# 如何使用Protobuf函数发送和接收消息 ## 1 介绍 ​ 假设有两台计算机，PC-A和PC-B，并且它们彼此相距很远。 将LiDAR与PC-A连接，由于某些原因，想在PC-B中使用点云消息。 此时，可能需要使用protobuf功能。 通常，有两种方法可以实现此目标。 - PC-A将雷达packet消息发送到PC-B。 PC-B收到雷达packet消息并对其进行解码，然后PC-B获得点云消息并使用它。 - PC-A解码雷达packet消息，获取点云并将点云消息发送到PC-B。 PC-B收到点云消息并直接使用。 rslidar_sdk提供这两种方式，但是通常建议使用第一种方法，因为点云消息非常大，对带宽有较高要求。 ## 2 通过Protobuf-UDP发送和接收 packets ​ 首先请阅读[参数简介](.. / intro / parameter_intro.md)，了解基本的参数配置。 ### 2.1 PC-A(发送端) ```yaml common: msg_source: 1 #0: not use Lidar #1: packet message comes from online Lidar #2: packet message comes from ROS or ROS2 #3: packet message comes from Pcap file #4: packet message comes from Protobuf-UDP #5: point cloud comes from Protobuf-UDP send_packet_ros: false #true: Send packets through ROS or ROS2(Used to record packet) send_point_cloud_ros: false #true: Send point cloud through ROS or ROS2 send_packet_proto: true #true: Send packets through Protobuf-UDP send_point_cloud_proto: false #true: Send point cloud through Protobuf-UDP pcap_path: /home/robosense/lidar.pcap #The path of pcap file ``` 由于数据来自在线LiDAR，因此请设置 *msg_source = 1* 。 通过protobuf-UDP发送雷达packet，因此设置 *send_packet_proto = true* 。 ```yaml lidar: - driver: lidar_type: RS128 #The lidar type - RS16, RS32, RSBP, RS128, RS80 frame_id: /rslidar #The frame id of message device_ip: 192.168.1.200 #The device ip address msop_port: 6699 #The msop port of lidar,default is 6699 difop_port: 7788 #The difop port of lidar, default is 7788 start_angle: 0 #The start angle of point cloud area end_angle: 360 #The end angle of point cloud area min_distance: 0.2 #The minimum distance of point cloud area max_distance: 200 #The maximum distance of point cloud area use_lidar_clock: false #true--Use the lidar clock as the message timestamp;false-- Use the system clock as the timestamp angle_path: /home/robosense/angle.csv #The path of the angle calibration file. For the latest version lidars, there is no need to use this file. ``` 检查雷达的 *msop_port，difop_port* 是否正确。 ```yaml proto: point_cloud_recv_port: 60021 #The port number used for receiving point cloud point_cloud_send_port: 60021 #The port number which the point cloud will be send to point_cloud_send_ip: 127.0.0.1 #The ip address which the point cloud will be send to msop_recv_port: 60022 #The port number used for receiving lidar msop packets difop_recv_port: 60023 #The port number used for receiving lidar difop packets msop_send_port: 60022 #The port number which the msop packets will be send to difop_send_port: 60023 #The port number which the difop packets will be send to packet_send_ip: 127.0.0.1 #The ip address which the lidar packets will be send to ``` 发送packet数据只需要关注三个参数，即 *msop_send_port，difop_send_port，packet_send_ip* 。 可以根据需要调整它们。 ### 2.2 PC-B(接收端) ```yaml common: msg_source: 4 #0: not use Lidar #1: packet message comes from online Lidar #2: packet message comes from ROS or ROS2 #3: packet message comes from Pcap file #4: packet message comes from Protobuf-UDP #5: point cloud comes from Protobuf-UDP send_packet_ros: false #true: Send packets through ROS or ROS2(Used to record packet) send_point_cloud_ros: true #true: Send point cloud through ROS or ROS2 send_packet_proto: false #true: Send packets through Protobuf-UDP send_point_cloud_proto: false #true: Send point cloud through Protobuf-UDP pcap_path: /home/robosense/lidar.pcap #The path of pcap file ``` 由于数据包消息来自protobuf-UDP，因此请设置 *msg_source = 4* 。 需要在ROS-Rviz上查看点云，因此设置 *send_point_cloud_ros = true* 。 ```yaml lidar: - driver: lidar_type: RS128 #The lidar type - RS16, RS32, RSBP, RS128, RS80 frame_id: /rslidar #The frame id of message device_ip: 192.168.1.200 #The device ip address msop_port: 6699 #The msop port of lidar,default is 6699 difop_port: 7788 #The difop port of lidar, default is 7788 start_angle: 0 #The start angle of point cloud area end_angle: 360 #The end angle of point cloud area min_distance: 0.2 #The minimum distance of point cloud area max_distance: 200 #The maximum distance of point cloud area use_lidar_clock: false #true--Use the lidar clock as the message timestamp;false-- Use the system clock as the timestamp angle_path: /home/robosense/angle.csv #The path of the angle calibration file. For the latest version lidars, there is no need to use this file. ``` 检查 *lidar_type* 是否正确。 ```yaml proto: point_cloud_recv_port: 60021 #The port number used for receiving point cloud point_cloud_send_port: 60021 #The port number which the point cloud will be send to point_cloud_send_ip: 127.0.0.1 #The ip address which the point cloud will be send to msop_recv_port: 60022 #The port number used for receiving lidar msop packets difop_recv_port: 60023 #The port number used for receiving lidar difop packets msop_send_port: 60022 #The port number which the msop packets will be send to difop_send_port: 60023 #The port number which the difop packets will be send to packet_send_ip: 127.0.0.1 #The ip address which the lidar packets will be send to ``` 接收packet数据只需要关注两个参数，即 *msop_recv_port，difop_recv_port* 。 必须确保它们与发送端中的 *msop_send_port，difop_send_port* 设置相同。 ## 3 通过Protobuf-UDP发送和接收点云 首先请阅读[参数简介](... / intro / parameter_intro.md)，了解基本的参数配置。 ### 3.1 PC-A(发送端) ```yaml common: msg_source: 1 #0: not use Lidar #1: packet message comes from online Lidar #2: packet message comes from ROS or ROS2 #3: packet message comes from Pcap file #4: packet message comes from Protobuf-UDP #5: point cloud comes from Protobuf-UDP send_packet_ros: false #true: Send packets through ROS or ROS2(Used to record packet) send_point_cloud_ros: false #true: Send point cloud through ROS or ROS2 send_packet_proto: false #true: Send packets through Protobuf-UDP send_point_cloud_proto: true #true: Send point cloud through Protobuf-UDP pcap_path: /home/robosense/lidar.pcap #The path of pcap file ``` 由于数据来自在线LiDAR，因此请设置 *msg_source = 1* 。 通过protobuf-UDP发送数据包，因此设置 *send_packet_proto = true* 。 ```yaml lidar: - driver: lidar_type: RS128 #The lidar type - RS16, RS32, RSBP, RS128, RS80 frame_id: /rslidar #The frame id of message device_ip: 192.168.1.200 #The device ip address msop_port: 6699 #The msop port of lidar,default is 6699 difop_port: 7788 #The difop port of lidar, default is 7788 start_angle: 0 #The start angle of point cloud area end_angle: 360 #The end angle of point cloud area min_distance: 0.2 #The minimum distance of point cloud area max_distance: 200 #The maximum distance of point cloud area use_lidar_clock: false #true--Use the lidar clock as the message timestamp;false-- Use the system clock as the timestamp angle_path: /home/robosense/angle.csv #The path of the angle calibration file. For the latest version lidars, there is no need to use this file. ``` 检查 *lidar_type,msop_port,difop_port* 是否正确。 ```yaml proto: point_cloud_recv_port: 60021 #The port number used for receiving point cloud point_cloud_send_port: 60021 #The port number which the point cloud will be send to point_cloud_send_ip: 127.0.0.1 #The ip address which the point cloud will be send to msop_recv_port: 60022 #The port number used for receiving lidar msop packets difop_recv_port: 60023 #The port number used for receiving lidar difop packets msop_send_port: 60022 #The port number which the msop packets will be send to difop_send_port: 60023 #The port number which the difop packets will be send to packet_send_ip: 127.0.0.1 #The ip address which the lidar packets will be send to ``` 发送点云只需要关注两个参数，即 *point_cloud_send_port, point_cloud_send_ip*。可以根据需要调整它们。 ### 3.2 PC-B(接收端) ```yaml common: msg_source: 5 #0--not use Lidar #1--packet message come from online lidar #2--packet message come from ROS or ROS2 #3--packet message come from Pcap file #4--packet message come from Protobuf-UDP #5--point cloud from Protobuf-UDP send_packet_ros: false #true--Send packets through ROS or ROS2(Used to record packet) send_point_cloud_ros: true #true--Send point cloud through ROS or ROS2 send_packet_proto: false #true--Send packets through Protobuf-UDP send_point_cloud_proto: false #true--Send point cloud through Protobuf-UDP pcap_path: /home/robosense/lidar.pcap #The path of pcap file ``` 由于点云消息来自protobuf-UDP，因此请设置 *msg_source = 5* 。 需要在ROS-Rviz上查看点云，因此设置 *send_point_cloud_ros = true* 。 ```yaml proto: point_cloud_recv_port: 60021 #The port number used for receiving point cloud point_cloud_send_port: 60021 #The port number which the point cloud will be send to point_cloud_send_ip: 127.0.0.1 #The ip address which the point cloud will be send to msop_recv_port: 60022 #The port number used for receiving lidar msop packets difop_recv_port: 60023 #The port number used for receiving lidar difop packets msop_send_port: 60022 #The port number which the msop packets will be send to difop_send_port: 60023 #The port number which the difop packets will be send to packet_send_ip: 127.0.0.1 #The ip address which the lidar packets will be send to ``` 接收点云只需要关注 *point_cloud_recv_port* 。 必须确保它与发送端中设置的 *point_cloud_send_port* 相同。