Nuts and Volts - April 2014

Nuts & Volts (ISSN 1528-9885/CDN Pub Agree #40702530) is published monthly for $26.95 per year by T & L Publications, Inc., 430 Princeland Court, Corona, CA 92879. PERIODICALS POSTAGE PAID AT CORONA, CA AND AT ADDITIONAL MAILING OFFICES. POS TMAS TER: Send address changes to Nuts & Volts, P. O. Box 15277, North Hollywood, CA 91615 or Station A, P. O. Box 54, Windsor ON N9A 6J5; cpcreturns@nutsvolts.com.

4 April 2014

Cover photo provided by Matthew Roddy;

model is Shauna Toerner.

08 PICAXE Primer

Sharpening Your Tools of Creativity

PICAXE-Pi Communications — Part 2.

We’ll continue with our PICAXE-Pi communications experiments, and cover the basic techniques that can be used to send a PICAXE ADC reading to the Pi from any analog sensor we choose.

52 Open Communication

The Latest in Networking and Wireless Technologies

Software-Defined Radios Everywhere.

Virtually all radios today — cell phones and Wi-Fi WLAN, for example — are software-defined radios.

Find out exactly what SDRs are and how they work.

56 Smiley’s Workshop

Programming • Hardware • Projects

The Arduino Classroom.

Arduino 101/Chapter 4: Digital Input ...

Pushbuttons.

Learn how to design circuits with pushbuttons and how to utilize them to get your system to take action when they are pressed (or not).

68 The Design Cycle

Advanced Techniques for Design Engineers

Total Eclipse of the Cross Compiler.

The BeagleBone Black and Raspberry Pi are different in many ways. They are also alike in many ways. However, when it comes to programming them, the equalizer appears in the form of a Linux-based GNU cross compiler toolchain running under the umbrella of an Eclipse IDE.

20 Build the Ba TESLA Coil

How would of Nikola Tesla designed his famous coil if he had been able to access modern day electronic parts? Here’s one idea.

■ By Matt Bates

28 The Dryer Minder

While originally created for a specific purpose, this basic “notification” circuit can be implemented in many different applications.

■ By Jim Lacenski

34 The Decade Box Revisited

Decade boxes allow users to dial in precise amounts of electrical resistance to be inserted into a circuit they’re designing. Original boxes had faceplates with the values printed on them, but extra math was always involved. Here’s a handy update to that reliable piece of equipment.