Greg’s “cameleon lamp”, he writes –
Concept: To design a light that mimics a color if shown to it. Design: lamp driver. LEDs are very efficient as they only emit one frequency of light, and because of this the light produced could be perceived as flat and lifeless. Instead i used tungsten bulbs because unlike LEDs they arenâ€™t flat and lifeless. Because the Arduino cannot provide enough current to power a tungsten bulb without damaging the Arduino chip, I had to use transistors to turn a separate power source on to power the bulbs. This also meant that the lamp wouldnâ€™t draw too much current from the laptop. To do this i connected the pwm pins to base of the transistors, and grounded the transistors to the Arduinoâ€™s ground in series with diodes to prevent current flowing back through the tungsten bulbs from the Arduino. Because i used the pwm pins i could dim the bulbs the same way one can dim LEDs in the Arduino code.colour sensor. Because I wanted the lamp to detect colors and mimic them, I prototyped a simple color sensor.
Making furniture interactive – The cameleon lamp Link.