Why It’s So Hard to Start with ROS 2 (And How to Actually Overcome It)

You’ve built a robot. Maybe you used a simple Arduino or Raspberry Pi to make it move and sense its environment. It worked. You felt great. Now you’re ready to level up and enter the world of ROS 2 for beginners—the Robot Operating System. But very quickly, that excitement turns to confusion.

You’re not just writing code anymore. You’re wrestling with colcon, ament_cmake, mysterious CMakeLists.txt files, launch files, nodes, and topics—and the terminal looks like it belongs to another planet. Your working robot becomes a chaotic mess. You’re not alone. This is the point where most beginners give up.

But you don’t have to.

The Real Reason ROS 2 Feels Hard for Beginners

For ROS 2 for Beginners, the difficulty isn’t about intelligence—it’s about scope. Starting with ROS 2 feels overwhelming because you’re climbing five different learning curves at once. Let’s break them down:

The Five Mountains of ROS 2

1. A New Programming Language in a New Paradigm

You might be familiar with Arduino’s loop() structure, but now you’re staring at callback-based, asynchronous Python or C++ using the rclpy or rclcpp libraries. You’re also dealing with pointers, shared memory, and topics.

2. A Complex Build System

You move from clicking “Upload” in Arduino to hand-writing CMakeLists.txt files and managing dependencies with ament_cmake. Most beginners have never heard of CMake, let alone debugged linker errors.

3. A Distributed Communication Architecture

In ROS 2, everything is decentralized. You must understand how nodes publish and subscribe to topics, how services and actions work, and how all of these components communicate over a DDS network.

4. A Command-Line-Heavy Ecosystem

For ROS 2 for Beginners, the system assumes you’re already comfortable using the terminal. Sourcing workspaces, launching nodes, echoing topics, and troubleshooting all happen via the CLI.

5. The Actual Robotics Problem

All this complexity is layered on top of your original problem: controlling a robot, reading sensors, and making decisions.

The Solution: Climb One Mountain at a Time – Understand the ROS2 Package Structure First

Instead of tackling everything at once, break it into manageable steps. Here’s how to conquer ROS 2 the right way.

Step 1: Conquer the C++ and Build System Mountain First

Learn C++ the ROS Way (But Without ROS Yet)

Before even thinking about ROS, write some C++ code that teaches you:

#include <iostream>

using namespace std;

int main() {

    cout << "Hello, ROS World!" << endl;

    return 0;

}

Start with simple, single-file programs. Then, graduate to multi-file projects with header files.

Build with CMake

Here’s a basic CMakeLists.txt to get you started:

cmake_minimum_required(VERSION 3.10)

project(hello_ros)

add_executable(main src/main.cpp)

Learn how to:

• Build a project with cmake and make
• Link against your own libraries
• Separate interface (.hpp) and implementation (.cpp)

Mastering CMake will remove 90% of the fear associated with ROS 2 packages later.

Step 2: Understand ROS 2 Without Hardware

Use the ROS 2 Turtlesim to experiment with nodes, topics, and services.

ros2 run turtlesim turtlesim_node

Then publish a command:

ros2 topic pub /turtle1/cmd_vel geometry_msgs/Twist "{linear: {x: 2.0}, angular: {z: 1.8}}"

This sandbox lets you:

• Visualize data flow with rqt_graph
• Echo topics with ros2 topic echo
• List active nodes with ros2 node list

ROS 2 for Beginners: Create a talker node and a listener node to simulate real-world communication. You’ll learn:

• How to structure a ROS 2 workspace
• How nodes communicate in real time
• How to debug message flow using the CLI

Step 3: Your First Real ROS 2 Robot Project (Using ROS2 Package Structure)

Now that you understand the structure, build a real robot. But avoid the mistake of doing it all at once.

Build Without ROS First

Use an ESP32, ultrasonic sensor, and basic DC motors with an L298N driver. Write a simple Arduino sketch:

void loop() {

  float distance = readUltrasonic();

  if (distance < 20.0) {

    stop();

    turnLeft();

  } else {

    goForward();

  }

}

Confirm all hardware works independently. This isolates hardware bugs from software issues.

Design the ROS 2 Architecture on Paper

Before you code anything in ROS, answer these questions:

• What are the nodes? (e.g., Sensor Node, Logic Node, Motor Node)
• What topics do they use? (e.g., /ultrasonic_distance, /cmd_vel)
• How does the ESP32 connect to ROS? (via micro-ROS)

graph LR

ESP32_Sensor[ESP32 Sensor Node] -->|/ultrasonic_distance| Logic_Node[PC Logic Node]

Logic_Node -->|/cmd_vel| ESP32_Motor[ESP32 Motor Node]

Implement in Stages

Start the micro-ROS Agent:

ros2 run micro_ros_agent micro_ros_agent udp4 --port 8888

Then, verify topic communication:

ros2 topic echo /ultrasonic_distance

Write your ROS 2 logic node in Python:

import rclpy

from rclpy.node import Node

from std_msgs.msg import Float32

from geometry_msgs.msg import Twist

class ObstacleAvoider(Node):

    def __init__(self):

        super().__init__('obstacle_avoider')

        self.sub = self.create_subscription(Float32, '/ultrasonic_distance', self.callback, 10)

        self.pub = self.create_publisher(Twist, '/cmd_vel', 10)

    def callback(self, msg):

        twist = Twist()

        if msg.data < 0.2:

            twist.linear.x = 0.0

            twist.angular.z = 1.0

        else:

            twist.linear.x = 0.2

            twist.angular.z = 0.0

        self.pub.publish(twist)

rclpy.init()

rclpy.spin(ObstacleAvoider())

rclpy.shutdown()

This closes the loop: sensor ➝ logic ➝ motors.

Add Visualization with RViz

ROS 2 isn’t just for code—it’s also for debugging and visual feedback.

Create a simple visualization_node that publishes a marker to RViz:

from visualization_msgs.msg import Marker

# Setup omitted for brevity

Open RViz:

rviz2

Add a Marker display. Watch as obstacles appear in your 3D scene.

Final Thoughts: You Built a Real ROS 2 System

By taking a strategic, layered approach, you’ve learned to:

• Write modular C++ code
• Use CMake confidently
• Understand ROS 2’s node/topic system
• Control hardware with ROS 2
• Visualize data with RViz

You didn’t just make a robot turn away from a wall. You built a distributed ROS 2 architecture a foundational step in ROS 2 for beginner learning. That system can now scale to navigation, SLAM, object recognition, and more.

To deepen your understanding of how ROS 2 works across real robotic systems, you can also explore the official ROS 2 documentation—a reliable, high-authority resource maintained by Open Robotics.

If you’re serious about learning practical, hands-on robotics with ROS 2, our Mobile Robotics Engineering Course is built for beginners like you. From hardware to SLAM to deployment—we walk you through it all.