Esp32 simple speed message test of ros2 (limit frequency)

video ：

turtlesim_esp32 Release speed test

Use the following code , test ：

#include <ros2arduino.h>

#include <WiFi.h>
#include <WiFiUdp.h>


#define SSID       "***"
#define SSID_PW    "***"
#define AGENT_IP   "***"
#define AGENT_PORT *** //AGENT port number

#define PUBLISH_FREQUENCY 5000 //hz

void publishVel(geometry_msgs::Twist* vel, void* arg)
{
  (void)(arg);
  static int cnt = 0;
  vel->linear.x = 0.1+0.01*cnt;  // Linear velocity 
  vel->angular.z = 0.1+0.01*cnt; // angular velocity 
//  vel->linear.x = ((double)rand()/(RAND_MAX));  // Random linear velocity 
//  vel->angular.z = ((double)rand()/(RAND_MAX)); // Random angular velocity 
//  vel->linear.x = 0.2;                            // Fixed linear velocity 
//  vel->angular.z = 1.0 - 0.001*cnt;               // Changing angular velocity 
  cnt++;
}

class VelPub : public ros2::Node
{
public:
  VelPub()
  : Node("esp32_cmdvel")
  {
    ros2::Publisher<geometry_msgs::Twist>* publisher_ = this->createPublisher<geometry_msgs::Twist>("turtle1/cmd_vel");
    this->createWallFreq(PUBLISH_FREQUENCY, (ros2::CallbackFunc)publishVel, nullptr, publisher_);
  }
};

WiFiUDP udp;

void setup() 
{
  WiFi.begin(SSID, SSID_PW);
  while(WiFi.status() != WL_CONNECTED);

  ros2::init(&udp, AGENT_IP, AGENT_PORT);
}

void loop() 
{
  static VelPub VelNode;
  
  ros2::spin(&VelNode);
}

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The effect is as follows ：

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[email protected]:~$ ros2 topic -h
usage: ros2 topic [-h] [--include-hidden-topics]
                  Call `ros2 topic <command> -h` for more detailed usage. ...

Various topic related sub-commands

optional arguments:
  -h, --help            show this help message and exit
  --include-hidden-topics
                        Consider hidden topics as well

Commands:
  bw     Display bandwidth used by topic
  delay  Display delay of topic from timestamp in header
  echo   Output messages from a topic
  find   Output a list of available topics of a given type
  hz     Print the average publishing rate to screen
  info   Print information about a topic
  list   Output a list of available topics
  pub    Publish a message to a topic
  type   Print a topic's type

  Call `ros2 topic <command> -h` for more detailed usage.
 

[email protected]:~$ ros2 The theme -h
usage ：ros2 topic [-h] [--include-hidden-topics]
                    call `ros2 topic <command> -h` For more detailed usage . ...

Subcommands related to various topics

Optional parameters ：
   -h, --help Display this help message and exit
   --include-hidden-topics
                          Also consider hidden themes

command ：
   bw Shows the bandwidth used by the theme
   delay Show the delay of the topic from the timestamp in the title
   echo Output messages from a topic
   find Output a list of available topics of a given type
   hz Print the average release rate to the screen
   info Print information about the subject
   list Output a list of available topics
   pub Post a message to the subject
   type Type of print topic

    call `ros2 topic <command> -h` For more detailed usage .

---

[email protected]:~$ ros2 topic hz -h
usage: ros2 topic hz [-h] [--window WINDOW] [--filter EXPR] [--wall-time]
                     topic_name

Print the average publishing rate to screen

positional arguments:
  topic_name            Name of the ROS topic to listen to (e.g. '/chatter')

optional arguments:
  -h, --help            show this help message and exit
  --window WINDOW, -w WINDOW
                        window size, in # of messages, for calculating rate
                        (default: 10000)
  --filter EXPR         only measure messages matching the specified Python
                        expression
  --wall-time           calculates rate using wall time which can be helpful
                        when clock is not published during simulation
[email protected]:~$ 
 

[email protected]:~$ ros2 The theme hz -h
usage ：ros2 topic hz [-h] [--window WINDOW] [--filter EXPR] [--wall-time]
                      Subject name

Print the average release rate to the screen

Positional arguments ：
   topic_name To listen to ROS The name of the subject （ for example '/chatter'）

Optional parameters ：
   -h, --help Display this help message and exit
   --window window ,-w window
                          Window size , In the number of messages , Used to calculate the rate
                         （ The default value is ：10000）
   --filter EXPR Only measure to match the specified Python The news of
                          expression
   --wall-time Use wall time Calculation rate , It helps
                          When the clock is not released during simulation
[email protected]:~$

 

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