How To: Measure Who's the Drunkest (+ Avoid DUIs) with a DIY Arduino Breathalyer

Whether you want to use it to keep your guests safe or just to see who's the most drunk, it's always fun to have your own breathalyzer at a party. We've seen DIY breathalyzers before, like this one by Craig Smith, but how about an Arduino breathalyzer?

Engineering student Daniel Andrade built his with an MQ-3 alcohol sensor, Arduino board, and some LEDs and resistors.

He posted instructions, schematics, and all the code on his blog, so you can head over there if you want to build your own. Watch the video below to see it in action.

Think this is cool? How about a similar version complete with an animation that actually rewards the person with the highest BAC? Meet Geoff G's Squidalyzer, the breathalyzer that encourages you to drink more!

It's connected to a television interface that displays your results via a squid wearing a Santa hat, and it even keeps score so you know who's "winning" (depending on your perspective, that is).

Don't have the time to make your own? You can buy one for your iPhone instead!

Photos by methodshop

It works with any iOS device (though maybe not the new iPhone 5) and can also identify cigarettes and coffee on your breath, making sure that nothing interferes with the alcohol test. The best part? You can snag one for about 25 bucks on Amazon.

I wasn't able to find one available for Android, but you can DIY one out of an Altoids tin with this tutorial by alinke over at Instructables, or buy a kit that comes with everything you need.

No one wants a DUI or an accident, so a breathalyzer is a great little tool to have around that can be both fun and functional. Do you or any of your friends have one? Have you ever used an iPhone breathalyzer? How well did it work? Tell us about it in the comments.