Krieger Dreamer Peeper
The Krieger Dreamer Peeper, along with its accessory, the Brain Machine Mask, were props for my Halloween 2016 costume as Krieger, the mad scientist of the television series Archer. The presentation would go as follows: a volunteer closed their eyes and donned the brain machine mask, which caused them to see abstract patterns on the back of their eyelids. This was the "dream" - a vivid hallucination that was hard to explain to the audience afterward. Once the volunteer was dreaming, I would life the peeper and point it at their left ear. I then turned the peeper on, and it created a sound effect for "homing in on the dream center of the volunteers brain". After about 14 seconds, the sound effect climaxes, and twenty 10-watt LEDs flash brilliantly as "the dream condensate is pulled out through the volunteer's ear". At the same time as the light flash, a squirt a bit of water out the end of the Peeper into the volunteer's ear. ("That was the dream condensate!") Once everybody has calmed down, a robotic-sounding "analyzing..." comes from the Peeper, then "Dream audio reconstituted. Playback now". Finally, the Peeper plays a short audio clip that is allegedly an excerpt from the dream that the volunteer was having.
An ATTiny85 to drive twenty 10W LEDs and a 120W speaker. Creates ~14 seconds of science-fiction sound effects, then flashes the lights in a brilliant, dazzling flash. Also includes a squirt gun to startle the person it is pointed at. The LEDs and speaker are driven from 2 pins of the ATTiny. I wrote a couple of loops that drive some cool-sounding square waves to the speaker. At the end of the sound effect, the LEDs light for 1/20 of a second, producing a brilliant flash of light.
The LEDs and speaker are driven from the ATTiny by logic-level MOSFETs. The whole thing is powered by a small LiPo battery.
I programmed the ATTiny using my Arduino Duemilanove and these two excellent guides.