Home » Smoke » Hardware Design

The bits and pieces

How could we communicate from a sensor on the outside of a window to a display inside? How would we develop the video presentation?

The Window Problem

The smoke sensor needed to sit outside a window, and we didn’t want to run cables to connect them, so we decided to power the sensor with a battery and communicate the data through the window using an LED on one side and a light sensor on the other.

The sensor was originally held to the window by magnets, but they proved to be too weak to hold the sensor up on the thick double-glazed exterior glass panes. Instead, we modified the sensor for the show and mounted it to the window with a camera suction mount, which allowed us to set up and take down the sensor easily, without altering the building in any way.

The Gas Sensor

The gas sensor itself is a general-purpose sensor for detecting airborne contaminants such as carbon monoxide, ammonia and other gases. An unintended effect of our choice of sensor element is that it detects alcohol fumes, and so can be operated (without smoke) by the breath of an intoxicated person!

Arduino Board

We chose the Arduino board because it allowed us to quickly update our sensor firmware, communicate robustly to the G5, and use the same cable for power and data.

Software

Max/MSP/Jitter was used to perform the video manipulation. We chose it because it is a stable and easy to use environment. The video processing ran on a Macintosh G5 tower.