When everything is working, a child walks up, waves at the sensor, the twin eyes on top swivel round, and a box of Nerds drops onto the tray. The whole thing runs on a Raspberry Pi 5, and the wave is picked up by a custom machine learning classifier the maker trained as a personal development project. There is also a hand landmark detection model that wakes the system when someone approaches.
The construction side is impressive. The internal dispensing mechanism was modeled and 3D printed by the maker, and the housing is an upright cardboard box with Nerds graphics on a wooden base, complete with a slide-out ramp and orange suspension straps. Two robotic dual-lens eyes in a WALL-E style tilt on servos above the box, a tablet overhead shows a live camera feed of trick-or-treaters, and a printed sheet on the front tells visitors to wave, wait, speak and collect.
Capacity is serious: 180 Nerds boxes spread over 5 banks, and the maker gave away 300 boxes in 2 hours. A backup bucket of regular candy sat alongside, and only 10 pieces came out of it all night, 9 of those going to kids who had already received a Nerds box. Just one child declined to use the dispenser at all.
The one hiccup came when a wire on the time-of-flight sensor came loose during the second trick-or-treater's visit, and the dispenser dumped multiple boxes. The maker plans time-based logic to handle bad sensor readings. Amusingly, children loved the box dump so much that a jackpot feature is now planned, maybe 1 in 50 or 1 in 100 visitors, though the odds are still undecided. Supporting it would take at least 5 to 10 more candy banks.