Halloween Decorative Door

This project was designed by another student and me, where we designed, built, and refined a decorative Halloween-themed door. Our main objectives were to design a mechanism that could dispense an individually wrapped candy while also authenticating users to ensure only one candy was taken.

Visual Design/Blacklight

The front side of the door is purely for aesthetic purposes, with ultraviolet-reflective tape designs being illuminated by a blacklight mounted above the door. Although the blacklight was powered via 120V, we designed and laser cut a bracket that allowed an SG90 micro servo to be fitted to the power switch. This allowed us to control the on/off state via the ESP32 microcontroller without modifying any 120V wiring.

User Identification

On the left side of the door is a 3D printed housing that encases an MFRC522 RFID reader. When a student scans their student ID card, the microcontroller will ensure that the card is a genuine school ID and the user has not scanned it before. Other chip-based cards will not work. If both of these conditions are met, the LED illuminates green and the door will dispense candy. If not (e.g. the student attempts to rescan their ID), a red LED is illuminated and an audible message is played over a speaker notifying the student that their scan was denied. Our initial testing showed that some people were confused about the door usage. To refine this process, we illuminated the NFC reader and placed a reflective square on the ground/dispensing mechanism. This improved visibility and made the usage more intuitive.

Candy Dispensing

The candy dispensing is a multi-part sequence. The blacklight is turned on to illuminate the door, and a randomized Halloween song is played on a hidden speaker via a DFPlayer Mini MP3 Player. Then, an MG996R rotates the candy mechanism to dispense a Starburst candy. On the inside of the door is a sleeve that is filled with candy. Each time a valid card is scanned, a new candy drops down and is pushed outside the door via the rotating mechanism. This design allows the candy to be secure and easily refilled from inside the suite.

Demo of Final Design