/share/pcl-1.9/")
```

**ISSUE: /usr/lib/gcc/aarch64-linux-gnu/5/../../../aarch64-linux-gnu/libGL.so: undefined reference to \`drmGetDevices2' ....**

**ref:** [**https://devtalk.nvidia.com/default/topic/1044109/jetson-agx-xavier/no-usr-lib-aarch64-linux-gnu-tegra-libgl-so-0-with-jetpack-4-4-1/**](https://devtalk.nvidia.com/default/topic/1044109/jetson-agx-xavier/no-usr-lib-aarch64-linux-gnu-tegra-libgl-so-0-with-jetpack-4-4-1/)

```bash
#not sure now
sudo rm /usr/lib/aarch64-linux-gnu/libdrm.so.2
sudo -H ln -s /usr/lib/aarch64-linux-gnu/libdrm.so /usr/lib/aarch64-linux-gnu/libdrm.so.2
```


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