Hardware Reference
In-Depth Information
Wireless and Mobile
Now that you're able to communicate wirelessly, you might
want to make your microcontroller mobile as well. To do
this, all you have to do is power it from a battery. There's a
simple way to do this for the standard Arduino boards, and
there are a few models of Arduinos—and some derivative
models—that are designed for mobile battery-powered use.
The Arduino Fio is great for XBee projects. It has a socket for
an XBee and a battery connector for 3.7V Lithium Polymer
batteries, as shown in Figure 6-18. The mini-USB jack on the
Fio doesn't actually communicate with the microcontroller—
it just charges the battery. To program the Fio, you either
need an FTDI-style USB adapter, as described in Chapter 2,
or you can program it wirelessly over the XBee. Programming
the Fio wirelessly requires an understanding of XBees, so it's
a good idea to program it using a wire first. For more on Fio
programming, see
http://arduino.cc/en/Main/ArduinoBoard-
FioProgramming
.
The simplest option is to connect a battery to the power
input terminals, as shown in Figure 6-17. The Vin pin
(Voltage input) can take from 6-15V input (the Arduino Uno
will run off lower voltage—I've run one off 3.7V—but it's
not always reliable). You can either plug into the ground
and Vin pins, or make a plug adapter and plug into the
power plug.
The LilyPad Arduinos are all made for use in clothing and soft
goods. They're also programmed using an FTDI-style serial
adapter. There are a couple LilyPad power adapters that take
LiPo batteries. The LilyPad Arduino Simple has a jack so you
can add a LiPo battery right to the board (see Figure 6-19).
It's a good idea to keep your microcontroller module
connected to a power adapter or USB power while program-
ming and debugging. When a battery starts to weaken,
your module will operate inconsistently, which can make
debugging impossible.
Figure 6-17
Arduino module powered by a 9V battery.
Figure 6-18
Detail of the Fio, showing battery connector and USB-to-Serial
adapter connected for programming.
Figure 6-19
LilyPad Arduino Simple, with the LiPo battery connector.
Photo
courtesy of Spark Fun.
