A Slot Machine for Cats That Pays Out in Treats

It doesn’t really take much to entertain a cat. We may like to give our pets elaborate toys, but it’s the boxes those toys come in that capture their interest the most. For reasons unknown to us humans, cats prefer an empty paper bag over a robotic mouse or an automated laser pointer.

That didn’t stop CircuitCindy from trying to impress her cat with an over-the-top toy she built. Who knows? Maybe it will work. Perhaps we just haven’t stumbled on the right formula yet. Maybe cats like to gamble? There are all of those pictures of cats playing poker, after all.

The only way to be certain is to give it a try, so CircuitCindy built a kitty slot machine. Cats pull the lever, and if the spinning reels line up just right, they are rewarded with a treat. After a certain number of unsuccessful tries, the machine will have mercy and dispense a treat anyway to keep kitty happy.

The machine is powered by an Arduino UNO R4 WiFi, paired with a CNC Shield V3 and three A4988 stepper motor drivers. Each driver controls an individual reel, allowing them to spin independently just like a real slot machine. The reels themselves feature multiple symbol positions — everything from fish to paws — and are carefully calibrated so the system knows exactly how many motor steps correspond to each symbol.

When the lever — connected to a microswitch — is pulled, the system decides whether the spin will be a win or a loss. In normal operation, each reel stops at a random position, usually resulting in mismatched symbols. But if the internal “pity counter” reaches a preset threshold, the machine overrides randomness entirely, aligning all three reels to guarantee a win. It’s a mechanic borrowed straight from modern video games, adapted here to prevent feline frustration.

To make the experience feel authentic, the reels don’t simply rotate into place. Each one spins through multiple full revolutions — 10, 12, and 14 respectively — before slowing down and performing a subtle jitter motion to mimic the clunky mechanical settling of traditional slot machines. It’s a small touch, but one that adds a lot of character.

When a winning combination appears, a separate subsystem takes over. A DC motor, controlled by a Cytron MD10C driver, rotates a disk that dispenses a single treat. The motor briefly reverses afterward to prevent jams, ensuring consistent operation over repeated plays.

With Arduino Cloud integration, CircuitCindy can remotely monitor and adjust variables like the pity rate using a smartphone dashboard to tune the machine’s generosity in real time.

Whether or not cats truly enjoy games of chance remains to be seen. But as far as inventive pet projects go, this one raises the stakes — literally.