Texas Instruments LMX9838 User Manual

LMX9838DONGLE Hardware User Guide

February 2007

Revision 0.3

1.0 Scope

National Semiconductor LMX9838 Bluetooth™ serial dongle reference design ki t is a plug and play serial a dap ter for serial cable replacement applications and more. It is able to support more profiles than just the Serial Port Profile (including audio support with external codec boards). By using the enclosed Simply Blue Commander software, it allows user to develop their own SW applications easily given the built in interpreter for HEX commands. SBSmart is a higher level application tool that provides buttons with the built in commands to easily set up or demonstrate different profile support using the Simply Blue SPP package.

2.0 General Description

2.1 REFERENCE DESIGN KIT CONTENTS

■ LMX9838 Bluetooth serial adapter reference board

■ USB Dongle and application software stack

■ Null modem cabl e

■ Sedona Lite board (Audio CODEC Board)

■ 110V to 240V AC to 5V DC power adapter and pigtail

■ CDROM with design documents and Simply Blue soft-

ware Application tools.

2.2 LMX9838 BLUETOOTH SERIAL ADAPTER REFERENCE BOARD

Figure 1. Reference Board and Sedona Lite Board

Bluetooth is a trademark of Bluetooth SIG, Inc. and is used under license by National Semiconductor.

3.0 Qualification

■ FCC certified: — FCC ID: ED9LMX9838

■ FCC compliance (see Section 13.0): The device com-

plies with Part 15 of FCC Rules. Operation is subject to the following two conditions:

— This device may not ca use harmful interference — This device must accept any interference received,

including interference that may cause undesired operation

■ IC certified: — IC: 1520A-LMX9838

■ Bluetooth SIG QD ID: B012394

4.0 Requirement and Setup

4.1 BASIC REQUIREMENT

LMX9838DONGLE Hardware User Guide

■ X86 PC with serial port.

■ One of the following operating system is required.

— Windows 2000 —Windows XP

4.2 APPLICATION SOFTWARE

4.2.1 Simply Blue Commander

Applicatio n com man d or ien ted t ool to ge ner ate comm ands and watch events in the Simply Blue Command interface window. Reference the Simply Blue Commander User Guide document for details.

4.2.2 SBSmart

Easy to use Windows based tool to demonstrate additional profile support of the Simply Blue functionality. Reference the SBSmart User Guide for additional details.

4.2.3 Patch Programming

LMX9838 allows for patch programming for firmware update if necessary. Reference the LMX9838 SW User Guide document for details. This can also be done with the Simply Blue Commander and SBSmart tools.

Figure 2. System Block Diagram

5.0 Functional Description

5.1 POWER SUPPLY

■ DC Power Jack (6V max)

■ Battery Holder (6V max)

5.2 MAIN SYSTEM

■ Reset button for manual Reset

■ Jumper option for Baud rate selection

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5.3 UART INTERFACE

DB9 connector for RS232 standard PC interface using Onboard level shifter IC for handling LMX9838 module’s 3.3V UART interface.

5.4 ADVANCE AUDIO INTERFACE

■ Support Audio applications

■ PCM codec interface (support linear and A-law)

■ PCM Master or Slave operation (SW configurable)

■ Direct connection to Sedona Lite Board (A-law only)

LMX9838DONGLE Hardware User Guide

6.0 Design Consideration

6.1 POWER MANAGEMENT

■ 3.3V output single LDO is used to provide power for

RS232 interface chi p and Digital porti on of the LMX983 8.

7.0 Layout Consideration

The LMX9838 reference design is split into 2 sections, one section is RS232 transceiver circuit for PC connection, another section is LMX9838 main circuit for Host processor. (Fig ure 3)

7.1 PCB REQUIREMENT

■ 2 layers PCB required

■ 1 mm overall thickness

7.2 LAYERS CLASSIFICATION

■ Top layer is the components and main signals layer

■ Bottom layer is interface signals and ground plane

■ RF circuit requirement

■ Large ground plane with ground via’s is must for good

RF performance

8.0 AUDIO CODEC Board

Table 2 Connectors Summary

Connector Description Details

J7 Battery Connector

2mm pitch J6 DC jack Same as above J8 DP9 serial connec-

tor (male) J5 External processor

interface J4 Advance Audio

interface

Table 3 Jumper and Test Point Summary

Jumper /

Test Point

J1, J2 and J3Clock & UART set-

Description Details

ting jumper

Maximum input voltage is 6V

See Table 5

See Table 6

See Table 7

See Table 8

Table 4 Switch and LEDs

Switch/LED Description

S1 Reset button D1 Operation Status D2 Data Traffic (TX/RX)

Sedona Lite Board c on t ai ns an audio codec a nd two phone jacks. This board can be used in conjuction with LMX9838DONGLE to realize the audio (SCO) transmission and reception capabilities. (See Table 9)

9.0 Board components and Pin Assignments

A summary of t he configuration and se lection jumpers is provided in the tables that follow. Reference both the schematic and PCB layout (included on the CD in the kit)

Table 1 Major Components List

Device Description

National LMX9838 Serial Port Module - Refer-

ence the device datasheet. National LP3985 Low-Dropout Voltage Regula-

tor Maxim MAX3225 1 Mbps High Speed UART

Driver

Table 5 J8 DP9 (male) Pin Assignments

Pin # Signal name Description

1 NC No connection 2 RxD Receive Data (inp ut) 3 TxD Transmit Data (output) 4 NC No connection 5 GND Ground 6 NC No connection 7 RTS Ready to send (output) 8 CTS Clear to send (input) 9 NC No connection

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