PHYSICAL COMPUTING

Additional Documentation

Code for "Parklights"

Memory Issues Associated With "Parklights"
The memory implemented in the Arduino platform is limited. Because of this, storage of mass quantities of data was the most difficult problem faced in this project.
In the case of "Parklights," 5 arrays were implemented for the storage of data (4 for the light states, 1 for the time). For some reason, we could not create an array longer than 42 values (43 would cause the program to freeze up). This proved problematic in the case of storing values during a long period of time.

Passive InfraRed sensors (PIRs)

General Description
PIR sensors are passive electronic devices which detect motion by sensing infrared fluctuations. Once a motion is detected, a high is sent to the signal pin.

Because of the biological characteristic of organisms to emit heat, these sensors work well in detecting human motion and therefore are commonly implemented in security applications.

Sensor Operation
PIR sensors are composed of a solid-state pyroelectric chip. This chip is the heart of the device because it generates an electric charge when exposed to infrared radiation. This charge is then enhanced by an amplifier so the output voltage can be interfaced with other devices. The sensitivity of this device is enhanced by a translucent Fresnel Lens covering this chip.

The "Personal Sphere" utilizes an ultrasonic proximity sensor in order to visualize an individual's own personal space. Even though the size of this space varies from culture to culture and from individual to individual, the concept of personal space is universal.

Our project is a prototypical device that enables the individual to easily engage and advertise multiple magnitudes of his/her own personal space to any individual who penetrates it. Using a potentiometer, the individual is enabled to define the desired size of their own personal space and through the use of a simple LED display, that individual can visually project the borders of this space. Through the LED signifier, different luminous patterns convey a violation of that sphere.

this site has many interesting and inexpensive electronic items:
http://www.goldmine-elec.com/

and light emitting textiles:
http://www.youtube.com/watch?v=Yd99gyE4jCk