Arduino-Powered Going Away Gift

    Recently, one of my coworkers departed the office.  He's one of those folks who rails against the Arduino -- in his opinion, Arduinos are overkill for almost everything, people just need to get back to op amps and 555 timers, dag nabit!  So of course when we learned he was leaving, the entire office agreed -- his going away gift had to include an Arduino and it had to be used in a way that seemed like as much overkill as is humanly possible.  Given that the normal going away gift for our office is a challenge coin, here's what I came up with:

Challenge coin replaced with silver dollar in this photo.

Its a challenge coin with a blinking light.   Flip the coin over and...

Behold the power of the Arduino Micro!

…an Arduino Micro!  At first glance, it's all of the majesty of an Arduino used, essentially, to alternate the voltage value on a pin between high and low, switching an LED on and off.  Of course, I couldn't let all of that horsepower go to waste, so read on to find out what easter eggs I managed to cram under the hood.

Arduino Controlled Halloween Light/Sound/Smoke Effects

    As mentioned in the previous post, I had been working on some Halloween effects with the kids this year.  The last post discussed the digitally controlled smoke machine I created to make this project possible.  This post seeks to discuss the rest of what we put together.

Overview

    Using an Arduino, we were able to set up an IR beam to act as a motion detection trigger.  When the beam between the two is unbroken, the Arduino controls an AC socket, powering a friendly Jack-o-lantern and porch light.  Once the IR beam become broken, the Arduino:

• kills power to the AC socket, extinguishing the lights,
• starts the smoke machine, and
• sends a message to my MacBook, causing the MacBook to start playing back spooky sound effects.

After a delay of 3 seconds, the Arduino:

• turns on LED circuits 1 and 2, lighting up the eyes of an evil looking Jack-o-lantern.

After a delay of 27 seconds (total elapsed time is 30 seconds), the effect is considered over.  Correspondingly, the Arduino:

• turns off LED circuits 1 and 2,
• stops the smoke machine, and
• turns power back on to the AC socket, lighting the friendly Jack-o-Lantern and porch light back up.

To whet your appetite,  I've included a clip of our first test in the basement of my house.  A discussion of how to build the system starts after the jump.