In many ways the device worked up to our expectations. Its operation is very simplistic and almost anyone can use it with no technical knowledge at all. The breathalyzer readings are sensitive and accurate, and the pressure sensor works well. We only wish that we were able to getting working model on a separate PC board so that it could be installed. This way we could see its deficiencies and design a new version. The only other complaint was the display. It worked according to its specifications but for instructional purposes, it would be nice to have something larger.
Ideas for Future Design Revisions
There are many other features that could be implemented to improve the device
v More administrative codes
v A method of managing valid codes by a serial port
v BAC readings may optionally be displayed
v An installable device on a PC board
v No balloon, only a place to blow on
v Larger display so that instructions could be more clear
v Logging system so that you can know what time people came in
v Automatic flushing of piping system by fan and solenoid valve
Acknowledgments and Inspirations
We consulted the Breath-o-Matic project from Spring 2004 by Alex Averbukh and Dan Golden. We used the same gas sensor as them and their section on possible improvements gave us some inspiration on our design.
Some of the code used was from our security system lab earlier in the semester.
We would like to thank Professor Bruce Land, and all of the 476 Tas for their help.