Mess Token Counter

About this project

Build a slot-mounted token counter for a hostel mess counter that automatically counts every paper or plastic meal token slid through a narrow gap, without a camera, barcode, or app. A slot-type photointerrupter sensor — an IR LED and phototransistor facing each other across a small gap — detects the beam being broken as each token passes through, while a software debounce-and-gap algorithm rejects a single slow or fluttering token from being counted twice. A 16x2 LCD shows the running total against a configurable daily quota and a live 'tokens per minute' throughput rate, with a buzzer and red LED warning the moment the quota is reached. The WOW moment: slide tokens through one at a time at different speeds — fast, slow, even a slight flutter — and watch the counter increment exactly once per token every time. Build time: 2-3 hours. Fully offline, no WiFi, no app, no cloud.

What you get

• Complete, commented source code
• Full components list with quantities
• Pin-by-pin wiring guide and connection table
• Step-by-step upload and testing guide
• Project report (.docx, IEEE style)
• Presentation slides (.pptx)