HW1 // NIGHTLIGHT

Following tutorials from the web and your books is a great way to learn and get ideas. Tutorials are frequently referenced and adapted for larger, more serious projects.

Learning Goals:• Exposure to online resources, methods of searching.• Exposure to the terminology and language of electronic components and their connections.• Hands on experience with a few simple components (discussed in class) and one new one. • Make something practical and simple, yet adaptable for a larger project. • Learning to read a circuit diagram.

Task:Follow this tutorial from Evil Mad Scientist labs:http://www.evilmadscientist.com/article.php/nightlight

In this lab, you will build a simple, dark-detecting circuit that turns on a 10mm LED when the lights go out (aka, the “nightlight” problem). The circuit uses a phototransistor to sense the amount of daylight and an NPN transistor to switch the LED on or off. It is powered by a small, cheap 3V Lithium Ion coin cell battery. In itʼs soldered form it is small, compact and discreet. You can add a magnet to it, and turn it into a “throwie”. Many dark-detecting “throwies” could make a symbol or image appear at night on a bridge or overpass.

Components Needed:• CR2032 coin cell battery (3v) *• LTR-4206E Phototransistor *• 10mm LED• 2N3904 Transistor (Standard NPN Transistor)• 1kΩ Resistor

*Supplied by instructor. The rest should be purchased on your own at a Radioshack or other electronics store.

Notes:• Read the whole article carefully – follow the links, read the comments. Even if itʼs too

advanced, the information provided will give you exposure to the language & dialog of physical computing.

• Watch the “throwies” video, by Graffiti Research Labs.• If you are struggling, you donʼt have to solder the nightlight together. Building it on a

breadboard is sufficient, but it has to work.

Due on your desk at the start of class, Wednesday, September 7.