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Using Seven-Segment Displays — Part 1

Using Seven-Segment Displays — Part 1

A very common requirement in modern electronics is that of displaying alphanumeric characters. The best known type of alphanumeric indicator is the seven-segment display, which comprises seven independently-accessible photoelectric segments.


Light-Sensitive Circuits
Theory

Light-Sensitive Circuits

Electronic optosensors are devices that alter their electrical characteristics in the presence of visible or invisible light. The best known devices of these types are the LDR (light dependent resistor), the photodiode, the phototransistor, and the PIR (passive infrared) detector.


ISaAC — A New Add-on Adapter for the Raspberry Pi
Control

ISaAC — A New Add-on Adapter for the Raspberry Pi

For quite a while now, we have sought the ultimate add-on interface board to enhance some Raspberry Pi (RasPi for short) projects we want to pursue, including a mobile webcam and a wireless sensor network. For such projects to work, it's essential that our RasPi add-on meet several particular criteria.


Build Your Own Induction Charger
Wireless

Build Your Own Induction Charger

As an avid hobbyist, I wanted a convenient way to recharge my battery powered projects without having to tie up the USB ports on my computer. Borrowing from the concept of the wireless chargers on the market, I decided to build my own. So if you like the idea of having a wireless replacement for your USB port, open up your surplus parts drawer and let's start the induction process.


A Recording Radiation Counter
Data Acquisition

A Recording Radiation Counter

Are you exposed? Build this unit to detect and display levels of radiation, plus you can record months of data to keep track of just how toxic areas may be or become.


Build a Bat Detector
Science

Build a Bat Detector

Bats emit high frequency, short duration energetic pulses of sound and interpret the echoes that return to their ears. It is perfectly possible to identify bat species by careful observation using this detector as their call patterns are species-specific and can be quite distinctive.


How I Scratch-Built a Five Foot Long Radio-Controlled Submarine — Part 1
Editorial

How I Scratch-Built a Five Foot Long Radio-Controlled Submarine — Part 1

If building a submarine interests you, I have here a great project that will give you some good ideas and many techniques to learn. If you have a robotics project or an all-terrain vehicle or boat, follow along as I have some great building secrets to share with you, too.


Build a Wall Wart Power Monitor
Workbench

Build a Wall Wart Power Monitor

As an experimenter, I use wall warts all the time to power circuit boards, microcontroller boards, and even finished projects. However, during the checkout phase of a new circuit, wall warts present a problem. How do you measure their output when they’re plugged into a board or project box?


Wirespondence!
Editorial

Wirespondence!

Recording a message on a wire spool and mailing it off to family and friends became a growing fad called “wirespondence.” The magnetic wire recorder, ancestor to the tape recorder, had undergone great development during World War II. By the late 1940s, wire recorders were available in consumer equipment.




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The TAB Book of Arduino Projects

36 Things to Make with Shields and Proto Shields - Create fun and functional gadgets with the Arduino Uno and Leonardo boards with step-by-step instructions and detailed illustrations,

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Practical Electronics for Inventors, 4th Edition

Set up your own home electronics workshop and invent, design, build, test, and repair electronic circuits and gadgets.

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Solar Charge Controller Kit 2.0

Automatically charge your 12V lead-acid batteries up to 12 amps using solar cells.

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