Cat Prank is hidden somewhere in your friend's house, say under the sink, then meows gently. Your friend starts searching for the source of the meows - "why are there kittens in my kitchen", they think. Then when they open the cabinet door a loud snarly cat greets them with a jump scare!

The keyfob remote activates the meowing so you can be far away to make the setup not obvious.

The loud snarly cat is activated by either the light sensor detecting going from dark to light (opening a cabinet door) or from the PIR motion sensor (walking around a corner).

There is a USB port to charge the battery on the back. The sides show two LEDs to indicate charge state.

The electronics are straight forward and hand soldered. The top right is a XY-V17B sound module that plays .wav files from an SD card. The microcontroller is a atmega328p in the Arduino Mini formfactor. To the far right is a 18650 Li-Ion battery and it's TP4056 charging board along with a DC-DC boost to go from 1 cell Li-Ion voltage to 5v.

Under the electronics tray is the speaker, volume pot, PIR, and photoresistor.

Example place to hide the Cat Prank

The frame was designed in AutoCAD and laser cut on a home DIY 40w CO2 laser engraver.

Parts were designed in Tinkcad (don't laugh, lol) before I found non-exorbitant 3D CAD software.

Cat tax (that's Zoey)