Cover.qxp 6/9/2008 8:34 AM Page 1 Photovoltaic Power Generation p. 22 • Coil Gun Launcher Project p. 38 • The “32-Bit Gate Crasher” p. 80 w w w . c i r c u i t c e l l a r . c o m CIRCUITTHE MAGAZINE FOR COMPUTER CELLAR APPLICATIONS #216 July 2008 INTERNET & CONNECTIVITY A Design For Delivering Targeted Web Site Content Do-It-Yourself Internet-Based Timekeeping Create A Modbus Slave For Data Intercommunication Decode & Transmit Magnetic Card Data Sound Effects Processing Made Easy Advanced Analog Design Techniques Electric Motor Theory Explained 07> 7925274 75349 $4.95 U.S. ($5.95 Canada) C2.qxp 3/3/2008 11:16 AM Page 1 SERIAL TO ETHERNET SOLUTIONS Simple Ethernet connectivity for serial devices Works out of the box - no programming is required Device P/N: SB70-100CR Customize to suit any Kit P/N: NNDK-SB70-KIT application with low-cost $69 SB70 development kit 2-port serial-to-Ethernet server Features: Qty. 100 with TTL support 10/100 Ethernet TCP/UDP mode DHCP/Static IP Support Data rates up to 921.6kbps Web-based configuration Need a custom solution? NetBurner Serial to Ethernet Development Kits are available Device P/N: SB72-EX-100CR to customize any aspect of Kit P/N: NNDK-SB72EX-KIT operation including web pages, data filtering, or custom network SB72EX $139 applications. All kits include 2-port serial-to-Ethernet server platform hardware, ANSI C/C++ Qty. 100 with RS-232 & RS-485/422 support compiler,TCP/IP stack, web server, e-mail protocols, RTOS, flash file system, Eclipse IDE, debugger, cables and power supply. Device P/N: PK70EX-232CR Information and Sales | [email protected] Kit P/N: NNDK-PK70EX232-KIT Web | www.netburner.com $269 PK70EX232 Telephone | 1-800-695-6828 4-port serial-to-Ethernet server Qty. 100 with RS-232 support 1.qxp 4/10/2008 12:50 PM Page 1 35.?AD?%$PDF !- 56-57.qxp 7/2/2007 10:52 AM Page 1 56-57.qxp 7/2/2007 10:52 AM Page 2 Task_Masthead_216.qxp 6/9/2008 8:51 AM Page 4 TASK MANAGER Energy Costs Drive Design Ingenuity FOUNDER/EDITORIAL DIRECTOR CHIEF FINANCIAL OFFICER Steve Ciarcia Jeannette Ciarcia ast July, I told you about my earliest experiences with the Internet. Since MANAGING EDITOR MEDIA CONSULTANT L C. J. Abate Dan Rodrigues the mid-1990s, my daily ’Net time has increased dramatically. Like most of you, I now use it for researching engineering topics, reading the news, fol- WEST COAST EDITOR CUSTOMER SERVICE Tom Cantrell Debbie Lavoie lowing stocks, interacting with friends and coworkers, ordering gifts, securing reservations, scheduling travel, and more. Hmm. I wonder what new ’Net- CONTRIBUTING EDITORS CONTROLLER Jeff Bachiochi Jeff Yanco related features I’ll be using in July 2009. Ingo Cyliax If gas prices continue to rise, I’ll probably be using the ’Net even more in an Robert Lacoste ART DIRECTOR KC Prescott effort to keep my monthly drive time to a minimum. I’ll increase my use of online George Martin Ed Nisley financial services rather than truck to the local bank branch (3.1 miles round GRAPHIC DESIGNERS Grace Chen trip) or investment consultant (21.74 miles round trip). I’ll watch movies on the NEW PRODUCTS EDITOR John Gorsky Carey Penney ’Net rather than drive to the nearest theater (7.28 miles round trip). I’ll buy more STAFF ENGINEER clothes online than offline at the local mall (14.24 miles round trip). I’ll order PROJECT EDITORS Gary Bodley John Gorsky wine from online distributors at bulk discount rates rather than hit the local Ken Davidson liquor shop (8.36 miles round trip). There are countless other examples. David Tweed Hopefully, by increasing my ’Net time and decreasing my drive time, I will ASSOCIATE EDITOR reduce my monthly cost of living, if only by a bit. At least the psychological Jesse Smolin effect of cost cutting should be more positive than negative. (Fingers crossed.) Trading in a four-wheeled shopping cart for a virtual shopping cart is only ADVERTISING one example of how average consumers are dealing with the price increas- 860.875.2199 • Fax: 860.871.0411 • www.circuitcellar.com/advertise es associated with rising energy costs. In the U.S., “hybrid” and solar tech- PUBLISHER nologies are all the rage (or at least conversations about them are). This Sean Donnelly Direct: 860.872.3064, Cell: 860.930.4326, E-mail: [email protected] augurs well for engineers, particularly the embedded designers and pro- grammers who read this magazine. In the coming months and years, you will ADVERTISING REPRESENTATIVE Shannon Barraclough use your ingenuity and design/programming prowess to develop the systems Direct: 860.872.3064, E-mail: [email protected] and programs that will advance these technologies—and you will be well ADVERTISING COORDINATOR paid for your services. Whether you design ’Net-connected systems that Valerie Luster enable remote access, build energy-efficient solar systems that cut monthly E-mail: [email protected] utility costs, or create advanced embedded systems for next-generation elec- tric vehicles, you will be improving the lives of countless consumers while Cover photography by Chris Rakoczy—Rakoczy Photography slowing the depletion of important natural resources. In this issue, we pres- www.rakoczyphoto.com ent articles about designs that can serve as starting points for such projects. PRINTED IN THE UNITED STATES If you’re interested ’Net-related technologies, turn to page 12, where DJ CONTACTS Delorie begins describing how he planned and designed an Internet-con- SUBSCRIPTIONS Information: www.circuitcellar.com/subscribe, E-mail: [email protected] nected alarm clock. The PIC-based design features automatic time setting, Subscribe: 800.269.6301, www.circuitcellar.com/subscribe, Circuit Cellar Subscriptions, P.O. Box 5650, Hanover, NH 03755-5650 streaming MP3 music, and remote management. Another handy Internet- Address Changes/Problems: E-mail: [email protected] connected design is Fernando Jordan’s SwissJazz system (p. 30). He uses GENERAL INFORMATION 860.875.2199, Fax: 860.871.0411, E-mail: [email protected] it to pull song title/artist information from an Internet radio station and display Editorial Office: Editor, Circuit Cellar, 4 Park St., Vernon, CT 06066, E-mail: [email protected] it without the use of a PC. You can build a similar system to gather and dis- New Products: New Products, Circuit Cellar, 4 Park St., Vernon, CT 06066, E-mail: [email protected] AUTHORIZED REPRINTS INFORMATION play the content of your choice. Although these two designs don’t directly 860.875.2199, E-mail: [email protected] AUTHORS reduce energy consumption, you can apply the basic design techniques to Authors’ e-mail addresses (when available) are included at the end of each article. other projects. Feature writers aren’t the only members of the Circuit Cellar community CIRCUIT CELLAR®, THE MAGAZINE FOR COMPUTER APPLICATIONS (ISSN 1528-0608) is published monthly by Circuit Cellar focused on tackling the problem of rising energy costs. Two of our columnists Incorporated, 4 Park Street, Vernon, CT 06066. Periodical rates paid at Vernon, CT and additional offices. One-year (12 issues) subscription rate USA and possessions $23.95, Canada/Mexico $34.95, all other countries $49.95.Two-year (24 issues) sub- have stepped up to the challenge. In the first part of a series titled “Living And scription rate USA and possessions $43.95, Canada/Mexico $59.95, all other countries $85. All subscription orders payable in U.S. funds only via Visa, MasterCard, international postal money order, or check drawn on U.S. bank. Direct subscription orders Working Off The Grid,” George Martin describes how he designed and and subscription-related questions to Circuit Cellar Subscriptions, P.O. Box 5650, Hanover, NH 03755-5650 or call installed a photovoltaic power-generating system at his New Mexico-based 800.269.6301. hideaway (p. 22). And finally, on page 74, Jeff Bachiochi examines electric Postmaster: Send address changes to Circuit Cellar, Circulation Dept., P.O. Box 5650, Hanover, NH 03755-5650. Circuit Cellar® makes no warranties and assumes no responsibility or liability of any kind for errors in these programs or schematics or for the motor technology. He covers electric motor theory, construction, and usage. consequences of any such errors. Furthermore, because of possible variation in the quality and condition of materials and workmanship of read- er-assembled projects, Circuit Cellar® disclaims any responsibility for the safe and proper function of reader-assembled projects based upon or from plans, descriptions, or information published by Circuit Cellar®. The information provided by Circuit Cellar® is for educational purposes. Circuit Cellar® makes no claims or warrants that readers have a right to [email protected] build things based upon these ideas under patent or other relevant intellectual property law in their jurisdiction, or that readers have a right to construct or operate any of the devices described herein under the relevant patent or other intellectual property law of the reader’s jurisdiction. The reader assumes any risk of infringement liability for constructing or operating such devices. We thank The National Institute of Standards and Technology for allowing us to use the Entire contents copyright © 2008 by Circuit Cellar, Incorporated. All rights reserved. Circuit Cellar is a registered trademark of Circuit Cellar, Inc. screenshot on the cover of this issue. For info about the NIST, visit www.nist.gov. Reproduction of this publication in whole or in part without written consent from Circuit Cellar Inc. is prohibited. 4 Issue 216 July 2008 CIRCUIT CELLAR® www.circuitcellar.com 5.qxp 6/5/2008 12:03 PM Page 1 USB Mixed Signal Oscilloscope Inventing the future requires a lot of test gear..