Hardware Reference
In-Depth Information
Reporting Toxic Chemicals in the Shop
If you've got a workshop, you'll appreci-
ate this project. By attaching a volatile
gas sensor to an XBee radio, you'll be able
to sense the concentration of solvents in
the air in your shop. When you're working
in the shop by yourself, it's common to
become insensitive to the fumes of the
chemicals with which you're working. This
project is an attempt to remedy that issue.
Figure 7-3
The completed toxic sensor system: sensor, monkey,
and network connection.
The sensor values are sent to two other radios. One is
attached to an Arduino with an Ethernet shield, which
is connected to the Internet as a web server. The other
radio is attached to a cymbal-playing toy monkey, located
elsewhere in the house, that makes an unholy racket when
the organic solvent levels in the shop get high. That way,
the rest of the family will know immediately if your shop
is toxic. If you don't share my love of monkeys, this circuit
can control anything that can be switched on from a tran-
sistor Figure 7-3 shows the completed elements of the
project. Figure 7-4 shows this project's network.
Figure 7-4
Network diagram of
the toxic chemical
sensor project.
Sensor XBee
Radio
XPort XBee
Radio
Monkey XBee
Radio
!
Arduino as
web server
This project is designed for demonstration purposes
only. The sensor circuit hasn't been calibrated. It won't save
your life; it'll just make you a bit more aware of the solvents
in your environment. Don't rely on this circuit if you need
an accurate measurement of the concentration of organic
compounds. Check with your sensor manufacturer to learn
how to build a properly calibrated sensor circuit.
Internet
