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Chapter 3: Communication Basics (Topics, Services, Actions)

Template

This is a template file. Fill in content from specs/001-physical-ai-book-specs/spec.md lines 357-452. Use Chapter 1 (01-introduction.mdx) as a formatting reference.

Chapter Purpose & Audience​

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Learning Objectives​

TODO: Add 3-6 learning objectives from spec.md lines 362-367

Prerequisites​

  • Completed Chapters 1-2
  • ROS 2 Humble installed and working
  • Basic understanding of nodes and topics

Key Concepts​

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  • Topics in depth
  • Services in depth
  • Actions in depth
  • QoS policies (reliability, durability, history)
  • Message types and interfaces
  • Creating custom messages

Topics (Publish-Subscribe)​

TODO: Add detailed topics section from spec.md

Creating a Publisher​

# TODO: Add Python publisher example

Creating a Subscriber​

# TODO: Add Python subscriber example

Services (Request-Response)​

TODO: Add services section from spec.md

Actions (Long-Running Tasks)​

TODO: Add actions section from spec.md

Diagrams / Architecture Notes​

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  • Topic Communication Flow
  • Service Call Sequence
  • Action Lifecycle Diagram

Practice Tasks​

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Summary​

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References​

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Next: Chapter 4: URDF for Humanoid Robots →