Everything for Electronics

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January 2004

Nuts and Volts Magazine


Features

DIGITAL CONTROL WITHOUT PROGRAMMING

Closed-loop controllers make automatic adjustments to maintain constant output despite varying conditions. Examples include supply voltage, fluid temperature, motor speed, and light intensity. These parameters would shift over time and load without consistent correction.


BOOK REVIEW: HAM RADIOS FOR DUMMIES

Starting out in ham radio can be fun, but — as with any high tech hobby — there are plenty of hurdles to overcome. Ward Silver’s new book, Ham Radio for Dummies, published by Wiley, offers a well-written and friendly guide to starting and growing your new hobby...


BOOK REVIEW: THE DIGITAL CONSUMERS TECHNOLOGY HANDBOOK

On April 3, 2000, when President Clinton’s Justice Department issued its ruling that Microsoft had violated US antitrust laws and the NASDAQ plummeted 349 points (or 7.64%) — its worst single-day performance ever — it signaled the end of the Internet bubble. The next year, the horrific terrorist attacks on the US occurred on September 11th. As a result, we’ve seen much less of what Tom Wolfe once dubbed the “digibabble and fairy dust” that ruled the 1990s...


NEW LIFE FOR LORAN - PART 2

This month, we will continue with the story of the retirement of the world's most powerful vacuum tube LORAN transmitter of 1.6 megawatts at the US Coast Guard station at George, WA. The vacuum tube transmitter went on air in September of 1976 and was officially taken off air on December 8, 2003. After switching the antenna transmission line from the vacuum tube transmitter, a new solid-state transmitter was operating within about two hours. Read on to learn about the new solid-state concept...


NEW LIFE FOR LORAN - PART 1

It’s not very often that a guy gets to witness “the changing of the guard” during his lifetime, but I’ve been fortunate enough to do just that. As the years have gone by, we’ve all seen technology change in unimaginable ways that stun us with “gee whiz” events. December 8, 2003 marked the beginning of the end in an era of vacuum tube LORAN “C” (LOng RAnge Navigation) transmitters.


A WHITE LED NIGHT LIGHT

I discovered LEDs back in 1974, and thought they were the coolest thing ever. I was still in high school at the time and I was just starting to play with TTL. While others my age were out partying and chasing girls, I was getting my jollies by watching red LEDs count in binary. That’s probably why I didn’t have a lot of friends.


PICAXE(S)

Yes — an irksome PIC trade off between cost and programming difficulties has existed. Bare PICs — such as the popular PIC16F84 (itself now obsolete) — are cheap and powerful, but too complicated for many enthusiasts and educators.


ROY NORMAN: FROM THE A-BOMB TO THE ENTERPRISE

It served him well with the US Navy; by 1948, he had already served for seven years. He was stationed in Guam, working his way up to the rank of petty officer first class, “getting rid of electronics equipment by throwing it over a cliff,” when he got his orders to report to Sandia Base in Albuquerque, NM.


SELECT AN INEXPENSIVE LOGIC ANALYZER

“You can tell the difference between a professional and an amateur by the tools they use,” or so the saying goes, but even pros have a limited budget. So, you only buy the tools as you need them. Sometimes, you only need a tool for a short period of time or just for one project. So, when you need a specialty tool, do you rent, borrow, or buy? If you need a full set of features, it might be cheaper to lease the equipment. Alternatively, you might want to buy an inexpensive device if it satisfies


DSP

The inspiration for this idea came from my students. Teaching DSP is difficult because you must slog through a fair amount of math before getting useful results. I noticed that, during my lecture on Z transforms, most students had donned their Walkmans/MP3 players. Their eyes were rolling. I needed drastic measures to turn this around. So, why not use the students’ love of music as a tool for teaching DSP? (Yes, I loved the movie The School of Rock.)


Working with Digital Filters

Most of the books and technical papers that describe digital filtering consist mostly of complex mathematical concepts with little to no emphasis placed on the practical implementation of a physical digital filter. The math behind digital filtering techniques is indeed interesting, but you don’t have to be a mathematician to design and build a working digital filter. Keep reading and I’ll prove it to you.


A TRULY SOLDERLESS BREADBOARD - PART 2

Last month, I showed you how easy it is to build logic circuits using a Xilinx CPLD (Complex Programmable Logic Device). This month, we'll dig into a more sophisticated design. In particular, I'll show you how to build a useful piece of test equipment — a "logic scope." This is a poor man's logic analyzer. The logic scope reads four bits of digital data, records them, and then displays the waveforms on a normal oscilloscope.


PICK THE NETWORK PROTOCOL THAT’S RIGHT FOR YOUR DEVICE

If you have a device that you want to use in a local network or on the Internet, one of the decisions you’ll need to make is how the device will exchange information with other computers in the network. Many devices host web pages that display information and enable users to send input, but web pages aren’t the only option.


UNIVERSAL SERIAL BUS

USB is the answer to the development of all the new external peripherals for the PC platform. USB is low cost, fast, easy to use, bi-directional, and capable of real time data transfer of voice, audio, and video. Currently, USB 2.0 has a bandwidth of 480 Mbps, which is 40 times greater than the previous version — USB 1.1 — with a fully compatible bandwidth of 12 Mbps.


Shakey — A 1960’s Predecessor to Today’s Advanced Robotics

in Micro Memories

All technology has to begin somewhere and there’s a direct link between Shakey and the mobile robots of today.


Harvesting Electricity From The Environment

Light a 100 Volt Bulb with the Waves that Surround You


CONTROL YOUR DEVICES FROM A WEBPAGE

Of all of the millions of pages on the web, most are hosted by large servers or, at minimum, desktop PCs, but these aren't the only computers that can function as web servers. Even very small devices can serve web pages on request, including pages that display real-time information and respond to user input. The pages can either be available within a local network or an Internet connection can be added to make the pages available to anyone on the Internet.


The New Electronics Experimenter

Electronics as a hobby is not going away as some have thought, it has just changed — BIG TIME!


Microcontrollers Are Great — But Don’t Pass Up Conventional Electronics

Not every application needs a microcontroller, yet often times they're used in a project unnecessarily. I’ll show you two examples of circuits that don't use a micro, but are often built with one, and explain some of the logic and theory behind these circuits.


Bipolar Transistor Cookbook — Part 7

Practical transistor audio power amplifier and 'accessory' circuits. Part 7 of 8


Good PCB Design

Designing a circuit board for ease of manufacturing can help insure your project stays on schedule and the redo's are left for someone else.


The Man Who Invented The Future

Hugo Gernsback was the world’s first futurist — one who not only speculated about the future, but also worked to make it happen.


Bipolar Transistor Cookbook — Part 8

A miscellaneous collection of useful transistor circuits and gadgets in this final episode. Part 8 of 8


The Colossus of Radio

Crosley Radio Corporation’s 1936 “WLW Model Super-Power Radio Receiver”


Learn About Cyclic Redundancy Checks

CRC Detects Errors in Digital Data Communications and Can Encrypt Data


The Transistor Radio

In 1954, the world was a far different place than it is now. Almost anything electronic required vacuum tubes — an invention dating back to the beginning of the 20th century that had yet to be improved on.


Smith Chart Fundamentals

After reading this introduction to the Smith Chart, you will have a better understanding of impedance matching and VSWR — common parameters in a radio station.


Dealing With Diodes

in Just for Starters

The most common problem with power supplies is diode breakdown. Sometimes, they are killed by shorts elsewhere in the circuit. However, they will occasionally quit from old age.



Projects

Build A Data Logger - For Less

I often need some kind of data logging ability. Whether it’s measuring a battery voltage under load, temperature under the house, or light levels in the garden, it seems there’s always a need to sample sensor measurements over time for something. Happily, a data logger makes an excellent embedded control project; you end up with a useful gadget that is fun to build.


Digital R/C Airplane Camera

I’ve always been interested in photography and, when I first saw an advertisement for a “key chain digital camera,” I had to get one. In fact, I got two, sincethey were inexpensive and so small that I figured I would lose one.


Focus On The Shot, Not The Shutter

This project features a simple, small unit and full-use capabilities for arial, wildlife, and physically dangerous photography.


Garage Parking Assistant

Looking for an easier way to park your car or truck in the garage? Read on. Parking vehicles accurately in a standard-sized garage requires judgment, experience, and a little bit of guesswork. In my own case, there isn’t enough room to walk in front of my van if I pull it in too far. If I don’t pull in far enough, the rear bumper of the van will block the garage door’s closing path. This has been a challenge for several years...


The Ever Shrinking µC - PART 1

Six Pins and One MIP — If You Can See It!


The Telephone Rang Indicator

Build This Device That Informs You When Someone Has Called Your Telephone


Theory of Zeroing Circuitry

Cancel Out Your DVM Lead Resistance


AM Radio Tx

Use Your Boombox as a PA System


An Automatic Audio/Video Switch

I was pretty satisfied with my home entertainment setup. The TV was connected to a cable box, VCR, and a DVD player through a RadioShack ([url=http://www.radioshack.com]http://www.radioshack.com[/url]) four-way audio/video selector (model 15-1976). This particular unit is a push button model, which is both inexpensive and reliable. Having to manually switch inputs didn’t seem to be much of a hassle to me, since — for the most part — you had to get up to insert a tape or DVD, anyway.


Multi-Protocol USB

The vast majority of USB devices available on the market today have at least one thing in common: They all use microcontrollers to implement the task at hand. Whether it’s in the form of a USB serial engine sharing the same piece of silicon with a microcontroller or a simple connection between the two on a printed circuit board, the use of a microcontroller for just about any USB-based task is virtually inescapable ... that is, until now.


Remote Temp Logger

Recently, I needed to acquire some temperature data from multiple remote locations and decided to avail myself of the phone system. For the data acquisition unit, I decided to use an Atmel ATmega 8. This processor has plenty of horsepower for the task and a high performance A/D converter.


Web-Enabled X-10 Home Automation Controller

Glue Your X-10 Devices to a Webpage


Multiplexing To Get More Outputs

Assuming that your system has some digital outputs, but you need more outputs for the current project you’re working on, what do you do? This article will explain how to add as many digital outputs to your system as you desire.


Palm Programming: An Introduction

Developing applications for a Palm device can be costly. Not only that, but it can be confusing and difficult. However, it doesn’t have to be all that (well, not costly, anyway). Using free or very low-cost tools, you can get underway almost immediately and be developing programs that run on the Palm in no time.


The Digital Energy Saver

One of the most common problems I encounter is leaving my soldering iron on, only to discover days later that I have ruined a good tip and wasted energy. I have a mechanical timer in my machine shop for a small air compressor.


GPS 2SX: BUILD A STAND-ALONE GPS - PART 1

With an inexpensive surplus OEM GPS board, BS2 sx, and some other parts, you can build a GPS unit customized to your needs. This first part of two describes the hardware. The second part will describe the software.


JAVA POWER

Be the envy of your colleagues with this über-nerd coffee mug that generates power from heat using the same energy converters that are used on deep space probes! Equipping a mug with thermoelectric energy converters and heatsinks will allow you to drive a small motor or other electrical device. You can even claim to be environmentally responsible by extracting useful work out of heat that would otherwise just go to waste.


THE ELECTRONIC SNIFFER

My wife and I were taking our morning constitutional walk up the hill when I noticed the smell. The wind was from the south. “Do you smell that?” “What?” she said, “I don’t smell anything.” “Our neighbor must be gluing some PVC pipe or fiberglassing something.” I didn’t think much more about it, but the smell continued off and on for the next couple of weeks...


THE ENIGMA MACHINE - PART 4

This is the last part of the Enigma series. In some ways, it should really be the first because The Enigma Machine grew out of these high power observations. It was only after the electrical, physical, and chemical experiments were performed that enough information became available to design it.


COMPUTER AUDIO MULTIPLEXER

Sometimes, it would be convenient to connect a cell-phone style headset to a computer for telephony or video conferencing.


THE ENIGMA MACHINE - PART 3

The Enigma Machine generates high voltage pulses that are safe to play with. In the first two installments, we saw how to build it and witnessed some of the more obvious strange effects. The vibration effect (where a dry finger brushes an empty soda can on the machine causes a vibration, but a damp or stationary finger does little) is probably the most apparent. This month, we'll look at some of the less obvious — but still very strange — effects. We'll also show how you can transfer an electric


SELF POWERED DIGITAL METER

The simple circuit described in this article allows your digital meter to be self-powered from the same voltage it measures. This sounds simple and straightforward, right? Unfortunately, it is not.


THE ENIGMA MACHINE - PART 2

Last month, we examined two designs for building the Enigma Machine. We saw that it is a device that produces pulses of 1200 volts at a rate of a few Hertz to a couple of hundred Hertz. Because the high voltage is completely isolated from the outside, no significant current flows. Therefore, it’s safe to play with. This month, we’ll look closely at the vibration effect, as well as experiment with other properties of high voltage.


AN ANALOG SINE WAVE SIGNAL GENERATOR

A sine wave signal generator can be used to measure the frequency response of filters and amplifiers. Simply connect the signal generator to the input of the circuit under test and adjust the output of the generator to an appropriate amplitude. Next, measure the output voltage of the circuit at various frequencies with an oscilloscope. A frequency response graph can then be plotted with this data.


BUILD A SIMPLE SYNTHESIZER

The output frequencies from audio signal generators are not always either stable or accurately specified. An alternative is Direct Digital Synthesis (DDS). This process creates the desired output from numerical samples and generates any frequency you set with crystal accuracy.


THE ENIGMA MACHINE - PART 1

This is one of those things that seems just a little interesting at the start, but, as you look closer, it gets stranger and stranger. It’s a simple, plain, plastic box. It has a knob, LED, and power connector. When you turn it on, it doesn’t seem to do anything at all. It just sits there. However, put an empty soda can on the machine and lightly rub it with a dry finger. The can vibrates. Yet, this does not happen with a stationary finger or a damp finger.


BUILD AN ARCHOS REMOTE

This project provides a wired remote control for certain members of the Archos family of hard disk-based Jukebox MP3 players and recorders. Key features of the design are...


BUILD THE X-10 TRANSMOGRIFIER

When I was 13, my dad came to me with a challenge to build something my grandpa designed and called a BX24-AHT Transmogrifier. This was my first attempt at such a big project — much less a project that involved soldering. Like most 13-year-old boys, I wasn’t too interested because I thought the idea sounded boring, but, in the end, I agreed to take on the job. It started out slowly, mainly because my dad and grandpa were trying to teach me what each part did. Eventually, we got to the soldering


VIDEO SIGNAL GENERATOR

Have you ever wanted to add an inexpensive video text display to your project? Well, now you can!


A SIMPLE HDD EXERCISER

My son, Tim, asked me, “Hey, Dad, can you make something like I saw at Comdex?" He had just come home from a computer-oriented seminar and wanted to find out if we could make the heads on a defective hard drive rattle back and forth for Show and Tell — silly question. His older sister, Joy, had asked about a louder metronome. His younger sister, Robbi, had asked about a violin-tuner. Joy now has a loud metronome and Robbi has a tuner (Nuts & Volts, November 1999). ..


A SIMPLE ONE-MHz FRQUENCY COUNTER

If you work with digital or analog oscillators, at some point you will want to double-check their operating frequency. Analog oscilloscopes will only get you within a half-order of magnitude or so; a good frequency counter will take you the rest of the way.


HAND-HELD MESSENGER

I am sure that everyone has the experience of being surprised by an unexpected message on occasion. It could be a declaration of love on a giant stadium screen, a greeting left behind by a plane, or a commercial sign beside the highway. Wouldn't it be nice to be able to deliver a personal message to impress your friends when they least expect it? Here is a simple gadget that enables you to wave your personal messages in glow-in-the-dark words, pictures, or both.


Magnetic Saturation And The 100 Amp DC Current Transformer

An Alternative to Using a Series Shunt


Build The Muscle Whistler

There are 656 muscles in the human body and all of them generate a small voltage potential when they are activated. This voltage — which is called myoelectricity or EMG — is present on the surface of the skin surrounding the muscle. The detection of this signal is important in both clinical medicine and medical research.


Pocket Geiger Unit

Hunt for zoomies with this minimal G-M tube driver and detector.


The Stereo 6T9

Building a Vacuum Tube Amplifier


The Amazing Frisbee Black Box or BASIC Stamp Frisbee

Make an ultralight, easy-to-assemble, acceleration recorder that you can use to measure the dynamics of small vehicles.


Stand-Alone Watchdog Timers

Watchdog timers are an excellent way to insure that a microcontroller-based system continues to operate unattended if occasional failures occur.


The Capacitance Connection

After installing some low voltage yard lights, I applied power and one of the strings did not work. It became quite easy to tell that I had an open somewhere between the transformer and the first light in the string, but where?



Columns

Personal Robotics
by Mike Keesling
A Look at Robotic Behavior
At the rate I have been adding motors, drivers, and sensors to my projects, I will be in a lot of trouble in only a few years. I have done 12 motored centipedes, 18 jointed hexapods, and I am planning a robotic ecosystem with 30 robots with three motors each. Of course, at some point, this has to stop; I’ll need to scale back.

The Design Cycle
by Peter Best
A Specialized DSP-Equipped Microcontroller ...
To perform DSP (Digital Signal Processing) tasks, you’ll need a bit more than just math and some fancy programming. DSP hardware traditionally came (and still can come) as a dedicated DSP IC, which requires special compilers and debugging tools.

Just for Starters
by Mark Balch
Applying PWM — A Light Dimmer
Varying the power delivered to DC loads is a common problem in projects — such as robotics — where motors and lights require more control than simply on/off. Rapidly changing supply voltage to a DC motor or light is often impractical or disallowed by the electrical characteristics of the load.

Open Communication
by Louis E. Frenzel
Back to the Bands
A weekend project to return to amateur radio with kits — it doesn’t get any better than this.

Stamp Applications
by Jon Williams
BASIC Stamp Accessories Made Easier
Not long after the BASIC Stamp started a revolution in small microcontrollers, Scott Edwards started what turned into a cottage industry: serial accessories. Thanks to the new (and free!) SX/B compiler from Parallax, you, too, can join the serial accessory club ... and do so much more.

In The Trenches
by Gerard Fonte
How to Make Projects That Work
There is probably nothing more frustrating, annoying, and embarrassing than spending a week on a "simple" project that doesn't work, only to have someone else do it in an afternoon and with a handful of junk-box parts. What makes some people better at getting things to work properly? In this special all-projects issue, we'll look at ways to make you more successful in making projects that work.

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Micro Memories
by Edward B. Driscoll, Jr.
25 Years Into the Future — 1980s The Third Wave
Many science and science fiction writers have written books that predict the future. By the 1970s, a term was coined for these sorts of authors: futurists. Few books, however, got the future — the future that we’re living in right now — as right as Alvin Toffler’s The Third Wave, which celebrates its 25th anniversary in 2005.

Stamp Applications
by Jon Williams
I2C Again — and the Case for Continuous Improvement
I get the idea that a lot of BASIC Stamp users have discovered the fun and utility of the myriad (over 1,000) of I2C devices available today — even those users that don’t have the BS2p or BS2pe with the built-in I2COUT and I2CIN instructions.

In The Trenches
by Gerard Fonte
In The Trenches
At some time in an engineer's career or in a business' development, a decision about specialization or generalization will occur. This month, we'll discuss and examine various factors and implications of generalization and specialization. Clearly, it's useful to consider the good and bad points of each position well before you face the choice.

Near Space
by L. Paul Verhage
Modifying a PenCam for Use in Near Space Applications
I like to collect data. If I can send a near spacecraft (NS craft) to 100,000 feet and return data on cosmic rays, I’m in heaven (or maybe it’s near heaven).

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Let’s Get Technical
by James Antonakos
Shrinking Bits — A Second Look at Digital Data Compression
Last time, we examined the applications for lossless and lossy data compression methods. In this second look at digital data compression, we will take a look inside these different compression techniques:

TechKnowledgey
Techknowledgey 2004
Events, Advances, and News

In The Trenches
by Gerard Fonte
IN THE TRENCHES
The characteristics that are associated with engineers are both stereotypical and somewhat accurate. This month, we’ll take a not-too-serious look at some of these traits to see what they are. After all, it’s important to understand how others see the profession, as well as what features make someone a good engineer. (Note that the pronoun “he” is used for simplicity and brevity. Most hardware engineers are male; however, more women are entering the field every day.)

Just for Starters
by Mark Balch
JUST FOR STARTERS
A reader recently asked me how to design a counter. Counters are a basic digital logic building block and have a multitude of uses. Counters advance through a consecutive numerical sequence — either up or down — each time a clock pulse is driven. They are used to divide high frequency clocks to yield lower frequency clocks, for state machines and basic event counting. You can design a counter from scratch with truth tables by applying Boolean logic. In this article, we will discuss using off-the

Near Space
by L. Paul Verhage
NEAR SPACE
I like to collect data. If I can send a near spacecraft (NS craft) to 100,000 feet and return data on cosmic rays, I’m in heaven (or maybe it’s near heaven). For most people, though, they want to see photographs. To them, your backpacking trip to the bottom of the Grand Canyon isn’t interesting unless you can share photographs.

Open Communication
by Louis E. Frenzel
OPEN COMMUNICATION
In my August column, I wrote about the new ZigBee wireless system. In this issue, I want to complete the coverage of the various short range wireless options available today.

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Stamp Applications
by Jon Williams
STAMP APPLICATIONS
The night is drawing closer ... my favorite night of the whole year: Halloween. I love Halloween — the costumes, haunted houses, parties, and friendly exchanges with trick-or-treaters; Halloween is the best. When I have the chance, something I like to do is build Halloween-oriented props and decorations and you can bet that many of those props get some sort of automation via the BASIC Stamp microcontroller.

TechKnowledgey
by Jeff Eckert
Techknowledgey 2004
Events, Advances, and News

The Design Cycle
by Peter Best
The Design Cycle
For some, debugging is the not-so-fun part of developing hardware and software applications. Whether you’re designing complex subsystems for fighter jets or putting the finishing touches on that pet microcontroller project in your workshop, be certain that debugging will be part of your design cycle.

In The Trenches
by Gerard Fonte
IN THE TRENCHES
There is probably no other profession that depends upon specifications as much as engineering does. You create something to meet some set of requirements or you rely on the performance data of various components. Very often, both aspects are employed at the same time. Knowing how to make, read, and understand specifications is an important part of engineering.

Just for Starters
by Terence Thomas
JUST FOR STARTERS
Materials that can conduct current (silver, gold, aluminum, copper, etc.) contain large numbers of loosely held electrons. Their resistance to the flow of current is measured in just a few millionths of an ohm per centimeter. Insulators — such as glass, rubber, and plastic — have very few loosely held electrons and their resistance to the flow of current is measured in a few million ohms per centimeter.

Let’s Get Technical
by James Antonakos
LET’S GET TECHNICAL
Data compression has been around for a long time. If you’ve heard the expression, “A picture is worth a thousand words,” then you are familiar with the basic principle of data compression: replacing one set of symbols with another, smaller set. A high resolution photograph of an object is a better description than a mere thousand words can evoke.

Near Space
by L. Paul Verhage
NEAR SPACE
The study of electrostatics was our first step in the field of electronics. In electrostatics, electric charges are relatively stationary. So, the natural philosophers (early scientists) who studied the phenomenon of electrostatics concentrated primarily on the creation, storage, and interaction between the two types of electric charges. One of their tools was the electroscope, a device consisting of two metal foil leaves draped over a metal rod and protected within a glass jar.

Personal Robotics
by Mike Keesling
PERSONAL ROBOTICS
Some of us build robots for the educational aspects, others for a creative outlet. Some of us undoubtedly have a god complex or parenthood issues, but there is one thing that you can’t deny and that is that robots are great for impressing your friends.

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Stamp Applications
by Jon Williams
STAMP APPLICATIONS
On a recent return trip from Starbucks, I noticed myself doing something that actually made me laugh. While steering with my left had, I would reach down with my right hand to adjust the coffee spout such that coffee would not slosh out while I was cornering. Honestly, I laughed out loud, then immediately thought that, if I had an accelerometer, a stepper motor, and a BASIC Stamp, I could keep both hands on the wheel. An idea was born ...

TechKnowledgey
by Jeff Eckert
TECHKNOWLEDGEY 2004
Events, Advances, and News

In The Trenches
by Gerard Fonte
IN THE TRENCHES
New ideas abound, but it's important to be able to recognize bad ideas, as well as good ones. Good ideas can make lots of money. However, it's probably more important to be able to see bad ideas from the start. These bad ideas may very well cause problems in the future from lost sales, lawsuits, and wasted time and money.

Just for Starters
by Mark Balch
JUST FOR STARTERS
A reader’s letter suggested that I explain the basic electrical units used to describe DC circuits. These units are electric potential (expressed in volts, V), current (expressed in amperes, A), resistance (expressed in ohms, W), and power (expressed in watts, W). Understanding how these quantities relate to each other allows you to perform basic circuit analysis...

Near Space
by L. Paul Verhage
NEAR SPACE
This month, we are going to make one (or more) temperature sensors for a HOBO data logger with external channels. The work doesn’t end there, however. To turn the data our sensor records into the readings we require, we’ll need to determine the equation that calculates the temperature from recorded voltage readings. From there, we will produce a chart of temperatures versus elapsed time.

Open Communication
by Louis E. Frenzel
Open Communication
We seem to be on a path leading to a totally wireless electronic lifestyle. The progress has been continual over the years, thanks to semiconductor technology and other advancements. More recently, there has been a flurry of announcements that make wireless everything possible. ZigBee is an important aspect of this.

Personal Robotics
by Mike Keesling
PERSONAL ROBOTICS
This month, I would like to take a few words to update everyone on the progress of some of my other projects, tease you with some new ones, talk about some things that don’t warrant a whole article, and talk a little philosophically.

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Stamp Applications
by Jon Williams
STAMP APPLICATIONS
Yep, I’m still a real man, alright. I still live in the great state of Texas, drink milk right out of the carton, leave the toilet seat up, and — in addition to the five remotes I have to run the electronics in my entertainment center — I can now control anything else in my home from my Pocket PC. Yeah, buddy, I have enough control to make Tim Allen grunt with manly-man joy.

TechKnowledgey
by Jeff Eckert
TECHKNOWLEDGEY 2004
Events, Advances, and News

The Design Cycle
by Peter Best
THE DESIGN CYCLE
Think of a number between 0 and 10. Is your number 3? Did I guess right? If I guessed right, would you say that your mind generated a random number and I just happened to be lucky enough to guess what it was? Or, do you have an affinity to the number 3? Do you have three kids? How about three cars? Why did you come up with the number 3? If I missed the guess and your number was something other than 3, how did you come up with that particular number? Was your choice of numbers really random?

In The Trenches
by Gerard Fonte
IN THE TRENCHES
A Printed Circuit Board (PCB) is more than just traces that connect components together. It is an integral part of any design. A good PCB design is one that you never notice. A bad design can cause headaches for years.

Just for Starters
by Mark Balch
JUST FOR STARTERS
Getting started on a new design isn’t easy when you have trouble figuring out what types of circuits are necessary to implement the project’s requirements. Last month’s article discussed how to decompose high level requirements into a set of architectural building blocks and then presented analog and digital implementations of a basic LED blinking circuit.

Let’s Get Technical
by James Antonakos
Let’s Get Technical
In the case of a communication system, errors happen while information is being transmitted, while it is being delivered to its destination, or while it is being received. Perhaps a stray magnetic field sliced through a floppy disk and altered a few 0s and 1s. Maybe a lightning strike produced a spike in the power lines, which, in turn, caused a few cells in a RAM on a computer’s motherboard to change.

Micro Memories
by Edward B. Driscoll, Jr.
MICRO MEMORIES
Every industry has its own trade show. For consumer electronics, it’s CES in Las Vegas, NV, for computers, it’s Comdex, and for the music instrument industry, it’s NAMM — short for North American Music Merchants.

Near Space
by L. Paul Verhage
NEAR SPACE
By using a photocell (CdS) as one element in a voltage divider, you can construct a simple light sensor. Because it uses a photocell, the light sensor’s spectral sensitivity is very similar to that of the human eye. After you finish reading about how to build this light sensor for your HOBO data logger, I’ll explain a very interesting finding about designing voltage divider-based sensors.

Personal Robotics
by Mike Keesling
PERSONAL ROBOTICS
It sounds easy, but — for many of us — it is a major mental block. We dream and hope, yet cannot achieve. I go through the same thing when it comes to programming or writing, but the difference is, you can easily destroy something if you build it improperly, but playing with words and code is like playing with vapor. Like the old saying, “but words will never hurt me,” code doesn’t break like physical things do.

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Stamp Applications
by Jon Williams
STAMP APPLICATIONS
If you ask my close friends, they’ll tell you that I’m as stubborn as a mule, yet I maintain the right to be human; therefore, the right to be wrong. I’d like to think that, when I am wrong, I admit it — I try, anyway.

TechKnowledgey
by Jeff Eckert
TECHKNOWLEDGEY 2004
Events, Advances, and News

In The Trenches
by Gerard Fonte
IN THE TRENCHES
This month, we'll apply basic probabilities. We'll start by looking at some fundamental concepts and the mechanics of probabilities.

Near Space
by L. Paul Verhage
NEAR SPACE
There are several data loggers that are capable of fitting inside a lunch bag. By carrying one of these on the mission, you can collect additional science and engineering data. Since the data loggers collect data at a fixed rate (you program this rate into the data logger), you can relate the recorded data to the altitude of the near spacecraft.

Open Communication
by Louis E. Frenzel
OPEN COMMUNICATION
Despite the fact that spread spectrum (SS) technology is very widely used in every day wireless applications, few people — including technical types — actually know how it or its CDMA derivative works. It is one of the more complex wireless methods, but it has some really great benefits. With over 70% of US cell phones using this method, chances are you use a CDMA cell phone. Here is an introduction to this killer wireless technology.

Personal Robotics
by L. Paul Verhage
PERSONAL ROBOTICS
Often, we need our robot to make or break a circuit. This lets our robot operate a sensor, emit a warning tone, or even fire photon torpedoes. While we humans are really great at pushing buttons, robots have a problem because they tend to lack fingers and opposable thumbs. So just how do robots turn on and off circuits?

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Stamp Applications
by Jon Williams
STAMP APPLICATIONS
Like most men, I’m not real big on the idea of shopping. I know what I want. I want what I want. I know where to go get it — and that’s precisely what I do: I go get it. Of course, for every rule there is an exception and, for my shopping rule, there are two: book stores and Tanner Electronics in Dallas, TX. I love going to Tanner — even when I don’t need anything specific...

TechKnowledgey
by Jeff Eckert
TECHKNOWLEDGEY 2004
Events, Advances, and News

In The Trenches
by Gerard Fonte
IN THE TRENCHES
Statistical analysis is an extremely powerful tool. It is important for an engineer to be familiar with techniques and methods of statistical analysis. Statistical procedures are often used to define reliability, but they are also very useful in signalprocessing.

Let’s Get Technical
by James Antonakos
LET’S GET TECHNICAL
I have chosen to finish my three-part fiber series with an application that uses a fiber optic cable as part of a high-frequency oscillator. Called a Fiber Optic Ring Oscillator, it makes use of a length of fiber to generate a square-wave signal; the frequency of its oscillation depends on the length of the fiber and the speed of light inside the fiber.

Micro Memories
by Edward B. Driscoll, Jr.
MICRO MEMORIES
Using the telephone is such a hassle these days; women have to make sure their makeup and hair is just so and all but the most Cro-Magnon of men want to appear clean-shaven and well-groomed when calling their wives or parents.

Near Space
by L. Paul Verhage
NEAR SPACE
Now that you have a near space (NS) craft, what experiments can you perform with it? Since it has a simple tracker — not a flight computer — there are some limitations. There are many experiments that function on their own; however, before you can process your science results, you need to understand the format of the data transmitted by the Tiny Trak 3 in your NS craft.

Personal Robotics
by Mike Keesling
PERSONAL ROBOTICS
Let’s face it, the real core of robotics is information processing. What is done with the information a robot gathers truly determines its behavior. At the simplest level, that information could be a series of commands and times to perform them. Even at that level, there is still sensing going on; in this case, we are sensing the ticks of a clock. While this is a great start, watching your robot roll off your desk or ram into a wall because it had no sense of its surroundings gets old really fas

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

Stamp Applications
by Jon Williams
STAMP APPLICATIONS
One of the great things about my job — aside from the fact that I get to work with BASIC Stamps all day long (and get paid for it!) — is the customer contact I am able to have. Almost all of my contacts are very friendly and find what I get to do here with Nuts & Volts useful — sometimes even a bit entertaining. Often, I get messages that are cries for help and I always enjoy helping, when I can. From time to time, a customer will alert me to a part that I hadn’t previously worked with...

In The Trenches
by Gerard Fonte
IN THE TRENCHES
Much of a design engineer's time is spent making things that aren't working work. Often times, this can be a real challenge, especially if the design steps (circuit design, board layout, assembly, etc.) are performed by different people. The engineer must determine not only the problem with the product, but also which design step is faulty and how to correct it. This month, we'll look at some approaches that can help in such situations.

Let’s Get Technical
by James Antonakos
LET’S GET TECHNICAL
This month, I will show the details behind the transmitter and receiver circuits and explain how a software protocol is used to transmit eight bits of data.

Micro Memories
by Edward B. Driscoll, Jr.
MICRO MEMORIES
In 1978, the Internet existed, but it was still largely restricted to universities and the military (and still called Arpanet.) It was only a year before that Hayes had released the first modem for PCs. While CompuServe (see the October 2003 “Micro Memories”) and the Source were positioning themselves as national online services, Ward Christianson and Randy Suess of Chicago had another idea for connecting groups of users to computers: the bulletin board systems or BBS.

Near Space
by L. Paul Verhage
NEAR SPACE
This month's article discusses some of the benefits gained through beginning your own program and explains how you can build an inexpensive near spacecraft and use it in an amateur science project. Talk about an awesome science fair project!

Q&A
by TJ Byers
Q&A
In this column, I answer questions about all aspects of electronics, including computer hardware, software, circuits, electronic theory, troubleshooting, and anything else of interest to the hobbyist.

TechKnowledgey
by Jeff Eckert
TECHKNOWLEDGEY 2004
Events, Advances, and News

Just for Starters
by Mark Balch
Starting A New Design — Part 1:  Architecture And Implementation
In this first installment of a two part series, we’ll walk through a small project scenario to see how to go from concept through design.

Just for Starters
by Mark Balch
Interface Choices — Part 1: Transistors
This month's column discusses transistor-based isolation techniques for DC control signals, as compared to analog signals such as audio or video.

Just for Starters
by Mark Balch
Reading Schematic Diagrams
Reading and interpreting schematic diagrams is an important skill for anyone who wants to work with electronic circuits.

Personal Robotics
by Mike Keesling
Universal Robotics Controller
Very often, in our quest for functionality, we stray away from our processor of choice when we need a feature that just isn't found in our magic bag of tricks. Often times, we are forced to look in directions we wouldn't normally consider.