Bluetooth

Architecture and Applications

Chris Greco, Wesley Kunzler, Koy Rehme, Zhuo Ruan

Bluetooth Stack

Bluetooth Radio (Link Layer)

• 2.4 GHz• 79 channels

– 1 MHz spacing– 23 channels in some

countries

• Gaussian Frequency Shift Keying

• RSSI (Receiver Signal Strength Indicator)

Baseband (Physical Layer)

• Pseudorandom hopping sequence• Synchronous Connection-Oriented (SCO)

– Audio

• Asynchronous Connection-Less (ACL)– Data

• Error Correction– 1/3 rate FEC– 2/3 rate FEC– ARQ scheme

Baseband (Physical Layer)

• Connection Modes: Active, Sniff, Hold, Park• Device Addressing

– Bluetooth Device Address (48 bits)– Active Member Address (3 bits)– Parked Member Address (8 bits)– Access Request Address

• Synchronization requires:– Channel hopping sequence– Phase– Channel Access Code

Link Manager Protocol (LMP)

• Manages connections and pairings• Authentication• Pairing• Key change• Encryption• Detaching• Power Control• … and much more!

Host Controller Interface (HCI)

Host Controller Interface (HCI)

• Hardware Status and Registers

• Bluetooth-specific commands

• Flow Control

• Error Recovery

• Transport Layers (RS-232, UART, USB)

Logical Link Control and Application Protocol (L2CAP)

• Designed only for ACL links (i.e. no Audio)• Segmentation and Reassembly• Quality of Service• Piconet operation

RFCOMM

• Emulates RS-232 over L2CAP protocol

• Accommodates types 1 and 2 devices

• Supports up to 60 emulated serial ports

• Does not suffer from low-power mode latency delays

• Serial-Bluetooth adapters available– Easily convert to wireless

• Allows for internet-type services

Service Discovery Protocol (SDP)

• Determine which services are available and their characteristics (services)– Universally Unique Identifiers (UUIDs)– Searching for services– Browsing for services

• List of capabilities sent during pairing

• Baby monitor

• Wristwatch communicator – 007 style

• Serial port extender

• PDA Chat

• Audio extender (speaker in other room)

• Indoor/outdoor thermometer / home weather station

• Palatometer

Socket Corp.

(a) (b)

Socket’s CF Ruggedized Serial I/O Card with high-speed serial drivers

Accessory hardware including power adapter, null modem adapter Software tools including Socket’s Bluetooth 1.1 Certified Stack for Windows CE devices

NOTE: Socket’s Bluetooth Stack Dev Tools allow developers to write applications that are Bluetooth aware. These Tools provide built-in screens for doing device discovery and pairing.

$5000

BlueGiga WT11 BT Module

• Bluetooth® Class 1• Two antenna options: internal chip antenna or U.FL

connector• Up to 2-3Mbps • USB version 2.0 compliant• UART with bypass mode • 8Mb of flash memory• RoHS compliant• Control with ASCII commands, or GPIO, or UART

$53Serial or USB interface

$625

Expected shipping date: 01/26/07

Bluepacket 2037 Module

• Arm7 processor

• Class 1

• Firmware embedded

• Integrated MP3 decode

• No answer when called

(a) (b)

BTEVAL:

(Bluetooth evaluation board)

Build-in RS232, TTL converter

ICD2 programming socket

24C256 Memory

Price: $179

Toothpic DARC-I:

(Remotely Configurable Data Acquisition and Remote Control Module)

Tooth PIC module, Serial data I/O

PWM-digital/parallel output control

Analog/digital/parallel input control

Capture of frames of input data up to 5K samples / sec

Price: $64.70

READY Intl Corp.

READY Intl Corp.

(c)

Toothpick DARC-II (Data Acquire& Remote Control with User Interface Server)

Developer interface tools

1. Bluetooth application development

2. On-line analyzer for running remote devices

3. Price: $474

Make Bluetooth Work for You: Build a

Sample Chat Application

• Visual Studio .NET 2003 Final Beta

• Two Pocket PCs with Bluetooth

• Microsoft ActiveSync 3.6

• Prices: $400~500

Rabbit Semiconductor BT Kit

• Comes with 30 MHz uC

• Serial UART control – up to 115kbps

• Complete with sample applications and source code

• $340

Avnet DS-KIT-P160-COMM3

• Xilinx FPGA on board (Microblaze)

• Flash, SRAM, ADC, DAC, Ethernet

• “Easy to use Bluetooth module” (921 kbps UART interface)

$225