[Tim’s] ghoul in the box project has all the elements of a classic Halloween prop. He built it for last year’s display but we’re sure it will be a perennial favorite.
As the name implies, it’s modeled after a Jack-in-the-box toy. Fittingly, it’s decorated with bright, happy colors and includes a crank on the right side of the box. But you don’t need any man-power to make it work. Hidden in the red circle at the center of the front panel is a motion sensor. Walk in front of the box and one of two modes will be triggered. The crank may start up and a happy rendition of Pop Goes the Weasel plays. But as it nears the end of the song the tempo slows and the pitch drops as if running out of steam. It’s perfect foreshadowing for the vigorous bursting forth of the ghoul inside.
The demo after the break gives you a look at the operation, as well as the components used in the build.
Continue reading “Halloween Props: Ghoul in the box puts on a pretty good show”
Last year [Bob] didn’t let the little kids get some candy and continue on their way without giving them quite a fright first. His modified trashcan lures you in and then scares the bejesus out of you.
He calls it Oscar the Trash-bot. The image on the left shows a ghoulish-looking head peeking out of the partially opened lid of the trash can. It has some movement, but is slow and quiet. The small, slow movements catch your eye and seem safe enough. Until you get a bit closer. A range finder triggers when the unsuspecting victim draws near, causing a much bigger, faster, and bloodier beast to pop up and stick out a claw. Check out the two videos after the break. One of them shows the claw mechanism, which is made with the help of a brake cable and shows very realistic and blazingly fast movement. The other is an overview of how the entire setup works.
Continue reading “Halloween Props: Trash can jack-in-the-box”
Behold the electronic Jack-in-the-box. Open the lid or enter the wrong combination and you’ll set off an alarm. But if you get the right 6 combination code entered using the three buttons you’ll be rewarded with a little ditty and the appearance of the Jack (who lives in the box). [Jeremy Blum] designed this as part of his introduction to rapid prototyping class at Cornell University. See his description of the project after the break.
When he shared the link with us he mentioned that this might be a fun project for beginners and we couldn’t agree more. The design is easy to wrap your mind around using the provided schematic. The source code package includes PDF files that contain well commented code segments along with their descriptions. You can use this to get comfortable with driving a speaker and servo motor using an Arduino, as well as to read from two different types of inputs. We are especially interested in the hardware debounce implemented for the switch that detects if the lid is closed. Software debouncing is pretty much the standard these days but because an external interrupt is used to read the switch that method won’t work here.
If you’ve got an Arduino and few of these components why not give this a try?
Continue reading “Beginner concepts: electronic Jack-in-the-box”