MAVLink入门教程09.03:通过UDP发送数据至QGC

系列索引:MAVLink入门教程索引

目的

本文介绍如何通过UDP直接发送数据给QGC的Mavlink框架中。

MavSDK

先从MAVSDK下载静态库。

只能使用VS2022编译运行

心跳包

MavSDK初始化

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auto component_type = Mavsdk::ComponentType::Autopilot;//1
auto config = Mavsdk::Configuration(component_type);//2
auto mav = Mavsdk(config);//3
std::cout << "Mavsdk version: " << mav.version() << std::endl;
std::cout << "Sys ID: " << unsigned(config.get_system_id()) // use unsigned for uin8_t
<< ", Component ID: " << unsigned(config.get_component_id())
<< ", Always heartbeats: " << config.get_always_send_heartbeats()
<< std::endl;

Mavsdk定义了一个Mavsdk类,需要先将这个类实例化后再使用。

主要语句就是这个第3行。config是Configuration类的一个实例,对应第一行代码。Autopilot是mavsdk中已经定义好的枚举类型,也可以指定其他类型。

运行输出为

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[05:02:30|Info ] MAVSDK version: v2.10.0 (D:\a\MAVSDK\MAVSDK\src\mavsdk\core\mavsdk_impl.cpp:26)
Mavsdk version: v2.10.0
Sys ID: 1, Component ID: 1, Always heartbeats: 1

UDP

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// Use my own udp library
auto udp = UdpCom();
int r = udp.Open("127.0.0.1", 14540, "127.0.0.1", 14550);
std::cout << "UDP Open: " << r << std::endl;

打开本地的14540/14550端口,这个是QGC/Mavlink默认端口

心跳包

根据流程创建心跳包并填充数据

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// Heartbeat message
mavlink_message_t msg_heartbeat;
uint8_t len_heartbeat;
uint8_t buf_heartbeat[MAVLINK_MAX_PACKET_LEN];
mavlink_msg_heartbeat_pack(config.get_system_id(), config.get_component_id(), &msg_heartbeat,
MAV_TYPE_QUADROTOR, MAV_AUTOPILOT_GENERIC, MAV_MODE_GUIDED_ARMED, 0, MAV_STATE_ACTIVE);
len_heartbeat = mavlink_msg_to_send_buffer(buf_heartbeat, &msg_heartbeat);

无论是串口还是udp,最后发送的都是字节码buf_heartbeat而不是msg_heartbeat结构体。

发送

以1Hz的频率发送

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// Whenever a second has passed, we send a message.
while (true)
{
current_time = time(NULL);
if (current_time - last_time >= 1) {
udp.Send((char*)(buf_heartbeat), len_heartbeat);
std::cout << "Heartbeat sent." << std::endl;

last_time = current_time;
}
}

效果

编译运行程序。

打开QGC

QGC

先打开数据发送程序,后打开QGC,此时QGC是连接状态

点击左上角打开工具

工具

选择应用设置

应用设置

点击MAVLink Inspector标签,自动显示接收的数据

MAVLink Inspector

频率为1Hz,数据类型,数据值都有显示。

Vibration(震动)

根据心跳包的创建流程创建震动数据包

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// Vibration message
mavlink_message_t msg_vibration;
uint8_t len_vibration;
uint8_t buf_vibration[MAVLINK_MAX_PACKET_LEN];
uint64_t time_usec=1000;
float vx = 25;
float vy = 50;
float vz = 100;
uint32_t c0=1;
uint32_t c1=2;
uint32_t c2=3;
mavlink_msg_vibration_pack(config.get_system_id(), config.get_component_id(), &msg_vibration,
time_usec, vx, vy, vz, c0, c1, c2);
len_vibration = mavlink_msg_to_send_buffer(buf_vibration, &msg_vibration);

通过UDP发送数据。

查看Analyze Tools -> Vibration界面

震动

数据开始发送后

接收数据

完整代码

库文件

此部分是VS工程设置

VS编译设置为C++17标准

C++17标准

头文件

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$(SolutionDir)mavsdk\include;

库文件

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$(SolutionDir)/mavsdk/lib;
ws2_32.lib;mavsdk.lib;

UDP

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/*****************************************************************
* @file samll_udp.h
* @brief A very simple header-only library for udp communication in Windows.
*
* @author zswzy
* @date 20230529
*********************************************************************/

#ifndef SUDP_HPP
#define SUDP_HPP

#include <stdio.h>
#include <string>
#include <WS2tcpip.h>

#pragma comment (lib, "ws2_32.lib")

class UdpCom {
private:
SOCKET m_in;
sockaddr_in m_local;
const char* m_local_ip;
int m_local_port;
int m_local_length;
sockaddr_in m_dest;
const char* m_dest_ip;
int m_dest_port;
int m_dest_length;
char m_buffer[4096];
public:
/**
* @brief The UDP class constructor.
*
* @return
*/
UdpCom()
{
m_in = NULL;
m_local = sockaddr_in();
m_local_length = sizeof(m_local);
m_local_ip = "127.0.0.1";
m_local_port = 0;
m_dest = sockaddr_in();
m_dest_length = sizeof(m_dest);
m_dest_ip = "0.0.0.0";
m_dest_port = 0;
memset(m_buffer, 0, sizeof(m_buffer));
ZeroMemory(&m_dest, sizeof(m_dest));
}

/**
* @brief destructor.
*
*/
~UdpCom()
{Close();}

/**
* @brief Open UDP.
* @return 0: normal, 1: Winsock error, 2: bind error.
*/
int Open()
{
int return_code = 0;
// Startup Winsock 开启winsock
WSADATA data;
WORD version = MAKEWORD(2, 2);
int wsOK = WSAStartup(version, &data);
if (wsOK != 0) {
printf("can't start Winsock. Error: %d.\n", wsOK);
return_code = 1;
}
// Bind socket 绑定本地端口号
m_in = socket(AF_INET, SOCK_DGRAM, 0);
m_local.sin_family = AF_INET;
m_local.sin_port = htons(m_local_port); // Convert from little to big endian
inet_pton(AF_INET, m_local_ip, &m_local.sin_addr);
// 检测是否成功绑定
if (bind(m_in, (sockaddr*)&m_local, sizeof(m_local)) == SOCKET_ERROR)
{
printf("Can't bind socket! Error: %d.\n", WSAGetLastError());
return_code = 2;
}
// 绑定远端
m_dest.sin_family = AF_INET;
inet_pton(AF_INET, m_dest_ip, &m_dest.sin_addr);
m_dest.sin_port = htons(m_dest_port);
printf("UDP is open.\n");
return return_code;
}

/**
* @brief Open UDP with parameters.
*
* @param local_ip local IPv4 address.
* @param local_port local port.
* @param dest_ip remote IPv4 address.
* @param dest_port remote port.
* @return
*/
int Open(const char* local_ip, const int local_port, const char* dest_ip, const int dest_port)
{
SetLocal(local_ip, local_port);
SetDest(dest_ip, dest_port);
Open();
return 0;
}

/**
* @brief Receive message from remote.
*
* @return
*/
int Receive()
{
ZeroMemory(m_buffer, 4096);
// 接收消息,储存为变量buf,类型为字符串
int byte_in = recvfrom(m_in, m_buffer, 4096, 0, (sockaddr*)&m_dest, &m_dest_length);

if (byte_in == SOCKET_ERROR)
{
printf("Error receiving from client. Error code: %d", WSAGetLastError());
}
printf("%s \n",m_buffer);
//recv_data = jsonxx::json::parse(m_buffer);
return 0;
}

/**
* @brief Send message to remote.
*
* @param message_send
* @return 0: normal, 1: Error.
*/
int Send(char* message_send, int len)
{
int return_code = 0;
//printf("message_send: %s, sizeof: %d\n", message_send, strlen(message_send));
int send_ok = sendto(m_in, message_send, len, 0, (sockaddr*)&m_dest, sizeof(m_dest));
if (send_ok == SOCKET_ERROR)
{
printf("Send error.\n");
return_code = 1;
}
else
{
// std::cout << "Send OK" << std::endl;
}

return return_code;
}

/**
* @brief Close UDP. It is called in the destructor.
*
* @return
*/
int Close()
{
// Close socket
closesocket(m_in);
// Shutdown winsock
WSACleanup();
return 0;
}

/**
* @brief Set remote parameters: IP and port.
*
* @param dest_ip remote IPv4 address.
* @param dest_port remote port.
* @return
*/
int SetDest(const char* dest_ip, const int dest_port)
{
m_dest_ip = dest_ip;
m_dest_port = dest_port;
return 0;
}

/**
* @brief Set local parameters: IP and port.
*
* @param local_ip local IPv4 address.
* @param local_port local port
* @return
*/
int SetLocal(const char* local_ip, const int local_port)
{
m_local_ip = local_ip;
m_local_port = local_port;
return 0;
}

/**
* @brief Get received message.
*
* @return
*/
char* GetContent()
{
return m_buffer;
}
};

#endif // SUDP_HPP

main

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// System
#include <iostream>
#include <time.h>

// Project header
#include "sudp.hpp"

// MAVSDK
#include "mavsdk/mavsdk.h"

using namespace mavsdk;

int main()
{
auto component_type = Mavsdk::ComponentType::Autopilot;
auto config = Mavsdk::Configuration(component_type);
auto mav = Mavsdk(config);
std::cout << "Mavsdk version: " << mav.version() << std::endl;
std::cout << "Sys ID: " << unsigned(config.get_system_id()) // use unsigned for uin8_t
<< ", Component ID: " << unsigned(config.get_component_id())
<< ", Always heartbeats: " << config.get_always_send_heartbeats()
<< std::endl;

// Use my own udp library
auto udp = UdpCom();
int r = udp.Open("127.0.0.1", 14540, "127.0.0.1", 14550);
std::cout << "UDP Open: " << r << std::endl;

// Timing
static time_t last_time = 0;
time_t start_time = time(NULL);
time_t current_time = time(NULL);

// Heartbeat message
mavlink_message_t msg_heartbeat;
uint8_t len_heartbeat;
uint8_t buf_heartbeat[MAVLINK_MAX_PACKET_LEN];
mavlink_msg_heartbeat_pack(config.get_system_id(), config.get_component_id(), &msg_heartbeat,
MAV_TYPE_QUADROTOR, MAV_AUTOPILOT_GENERIC, MAV_MODE_GUIDED_ARMED, 0, MAV_STATE_ACTIVE);
len_heartbeat = mavlink_msg_to_send_buffer(buf_heartbeat, &msg_heartbeat);

// Vibration message
mavlink_message_t msg_vibration;
uint8_t len_vibration;
uint8_t buf_vibration[MAVLINK_MAX_PACKET_LEN];
uint64_t time_usec=1000;
float vx = 25;
float vy = 50;
float vz = 100;
uint32_t c0=1;
uint32_t c1=2;
uint32_t c2=3;
mavlink_msg_vibration_pack(config.get_system_id(), config.get_component_id(), &msg_vibration,
time_usec, vx, vy, vz, c0, c1, c2);
len_vibration = mavlink_msg_to_send_buffer(buf_vibration, &msg_vibration);

// Whenever a second has passed, we send a message.
while (true)
{
current_time = time(NULL);
if (current_time - last_time >= 1) {
udp.Send((char*)(buf_heartbeat), len_heartbeat);
std::cout << "Heartbeat sent." << std::endl;

udp.Send((char*)(buf_vibration), len_vibration);
std::cout << "Vibration sent." << std::endl;

last_time = current_time;
}
}

return 0;
}

MAVLink入门教程09.03:通过UDP发送数据至QGC
https://feater.top/mavlink/send-data-to-qgc-with-udp/
作者
JackeyLea
发布于
2024年6月15日
许可协议