Page 303 - Hacking Roomba

284 Part III — More Complex Interfacing

Making an Arduino Prototyping Shield

Unlike the Basic Stamp Board of Education, the standard Arduino board doesn’t come with a
solderless breadboard attached. This is okay, since they tend to wear out. In fact, it would be
nice to keep a circuit you created by just unplugging it from the microcontroller board when the
inspiration strikes to try something else.
You could use a stand-alone breadboard like in Figure 13-2, and run wires between it
and Arduino. But since this is supposed to go on top of Roomba, it would be better if there was
a way to make a sturdy connection between the two. The Arduino designers have thought
of this and have created a set of shields that sit on top of the Arduino board, plugging in to
its header sockets. This is a great solution since you can mix and match various shields to
solve common problems. Some of the shields that have been created are motor controllers, bio-
sensors, RFID readers, LCD displays, and prototyping. For an up-to-date list of shields, go to
www.arduino.cc/en/Main/ArduinoShields.
The prototyping shields are the most interesting ones for these projects. These were created
by Tom Igoe of NYU’s ITP program. You can download his designs for the shields from
www.tigoe.net/pcomp/code/archives/avr/arduino/.
You also can build your own Arduino prototyping shield out of a Radio Shack circuit board, a
small solderless breadboard, and a few headers. It’s a quick project that will only take a few min-
utes. It doesn’t offer all the capability of Tom’s shields, but it works in a pinch. The steps to make
one are:
1. Take the wire wrap socket and break off an 8-pin chunk.
2. Push it through and solder it down to the edge-most pads.
3. Take an 8-pin header socket and solder it down immediately next to it. Notice that since the
pads are joined, the connection between the two is made for you (see Figure 13-20). If the
header socket has plastic flanges that make it hard to fit, snip them with cutters.

4. If you want the second set of digital pins, repeat Step 3, but lined up with the second Arduino
header socket. Note that since the second socket isn’t exactly inline with the Radio Shack cir-
cuit board, you’ll have to bend the wire wrap pins a little.
5. Use the double-sided tape that came with the solderless breadboard and stick it to the top of
the circuit board (see Figure 13-21).