THE CANARY
The Canary is a handheld device for monitoring a suite of environmental factors including general air quality, humidity, temperature, and sound and light levels. It is designed with the goal of bringing sensing technologies to a broader audience and, in the process, fostering technological fluency and new understanding of the environment.

In addition to sensing capabilities, the Canary has motor parts, a piezo buzzer, and a full-color LED-all of which respond to sensor values. Using the Canary, people can rapidly produce tangible interfaces, kinetic sculptures, and interactive spaces that are coupled to the environment.

The Canary device is based on the versatile Atmel Atmega168
programmable microcontroller, a popular IC for low-cost embedded applications. The Atmega168 has eight analog inputs used for reading environmental sensors, a UART for serial communication with an external computer and for displaying text to an LCD, and about a dozen general purpose digital I/O pins that are programmed for controlling the servos, LED, buttons, and buzzer. The Canary uses a number of different circuits that sense light, temperature, ambient noise, air pollution, humidity, and pressure. The light and temperature sensors are based on simple (and cheap) components which vary resistance based on an environmental stimulus. The Canary obtains values for humidity and pressure by using off-the-shelf integrated circuits that output a voltage value which linearly maps to the stimulus. The ambient sound level is found by combining a microphone, a simple one-transistor amplifier, and a software filter running on the Canary's firmware. Finally, air pollution is determined using the Dart Sensors Air Quality Sensor; this sensor is based on fuel cell technology which outputs a small current based on the presence of certain air pollutants. A current to voltage amplifier converts the current into an output voltage which can be read by the Atmega168.

WHY IS IT CALLED THE CANARY?
Besides being a cute name, the canary calls to mind the role of the canary in the coalmine. Coal miners used to bring caged canaries down into the coalmines to test the quality of the air. Because canaries have sensitive metabolisms, they would quickly die if the mines were filled with carbon monoxide or methane gas.  If the canaries died, the miners knew they had to immediately leave the mine. Essentially, canaries were the earliest embodied sensors; they dramatically made the conditions of space visible and known.

Our goal with the Canary is to create a toolkit that participants can use to create their own dramatic representations of the environment&ndash (but no animals will be hurt in the process!)