Maker [Dino Segovis] has started on a project he calls “Hack a week” where he will be putting together one hack or project per week, for a full year. The first installment of his video series was finished just two days before April Fool’s, and appropriately enough covers the construction of a circuit you can use to prank your friends.
The “Altoids Screamer” is a simple circuit based on a 555 timer that he built into a standard Altoids Tin. The 555 timer is used to generate a loud pitched squeal whenever the tin is opened. This is accomplished by wiring up the 555 in astable mode, and connecting it to a speaker to output the sound. A micro switch is installed inside the tin to detect when the top has been opened, triggering the “scream”.
While it’s not the most complex circuit we’ve seen, it definitely gets the job done and is easy enough to build in time for tomorrow’s festivities. It is a great hack for the office, the library, or any other quiet place.
Continue reading to watch [Dino’s] first Hack a Week video demonstrating the prank’s construction. If you are interested in some more of his work, be sure to check out this automatic ball launcher and this other 555 Screamer toy.
[youtube=http://www.youtube.com/watch?v=q8fqwOllRVI&w=470]
Hack a week – nice idea. I’m not a fan of this first project but will keep an eye on his site :)
Forgive my ignorance, but what purpose do the 555, resistors, and capacitors serve? I’ve made a nearly identical device (in an altoid tin even!) with just a switch, battery, and piezo speaker.
At least it didn’t require an Arduino.
@carl:
It generates the audio signal; a square wave.
I don’t believe that applying a constant voltage should cause any effect.
Anyway, in regards to the actual video, I’m slightly disappointed. It’s a 555 timer in a pretty conventional astable configuration with a speaker hooked up. Common, basic, not all that interesting.
I’m sure it can’t always be utter brilliance if you’re forcing yourself to build something in such a short time, but the deadlines are self-imposed. I think we would rather see quality than sheer volume. It would be OK with me if a project wasn’t taken from start to completion each week. Why not just start something a little more substantial or experimental and give a little update each week. I think one thing we don’t see often enough is the design _process_.
Regardless, the hack-a-week video blog is a really cool idea and I’d definitely like to see more of it.
Damnit! I actually just came up with this idea yesterday, but mine involved a photoresistor such that when you opened the mint tin, the frequency changed from low to high as more light entered. This would give it a pretty cool growling to screaming effect. At least that’s the idea. You could design it such that in darkness, it clicks away eluding to something being in the tin… then when you open you get a nice surprise. I think I’ll still build mine… I have one too many 555’s and altoids tins laying around ;-)
@Brett W.
Hey that light sensing thing sounds like a good idea, you could you it in a game of “Blind Man’s Bluff”, a blindfold, a flashlightn and an empty room.
@carl, @r_d
Indeed Carl, your version would be simpler.
There are some (many?) piezo buzzers that self-oscillate as well as the ones that behave like speakers and need an AC input.
The 555 allows you to chose a specific tone though, and it might be easier to find a loud speaker than a buzzer
I wonder where I found the name for his website.. it seems so familiar to me..
After being inspired by this post.. i went the the Shack, found a slightly different yet quicker to assemble version. The Shack carries a 102db piezo siren (12v) add a micro lever switch and a soldered in 23A battery. The all fit into the tin taking about 2/3 of the width, leaving enuff space for a few altoids to rattle. Also very close to the weight of a full tin of mints. I just twisted the wires and held everything with hot glue. 15 mins assembly time.
So liking the variations on this. :) Part of the reason I’m doing a hack a week… to inspire.
Hack A Week won’t be all things to all people, but it will be lots of fun.
Dino
@r_d @Jonathan
Thanks, I didn’t realize the difference in speakers/buzzers.
I like that there are so many different possibilities for this project. Maybe a flashbulb or some leds?
could use two transistors or so
I just wanted to follow up on my claim of the idea I had. Please see my light sensitive Growl & Scream Altoids Prank here:
http://hackaday.com/2011/04/03/adjustable-prank-box-growls-and-screams/