A The XBee ZB radio module (aka Series 2) speaks the ZigBee protocol. ZigBee is great for home automation projects. It’s secure and inexpensive but most importantly it’s a mesh network — a network that can extend its range using other radios intelligently and automati- cally. For example, if your garage is too far away from your gateway you can simply add another radio in the middle to facilitate the wireless connection. To connect to your garage door circuit from the internet, you’ll use Digi’s ConnectPort X2 ZigBee-to-Ethernet gateway. The ConnectPort X2 can be programmed using the Python language. We used an open source Python application called the XBee Internet Gateway (XIG) to create the link between our garage door and the internet. You could also connect an XBee to a PC in order to make this link, but he ConnectPort X2 uses a lot less electric- ity and is always ready, so you won’t have to worry about forgetting to start a PC applica- tion in order to connect to your garage door. (If you wish to explore using the PC version, visit code.google.com/p/xig.) Finally, you’ll set up your mobile phone to communicate with your garage door from
anywhere in the world. Scott Kilau created a
beautiful open source Android mobile application, and Margaret McKenna created a web
version that people can use to turn any smartphone into a garage door remote.
the XBee pins to the breadboard’s 0.1"
spacing. Just follow the instructions and
schematics online at makeprojects.com/
project/x/1871 and check the materials list at
goo.gl/Lue81. This is a simplified design that’s
intended for prototyping, not permanence.
For permanent installation, we recommend
using our custom printed circuit board (PCB),
the XBee Pulse I/O Board (Figure B), which
is described at jordan.husney.com/xbpio.
It’s open source too — feel free to make your
own. For security it adds static protection on
the sensor inputs, and a circuit that stops the
garage door from being toggled in the event
of a power outage. Assembly is simple: find an
empty spot on the PCB and note its silkscreen
label (e.g., capacitor C6). Locate each item in
the materials list online and solder it in place,
taking care to orient it correctly. Don’t solder
down the XBee module — use the 10-pin
headers, so you can remove it if you wish.
1. BUILD THE XBEE PULSE I/O DEVICE
For this project my collaborator Andy Warner
and I created a simple electronic device to
use for all kinds of automation and monitoring
tasks. It simulates pressing and releasing a
button, and it also routes inputs and outputs
to an XBee radio. We call it the XBee Pulse I/O.
It’s open source hardware: use our design,
improve it, sell it to your friends, or give it
away to win over your enemies.
For a weekend project, you can build the
device on a solderless breadboard (Figure A),
using a small XBee breakout board to adapt
68 Make: makezine.com/30