The Arduino Inventor's Guide (53 page)

FIGURE A-10:
A water-soluble flux pen

Flux does wonders for soldering, but it is somewhat corrosive, so make sure you minimize contact with your skin and wash your hands immediately after use.

You’ll sometimes find when soldering that you’ve added too much solder or gotten solder in places that you didn’t intend. There are two tools to keep around on your bench that help remove unwanted solder. The first is
solder wick
, a finely braided copper mesh that resembles a ribbon, as shown in
Figure A-11
.

To use solder wick, place the wick over the solder joint you wish to remove, apply the heated soldering iron to the top of the wick to heat the wick and the solder joint below, and as the solder melts, it will wick away from your components into the copper mesh. Voilà!

FIGURE A-11:
A close-up view of solder wick

Be sure to hold the iron on the wick as you remove both the wick and the iron from your board. If you pull the iron away too soon, the wick will be soldered onto your board. If this happens, simply reheat the joint to remove the wick.

The second tool that can remove unwanted solder is called a
solder vacuum
or
solder sucker
. This nifty tool creates a vacuum using a plunger (similar to a syringe) and releases with the press of a button.

To use a solder sucker, first push down on the plunger to preload the tool. Next, heat up the solder joint you wish to remove until it is completely melted and liquid. Place the tip of the solder vacuum against the solder (while still holding the iron to keep it melted), and finally push the release button to suck away the unwanted solder.

If it doesn’t work, try again. It sometimes helps to add a bit more solder to the area you wish to remove solder from.

Resistors come in a wide range of values, but how can you tell what the value is by looking at the tiny component? There are no numbers or text!

Resistors use a color band system to show their values.
Figure A-12
shows how the banding system works.

Most resistors have four or five colored bands. The last band on the resistor specifies the
tolerance
, or the degree of variance, allowed by the manufacturer. Most of the time, your resistors will have a gold tolerance band, for 5 percent. This means the manufacturer allows 5 percent error on the value of that resistor. For example, the resistance of a 10 kΩ resistor with a 5 percent tolerance can fluctuate up to 500 Ω and still be considered a 10 kΩ resistor.

When you’re reading from left to right with the tolerance band (usually gold or silver) toward the right, the remaining bands specify
the resistance value. On a four-band resistor, the first two bands specify the base number, and the third band is the multiplier. On a five-band resistor, the first three bands specify the base number, and the fourth band is the multiplier.

For example, the first three bands on a 10 kΩ resistor are brown, black, and orange. Following the chart in
Figure A-12
, brown equals 1, and black equals 0, so brown-black means the base number is 10. The third band is orange, which specifies a multiplier of 10
³
, for a total of 10,000. Finally, the fourth band specifies the tolerance, which in this example is 5 percent (gold).

FIGURE A-12:
Resistor color cheat sheet

In case you need to look up resistor color bands later, you may want to dog-ear this page for reference. It’s okay—we won’t tell the librarian.

We hope you’ve enjoyed building the projects in this book. It was a lot of fun for us to come up with different project ideas that incorporated cardboard, paper, ping-pong balls, and other common materials, as well as the basic electronics. But the projects in this book are just a start. We hope they inspire you and help unleash your inner inventor! We encourage you to combine and mash up components and concepts from each of these chapters to create your own
Franken-duino
project! If you have comments or ideas that you’d like to share with us, please send us a note at
[email protected]
.

Best of luck, and happy building!

The community behind Arduino is vast. The Arduino IDE is downloaded nearly 600,000 times per month. While Google can find just about anything on the internet, here are a few other resources that we use regularly and recommend.

Arduino Learning Community
https://www.arduino.cc/en/Guide/HomePage

Arduino Language Reference
https://www.arduino.cc/en/Reference/HomePage

SparkFun Education Tutorials
https://learn.sparkfun.com/

Adafruit Learn Arduino Community
https://learn.adafruit.com/category/learn-arduino

We are grateful for the tremendous support we’ve received from the Arduino community, everyone at SparkFun, and our amazing editors at No Starch Press. The ideas and projects that we’ve assembled in this book are attributed to all of these people and the many whiteboard brainstorming sessions, emails, and side conversations that we’ve had over the past few years. We also want to thank our families—Zondra, Bear, Bridge, Mariela, Mia, and Maeva—for the support that they have provided during the testing, prototyping, and writing process. Thank you!

The SparkFun series is a collaboration between No Starch Press and SparkFun Electronics, an online retailer that sells bits and pieces to make your own electronics projects possible. Each title in the series is written by an experienced maker on the SparkFun staff and edited by the folks at No Starch Press. The result? The book you’re reading now.

The SparkFun Guide to Processing
shows you how to craft digital artwork that interacts with the world around you. With the Processing programming language and a little imagination, you’ll scale detailed pixel art to epic proportions, record and sample audio to create your own soundboard, and create visualizations that reflect changes in sound, light, temperature, and time.