The Smart Candy Pumpkin is a motion-activated Halloween candy dispenser built by two 17-year-old students from Switzerland. Place your hand inside its mouth and a servo-driven wheel automatically releases a handful of sweets — no button press needed. An HC-SR04 ultrasonic sensor continuously monitors the inside of the pumpkin mouth. When the detected distance drops below 15 cm, the ESP32-S3 triggers a servo rotation that spins a 3D-printed candy wheel, dropping a portion into waiting hands. The system then resets and waits for the next trick-or-treater. **Hardware:** - Microcontroller: ESP32-S3 Dev Board (N16R8) - Actuator: SG90 or MG90S micro servo (GPIO 14) - Sensor: HC-SR04 ultrasonic (TRIG GPIO 16, ECHO GPIO 15) - Power: 10000 mAh Li-Po → TP4056 charger → MT3608 DC booster → 5V - Charging: USB-C (TP4056 HW-373 module) **3D Printed Parts (8 pieces, ~800g PLA, ~22h print time):** Bottom Base, Inner Cover, Mid-Mouth Section, Upper Mouth Section, Candy Funnel Top, Stem Cap, Servo Wheel, Alignment Connectors (×6). All STL files are attached. **Bill of Materials (~25–40 €):** ESP32-S3 dev board, HC-SR04 ultrasonic sensor, SG90/MG90S servo, TP4056 HW-373 charger, MT3608 DC booster, 3.7V 10000mAh Li-Po, mini toggle switch, round D6×2mm magnets (6–8), PLA filament (orange, green, black). **Attribution:** by merlin-rce on GitHub. Originally published on Instructables and MakerWorld. Licensed CC BY-NC-SA 4.0 — free to share and remix for non-commercial use with credit.
Category: Other Robots