BUILD A MUSICAL LASER RAINBOW MACHINE
Make liquid light with lasers and music.

I’ve been searching for a way to give our band’s performances the kind of visual elements that can only otherwise be achieved by true lighting artists. As a musician, inventor, and laser enthusiast, I decided to draw on all my hobbies and have created a light machine that has unique responses to each tone, frequency, and beat.

LATTICE WAVE DIGITAL FILTERS

This article is a result of my investigation into LWDFs which were just too cool to pass up.

Typically, when I find a technology that interests me, I go overboard in my research and spend lots of hours playing with it in order to understand it. LWDFs were no exception. This article and the accompanying design tool were a result of my investigation into LWDFs which were just too cool to pass up.

BUILD AN ANALOG-STYLE LED CLOCK

Part 2 – Finishing the circuit, making the printed circuit board, building the clock, and how the software works.

Last time, we looked at a test circuit that had 12 LEDs. Using Charlieplexing, we ran those LEDs with only four I/O lines and determined that expanding the LED matrix to 14 I/O lines would enable us to individually control 182 LEDs. We also looked at how to incorporate the reading of four pushbuttons by connecting them to the LED matrix with a handful of other discrete components. This time, we’ll expand the LED matrix to run the 182 LEDs that the clock uses and make a printed circuit board (PCB) for the clock. Then, we’ll wrap it up with a discussion of how the software works and put the finishing touches on our unique timepiece.

RESTORATION OF AN ABUSED 1965 MCINTOSH C22 ALL-TUBE PREAMP
We’ll help out an abused 1965 McIntosh C22 all-tube preamp.

The C22 — one of my holy grail audio electronics acquisitions — is known for quality in engineering and construction and audiophile performance. The C22, which originally sold for $330 in 1965, now sells for between $3,000 and $6,000, depending on condition. Even if you don’t own a C22, by following along, you can pick up pointers for your own vintage restoration project — especially when it comes to restoring improperly serviced gear.

Super Awesome Cube Kit

Need soldering experience? This is the kit for you!

Soldering skills are required by industry manufacturing electronic products as well as electronics enthusiasts developing new prototypes. What distinguishes the skilled solderer is the ability to perform work at a level that insures reliability. Here’s a kit that even though it’s electronically simple, it provides the builder with an array of soldering challenges and hours of soldering experience.

Find It in the NV Webstore

FLOATING POINT MULTIPLICATION AND DIVISION WITHOUT HARDWARE SUPPORT
Using Horner’s method to provide floating point support on microprocessors or microcontrollers that don’t have support built in.

To use the digital filters necessary for a color organ project, I needed to be able to multiply floating point numbers on a microcontroller that doesn’t even know how to multiply integers. Horner’s Method to the rescue!

Get More Details Here!

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THE ARDUINO GRAPHICS INTERFACE

Part 2 — Software Concepts and Support Library.

In Part 1, we described the background and hardware build of the Arduino Graphics Interface (AGI). With this platform, you can turn an analog oscilloscope into a very high resolution graphics display device. This time, we’ll complete the project by describing the details of the XYscope: the software libraries and sample code that make the AGI hardware easy to use and integrate into any graphics display application.

SCREEN PRINT AND REFLOW SMT BOARDS AT HOME
Enjoy SMD capabilities using the at-home procedure outlined here.

Soldering the tighter pitch on surface-mount devices can be a problem for a home workshop. Would you like to take advantage of SMD capabilities? The following method I’m going to take you through is far from the sophistication of major screen printing and reflow equipment, but it gets the job done — even double-sided SMT boards. Plus, You can do it right in your garage or workshop.

BUILD AN ANALOG-STYLE LED CLOCK — PART 1
This circuit uses Charlieplexing to individually control 182 LEDs with only 14 I/O lines and to read four pushbuttons by connecting them to the LED matrix with a handful of other discrete components.

Driving LEDs using the lowest possible pin-count is a common challenge for folks creating projects with microcontrollers. Complementary LED drive, also known as “Charlieplexing,” allows a large number of LEDs to be controlled with a relatively small number of I/O pins. This fun digital LED clock project is a hands-on example of how Charlieplexing can be used to stretch your “pin budget!”

HOW YOU CAN INTERCEPT SECRET MESSAGES BEING SENT TO SPIES
Unidentified radio broadcasts have been transmitting coded messages using numbers for years.

Believe it or not, there are powerful radio stations all over the world sending out messages to spies every day, and you can hear them with an inexpensive shortwave radio and a simple antenna. You probably won’t be able to decode them, but it’s a real kick to tune in these clandestine signals.

HIGH VOLTAGE OP-AMPS, A CURRENT SENSOR, AND A 32-BIT MICROCONTROLLER: HOW ABOUT A LAB POWER SUPPLY?

This article will show you all the steps needed to design a programmable supply.

In most linear power supplies, voltage and current limits are entered with rotating knobs. For faster and higher precision, I wanted to design a lab power supply for my bench with voltage and current limits entered via a keypad. I included a microcontroller to take care of the keypad input functions but wanted the basic supply to be linear — no switching and less noise! Here’s how I did it.

THE ARDUINO GRAPHICS INTERFACE
Part 1 — Design Concepts and Hardware Fabrication.

Turn an Arduino Due and a leftover analog oscilloscope into a high resolution computer graphics display and gain valuable insights into computer graphics, digital-to-analog conversion (ADC), and advanced Direct Memory Access (DMA) hardware and software techniques.

THE CHALLENGING LIFE OF URBAN HAMS
Being an amateur radio operator within city limits can be a hassle.

It isn’t easy being a ham operator inside city limits. Restrictions in where you can place antennas, power requirements which can disrupt communications and entertainment systems, and just the sheer amount of electrical noise to contend with can take the fun out of the hobby.

TESLA INVENTED RADIO, NOT MARCONI!
Make sure your history is correct and give proper credit where credit is due.

Okay, I’m probably as guilty as a lot of you in believing that Marconi actually invented radio. However, he did not and it has taken decades — actually, well over a century — for the truth to come out. In fact, I’m convinced that the truth is still not well known. Not to burst your bubble or anything, but here’s the real story.

LED ‘GRAPH’ CIRCUITS

Here’s a variety of practical LED dot-graph and bar-graph analog-value display circuits.

One of the most popular types of multi-LED indicator circuits is the so-called analog-value indicator or ‘graph’ display, which is designed to drive a chain of linearly-spaced LEDs in such a way that the length of chain that’s illuminated is proportional to the analog value of a voltage applied to the input of the LED-driver circuit. This way, the circuit acts like an analog voltmeter.

THE RETRO-SHIELD: WHERE THE PAST MEETS THE PRESENT
Combine a vintage vacuum tube with an Arduino for an updated version of an AM broadcaster.

Several months ago, I bought a vintage Allied Radio Knight-Kit 12-in-1 Electronic Lab on eBay. It used a 12K5 low voltage vacuum tube instead of transistors. As I was wiring up my "wireless AM broadcaster" project, it hit me. Why not combine the past with the present? Put an Arduino with a vacuum tube shield — a Retro-Shield!

ELECTRONICS: WHAT’S IMPORTANT FROM THE OUTSIDE LOOKING IN?
Here’s how to do good by your favorite electronics hobby.

Keep studying, keep extending your practical electronics experience, and, above all, have some fun along the way.

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GOOD PCB DESIGN
Keep your project on schedule with good circuit board design.

Designing a circuit board for ease of manufacturing can not only help insure your project stays on schedule, it makes sure the redo’s aren’t left for someone else. You have control over at least some parts of the making process.

Get More Details Here!

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READY PLAYER 2: CC3200 WI-FI & IoT MCU — PART 2

Working with CC3200 Launchpad and Code Composer Studio (CCS).

My article, “Build the IoT Sump Pump (or Pretty Much Anything IoT)” generated curiosity about some of the tools utilized to create the device. With the capabilities of CC3200 Launchpad and Code Composer Studio (CCS), we can further explore two more items of our device design: How to adopt a third-party project to work with your environment; and how to upload your code to the external Flash memory.

BUILD A DOTSTAR LIGHT PAINTER
Use microcontrollers and a DotStar LED strip to develop custom photography from images you upload yourself.

Long exposure photography captures the path of light over time, smearing moving elements to produce a single photo which creates a new realm of artistic photography. However, popular subjects of light exposure photographs are uncontrollable (stars, car headlights, etc.), so we made a light painter using microcontrollers and a DotStar LED strip to develop custom photography from images uploaded by a user.

RESPIRATORY MASKS
Respiratory masks should always be part of your safety tool arsenal.

The current virus epidemic aside, respiratory masks should be part of your permanent tool arsenal when working with chemical vapors or fine dust, along with goggles to protect your eyes.

THE MAGIC OF ANTENNAS
If you really want to know what makes any wireless application work, it’s the antenna.

Here, we’ll summarize some of the most common types and make you aware of what an antenna really is and how it works.

TRANSFORMER BASED POWER FOR NIXIES

Discover a new way to power your Nixies.

Nixies were introduced when vacuum tube hardware automatically provided the high voltage they require. These days, circuitry typically runs on five volts or less, so finding the +170V or so for Nixie anodes can be a bit of a challenge. Here are three transformer based ways to obtain that high voltage in line-powered semiconductor-based devices.

READY PLAYER 2: CC3200 WI-FI & IoT MCU — PART 1
Working with CC3200 Launchpad and Code Composer Studio (CCS).

My previous article “Build the IoT Sump Pump (or Pretty Much Anything IoT)” generated curiosity about some of the tools utilized to create the device. It’s time to “ready Player 2” and penetrate deeper into the utilization of some of the software and hardware features that come with CC3200 Launchpad and Code Composer Studio (CCS).

HOW OLD IS OLD ENOUGH?
One of the most often asked questions in my inbox is ‘how old is old enough to begin working with electronics?

The answer, of course, is that it depends on the individual, what you mean by ‘working with,’ and the amount of supervision provided by an experienced or at least alert adult.

REPAIRING CIRCUIT BOARDS
Repairing any kind of PCB can seem intimidating, but a methodical approach helps in finding and fixing problems quickly.

Anyone interested in electronics is bound to encounter a dead board or two, whether it’s their own or someone needing help. What’s the best approach when confronted with a PCB that doesn’t do what it’s supposed to do? Here are several methodical steps to take, that range from simplistic to advanced.

THE SIRIUS METRONOME FOR THE SERIOUS MUSICIAN

One of the most important tools any musician needs is a metronome.

The circuit described here sports a number of impressive features that even more expensive commercial units can’t provide.

ADDING FM CAPABILITY TO AN ALL AMERICAN FIVE AM RADIO
Get FM capability without destroying the AM portion of your AA5 tube-type radio.

After retirement a few years back, I started collecting AA5 radios, restoring and selling them. People would ask whether they picked up FM and, of course, they did not. I started thinking about how to add FM capability without destroying the AA5’s AM operation. Here is my solution.

KNOW YOUR BASICS
To master the art of electronics, it’s important to learn the basics.

I’m talking Ohms Law, serial and parallel discrete components, and simple signal sources. This might seem self-evident, but since the introduction of the increasingly popular microcontrollers and standard sensors and effectors, it’s possible to create electronic devices without ever touching a capacitor or resistor.

OSCILLATORS, STATISTICS, Q, AND MUONS
Learn how to determine how well your oscillator is behaving.

In this article, you’ll learn about "Q" as it applies to assessing an oscillator. We’ll show a technique for measuring Q for a variety of oscillators, and see how it can be used to compare their performance.

AN EASY CATV COAX ANTENNA

Make antennas from unexpected materials.

A few years ago, we brought you a story about a guy building ham radio antennas from aluminum crutches. Now, he’s using cable TV coax for his dipoles.

HOW TO: BREADBOARDING
Develop breadboarding methods and habits that work well for you.

The goal of breadboarding is to mount electronic components on a supporting substrate and make all of the necessary electrical connections that result in a functional electronic device.

A MAKER’S DOZEN: DESIGNING AROUND FAILURE
When it comes to DIY, it’s not really a "failure rate" but a learning opportunity.

I just finished a major production run of simulators for training physicians on how to examine the eye. Based on my failure rate, I’d say that a proper maker’s dozen is 13.5 units. That is, if you need to make a dozen relatively complex devices, order enough spare parts for 1.5 additional units.