An old PC case becomes a Halloween vending machine

Halloween is creeping up on us like some kind of impatient ghoul, which means that half the maker community is currently scrambling to throw together some spooky projects. Those projects become a lot more approachable when you start with something the already exists—anything, really. For example, Appalachian Forge Works began this Halloween vending machine project with an old PC case.

Used PC cases are easy to find for free or at least at low prices, which makes them a good choice when you want a sturdy metal enclosure with plenty of mounting points. In this case, the PC case acts as the enclosure for a small but feature-packed vending machine. At the press of a button, it can dispense prizes (rubber balls in the demonstration), play sound effects, and show animated graphics on a large screen.

Though this is a good-sized PC case that could probably fit a full-size ATX motherboard, Appalachian Forge Works replaced the innards with an Asus Chromebox CN60 computer running Linux. That CN60 is tiny, which left plenty of room inside the case for the other components. Those include an Arduino UNO Rev3 board, a monitor, power supplies, and amplified speakers.

The vending mechanism, controlled by the Arduino, feeds prizes from a hopper on top of the case. A 12V motor rotates a wheel that drops the balls down a chute and to a retrieval cup at the front. A photoresistor and LED perform as a break beam sensor to detect a passing prize, so the Arduino knows when to stop turning the vending motor. After a timeout period without such detection, it stops trying and assumes the hopper is empty.

It may not be the scariest Halloween project we’re going to see this year, but it is perfect for catering to younger trick-or-treaters.