912  Bluetooth Fundamentals and Architecture

912.1 Overview

Bluetooth is one of the most ubiquitous wireless technologies in IoT, powering everything from fitness trackers and smart locks to industrial sensors and building automation systems. This chapter series provides a comprehensive guide to Bluetooth technology, covering both Classic Bluetooth and Bluetooth Low Energy (BLE).

TipFor Beginners: What is Bluetooth?

Think of Bluetooth like a wireless conversation between two devices that are close together. Just like how you can talk to a friend standing next to you without needing a phone line, Bluetooth lets devices “talk” to each other without wires.

Two types of Bluetooth:

  • Classic Bluetooth: Like a phone call—good for long conversations (music streaming)
  • BLE (Bluetooth Low Energy): Like text messages—quick updates, then the device goes back to sleep (fitness trackers, sensors)

912.2 Chapter Series

This comprehensive topic has been organized into focused chapters for easier learning:

912.2.1 Core Concepts

Chapter Description Reading Time
Classic Bluetooth vs BLE Evolution, differences, power consumption 15 min
Bluetooth Topologies Star, broadcast, mesh configurations 12 min
Piconet Architecture Central/peripheral roles, 7-device limit 10 min
Connection Establishment Discovery, pairing, bonding 15 min
Protocol Stack GATT architecture, notifications 12 min
Bluetooth Profiles SPP, HID, A2DP, HFP 10 min

912.2.2 Hands-On Learning

Chapter Description Time
Hands-On Lab Build BLE sensor beacon (Wokwi) 30 min

912.3 Quick Comparison

Aspect Classic Bluetooth BLE
Purpose Audio streaming, files Sensors, beacons
Power Medium (mA) Very low (uA)
Battery Life Days-weeks Months-years
Data Rate 1-3 Mbps 125k-2M bps
Best For Headphones, speakers Fitness trackers, locks

912.4 Learning Paths

NoteRecommended Reading Order

Quick Start (1 hour):

  1. Classic vs BLE - Understand the difference
  2. Hands-On Lab - Build something

Full Coverage (3+ hours):

  1. Classic vs BLE
  2. Topologies
  3. Piconet Architecture
  4. Connection Establishment
  5. Protocol Stack
  6. Profiles
  7. Hands-On Lab

912.5 Key Takeaways

  • BLE is not backward compatible with Classic Bluetooth—separate protocols
  • Power optimization requires understanding advertising intervals and connection parameters
  • GATT is the foundation of BLE data exchange (services, characteristics)
  • Bluetooth Mesh extends BLE to building-scale with up to 32,000 nodes
  • Profile selection depends on use case (audio, sensors, input devices)

912.6 What’s Next

Start with Classic Bluetooth vs BLE to understand the fundamental differences, or jump to the Hands-On Lab for immediate practical experience.

Deep Dives:

Comparisons: