Everyday Practical Electronics, August 2011

WIN MICR A OC MPLA HIP Start B er Ki t

DELUXE 3-CHANNEL UHF ROLLING CODE REMOTE CONTROL High-security UHF transmitter/receiver for keyless entry, garage door or lighting control

SD CARD MUSIC & SPEECH RECORDER/PLAYER ‡ Free-standing recorder, or works ‡

with Windows, Mac or Linux PC Use as a jukebox or sound effects player

INPUT ATTENUATOR FOR THE DIGITAL AUDIO MILLIVOLTMETER An add-on project for measuring AC voltages to 140V RMS

PLUS

$8.99US

£4.25UK

AUGUST 2011 PRINTED IN THE UK

TEACH-IN 2011 – PART 10 Construction and testing AUGUST 2011 Cover v2.indd 1

27/06/2011 19:43:02

Microchip Offers Lowest Currents for Active and Sleep Modes

Microcontrollers

Low-Power Microcontrollers for Battery-Friendly Design

Digital Signal Controllers Analog Memory

Extend the battery life in your application using PIC® microcontrollers with nanoWatt XLP Technology and get the industry’s lowest currents for Active and Sleep modes. Microchip’s new peripheral-rich PIC12F182X, PIC16F182X and PIC16F19XX families offer active currents of less than 50 μA and sleep currents down to 20 nA. These products enable you to create battery-friendly designs that also incorporate capacitive touch sensing, LCD, communications and other functions which help differentiate your products in the marketplace. Microchip’s Enhanced Mid-range 8-bit architecture provides up to 50% increased performance and 14 new instructions that result in up to 40% better code execution over previous-generation 8-bit PIC16 MCUs. PIC12F182X and PIC16F182X families include: t Packages ranging from 8 to 64 pins t mTouch™ capacitive touch-sensing t Multiple communications peripherals t Dual I2C™/SPI interfaces t PWM outputs with independent time bases t Data signal modulator

PIC16F19XX family includes: t mTouch capacitive touch-sensing t LCD drive t Multiple communications peripherals t More PWM channels, with independent timers t Up to 28 KB of Flash program memory t Enhanced data EEPROM t 32-level bandgap reference t Three rail-to-rail input comparators

GET STARTED IN 3 EASY STEPS 1. View the Low Power Comparison videos 2. Download the Low Power Tips ‘n Tricks 3. Order samples and development tools www.microchip.com/XLP

PIC16F193X ‘F1’ Evaluation Platform - DM164130-1

Intelligent Electronics start with Microchip www.microchip.com/xlp The Microchip name and logo, the Microchip logo and PIC are registered trademarks and mTouch is a trademark of Microchip Technology Incorporated in the U.S.A. and other countries. © 2010 Energizer. Energizer and other marks are trademarks owned by Energizer. All other trademarks mentioned herein are property of their respective companies. © 2010, Microchip Technology Incorporated, All Rights Reserved. ME257Eng/06.10

MARCH 2011.indd 1

25/01/2011 13:48:18

ISSN 0262 3617 z PROJECTS z THEORY z z NEWS z COMMENT z z POPULAR FEATURES z VOL. 40. No 8

Aug 2011

INCORPORATING ELECTRONICS TODAY INTERNATIONAL

www.epemag.com

Projects and Circuits SD CARD MUSIC AND SPEECH RECORDER/PLAYER By Mauro Grassi Store WAV files on SD cards – standalone, or on any Windows, Mac or Linux PC

10

INPUT ATTENUATOR FOR THE DIGITAL AUDIO MILLIVOLTMETER by Jim Rowe Use our Digital Audio Millivoltmeter to measure AC voltages up to 140V RMS

26

DELUXE 3-CHANNEL UHF ROLLING CODE REMOTE CONTROL – PART 1 by John Clarke High-security UHF system for keyless entry, garage door control and external lighting

30

Series and Features TECHNO TALK by Mark Nelson The coming revolution

24

TEACH-IN 2011 by Mike and Richard Tooley Part 10: Electronic circuit construction and testing

42

PIC N’ MIX by Mike Hibbett MPLAB-X

56

CIRCUIT SURGERY by Ian Bell What’s all this noise about?

60

INTERFACE by Robert Penfold Long-lived converters

64

MAX’S COOL BEANS by Max The Magnificent Interesting times... Tornado warning...

68

NET WORK by Alan Winstanley Mobile content is king... 2D or not 2D…

74

Regulars and Services

© Wimborne Publishing Ltd 2011. Copyright in all drawings, photographs and articles published in EVERYDAY PRACTICAL ELECTRONICS is fully protected, and reproduction or imitations in whole or in part are expressly forbidden.

Our September 2011 issue will be published on Thursday 11 August 2011, see page 80 for details.

Everyday Practical Electronics, August 2011

Contents Aug 11.indd 1

EDITORIAL How safe are your digits?

7

NEWS – Barry Fox highlights technology’s leading edge Plus everyday news from the world of electronics

8

SUBSCRIBE TO EPE and save money

25

EPE BACK ISSUES CD-ROM Did you miss these?

40

MICROCHIP READER OFFER EPE Exclusive – Win a Microchip MPLAB Starter Kit For PIC24H MCUs

41

EPE BACK ISSUES Did you miss these?

59

CD-ROMS FOR ELECTRONICS A wide range of CD-ROMs for hobbyists, students and engineers

69

READOUT – Matt Pulzer addresses general points arising

72

DIRECT BOOK SERVICE A wide range of technical books available by mail order, plus more CD-ROMs

75

EPE PCB SERVICE PCBs for EPE projects

78

ADVERTISERS INDEX

79

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1

27/06/2011 14:52:14

Copyright © 2010, Wimborne Publishing Ltd (Sequoia House, 398a Ringwood Road, Ferndown, Dorset BH22 9AU, UK)

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