Two-way powered microcontroller-based plastic bottles ‘drop-and-tap’ reverse vending machine with stored value system using radio frequency identification (RFID) scanner technology

To help address Metro Manila's garbage problem, the researchers constructed a Reverse Vending Machine to help promote proper waste management system inside Colegio de San Juan de Letran. At the heart of the system is a microcontroller which directs the operation of the various input (sensors and keypad) and output (display and motors) devices attached to it. The machine accepts plastic bottles and credits these as points, which in turn, can be used to buy products. Operation of the machine exhibited accuracy in recognizing RFID accounts, distinguishing between plastic and non-plastic bottles, storage or updating of points of each account, and dispensing products. The machine was able to run on either commercial power or solar power. The addition of the solar panel and battery not only provides a renewable source of energy but also serves as back-up power in the event of commercial power outage. Survey results showed that the Colegio accepts the idea of having a Reverse-Vending Machine and believes that the adoption of the machine will improve the current waste segregation scheme of the Colegio.