Implementing 802.11 with Microcontrollers: Wireless Networking for Embedded Systems Designers


  • Fred Eady, Systems Engineer, EDTP Electronics, FL, USA

Wireless networking is poised to have a massive impact on communications, and the 802.11 standard is to wireless networking what Ethernet is to wired networking. There are already over 50 million devices using the dominant IEEE 802.11 (essentially wireless Ethernet) standard, with astronomical growth predicted over the next 10 years. New applications are emerging every day, with wireless capability being embedded in everything from electric meters to hospital patient tracking systems to security devices.

This practical reference guides readers through the wireless technology forest, giving them the knowledge, the hardware and the software necessary to design a wireless embedded device rapidly, inexpensively, and effectively. Using off-the-shelf microcontrollers from Microchip and Atmel, the author provides step-by-step instructions for designing the hardware and firmware for a fully operational wireless networking device. The book gives a thorough introduction to 802.11 technology and puts it into perspective against the other wireless standard options. Just enough theory and mathematics is provided to give the depth of understanding needed for practical design work.

The book thoroughly covers:
* Laptop wireless Ethernet card introduction and theory
*Introduction to CompactFlash-to-microcontroller interfacing
* Implementing the laptop wireless Ethernet card in an embedded environment

In addition, the book includes access to a companion website containing all of the code, schematics and programs necessary to implement embedded 802.11 wireless networking.
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PRIMARY MARKET: Embedded systems engineers and programmers SECONDARY MARKET: Electrical/software engineering students, electronics technicians working in embedded systems, inhouse training departments of electronics manufacturers, electronics hobbyists


Book information

  • Published: September 2005
  • Imprint: NEWNES
  • ISBN: 978-0-7506-7865-0


“The world needs this book!” -Lewin Edwards, embedded engineer and author

Table of Contents

What’s on the companion website?

Chapter 1: Why Are We Doing This?
Selecting a Suitable Microcontroller
Selecting a Suitable 802.11b Communications Device
802.11b Hardware Overview
AirDrop Basics

Chapter 2: The AirDrop-P
The AirDrop-P Hardware
Learn to Play Guitar and Become Famous

Chapter 3: The AirDrop-A
The AirDrop-A Hardware
Bowing Out

Chapter 4: 802.11b CompactFlash Network Interface Cards
They Were Not Designed To Do This
The TEW-222CF
Never Ignore an Inquisitive Author with Hand Tools
Unwrapping the TEW-222CF
An Undercover Look at the Zonet ZCF1100
What’s Behind Door Number 4
RF, Witchcraft, Pointy Hats, Ghouls, Goblins…Same Thing

Chapter 5: Talking with 802.11bCompactFlash NICs
Physically Connecting a Microcontroller to a CompactFlash Card
Musical Overtones

Chapter 6: Touring the Card Information Structure
Talking in Tuples
First Steps with the AirDrop-P
Walking the Tuple Chain
CIS Reconnaissance
Dumping Linksys WCF12 Tuples
Dumping Netgear MA701 Tuples
Dumping Zonet ZCF100 Tuples
Enabling the 802.11b CompactFlash NIC
The Value of Parsing the CIS
Full Throttle

Chapter 7: Learning to Talk to 802.11b CompactFlash NICs
What the 802.11b NIC does for Us
The 802.11b CompactFlash NIC I/O Drivers

Chapter 8: Setting Up An AirDrop Wireless Network
Setting Up the AP
Something’s in the Air
Guitars and Hollywood

Chapter 9: AirDrop Driver Basics
Reading a RID
Stringing Up the SSID
Good RIDdance
Retrieving the MAC Address
Status Check

Chapter 10: Putting an AirDrop on a Wireless LAN
Bogie Number 1 - Allocating Transmit Buffers
Bogie Number 2 - Enabling the MAC
Authenticating the AirDrop Wireless LAN Station
Associating with the AIRDROP_NETWORK AP

Chapter 11: Processing 802.11b Frames with the AirDrop
AirDrop Frame Structure
AirDrop-P Frame Reception

Chapter 12: PINING the AirDrop
Examining the IP Header

Chapter 13: Flying Cargo with UDP and the AirDrop
Running a UDP Application on the AirDrop-P
The EDTP Internet Test Panel and the Code Behind It
Exercising the AirDrop-P with the EDTP Internet Test Panel

Chapter 14: Flying Cargo with TCP/IP and the AirDrop
TCP and the AirDrop-P
The TCP/IP Stack’s Physical Layer
The TCP/IP Stack’s Data Link Layer
The TCP/IP Stack’s Network Layer
The TCP/IP Stack’s Transport Layer
The TCP/IP Stack’s Application Layer
TCP/IP - The Big Ugly
You’ve Done It!

Chapter 15: WEP and the AirDrop
Incorporating WEP into the AirDrop 802.11b Driver
The New Experimental AirDrop Hardware
An Experimental AVR AirDrop Variant
The Experimental AirDrop Firmware
Coding a Simple 802.11b Web Server
The AirDrop SRAM

Chapter 16: A New Kid in Town Who Calls Himself ZigBee
Zig What???
Making ZigBee Talk
The Microchip ZigBee Stack

Chapter 17: Parting Frames
Numeric Notation
Source Code Presentation

Sub Snippets
Netasyst Sniffer Capture Text Presentation
Mini Sniffs