Dingo Bases

note

All topics in this file are namespaced with the appropriate OARBot namespace. For example dingo/cmd_vel becomes oarbot_blue/dingo/cmd_vel and oarbot_silver/dingo/cmd_vel respectively.

Input Topics

dingo/cmd_vel

Message type: geometry_msgs/msg/TwistStamped
Recommended publish rate: 20 Hz

By publishing to this topic, the dingo base will move/rotate in the direction specified.

Python

import rclpy
from rclpy.node import Node
from geometry_msgs.msg import TwistStamped

class CmdVelPython(Node):
    def __init__(self):
        super().__init__('cmd_vel_python')
        self.publisher_ = self.create_publisher(TwistStamped, '/oarbot_blue/dingo/cmd_vel', 1)

        # Create a timer to publish at 50ms (20 Hz) intervals
        self.timer = self.create_timer(0.05, self.timer_callback)
        self.get_logger().info("CmdVelPython Node initialized. Publishing velocity commands.")

    def timer_callback(self):
        msg = TwistStamped()
        msg.header.frame_id = "base_link"
        msg.header.stamp = self.get_clock().now().to_msg()

        # Set linear X velocity (e.g., moving forward at 0.5 m/s)
        msg.twist.linear.x = 0.5

        self.publisher_.publish(msg)
        self.get_logger().info('Publishing velocity command to /oarbot_blue/dingo/cmd_vel')


def main(args=None):
    rclpy.init(args=args)
    node = CmdVelPython()
    rclpy.spin(node)

    node.destroy_node()
    rclpy.shutdown()


if __name__ == '__main__':
    main()

C++

#include <cstdlib>
#include <chrono>

#include "geometry_msgs/msg/twist_stamped.hpp"
#include "rclcpp/rclcpp.hpp"

class CmdVelCpp : public rclcpp::Node
{
public:
    CmdVelCpp() : Node("cmd_vel_cpp")
    {
        cmd_vel_publisher = this->create_publisher<geometry_msgs::msg::TwistStamped>("/oarbot_blue/dingo/cmd_vel", 1);

        this->timer = create_wall_timer(std::chrono::milliseconds(50), [this]() -> void {
            geometry_msgs::msg::TwistStamped msg = geometry_msgs::msg::TwistStamped();
            msg.header.frame_id = "base_link";
            msg.header.stamp = this->get_clock()->now();
            msg.twist.linear.x = 0.5;
    
            RCLCPP_INFO(this->get_logger(), "Publishing to /oarbot_blue/dingo/cmd_vel");
            this->cmd_vel_publisher->publish(msg);
        });
    }
    
private:
    rclcpp::Publisher<geometry_msgs::msg::TwistStamped>::SharedPtr cmd_vel_publisher;
    rclcpp::TimerBase::SharedPtr timer;
};


int main(int argc, char **argv)
{
    rclcpp::init(argc, argv);
    rclcpp::spin(std::make_shared<CmdVelCpp>());

    rclcpp::shutdown();
    return EXIT_SUCCESS;
}

dingo/emergency_stop

Output Topics