Make Your Own Taxi Fare Meter

The Make Your Own Taxi Fare Meter system operates by translating physical vehicle wheel rotations into readable distance and fare metrics via an Arduino Uno. At the heart of the sensing mechanism is an inductive proximity sensor (PNP normally-open type), which detects metallic targets or spokes passing by on a rotating wheel without physical contact. Each time the sensor detects a passing target, it generates a discrete pulse signal. Because industrial inductive sensors often operate at higher DC voltages, a diode D1 and a properly configured resistor network—including pull-up resistor R2—are integrated into the interface circuitry to safely condition the incoming signal and protect the 5V logic pins of the Arduino Uno from higher-voltage transients. Switch S1 allows the user to manually control system states, such as resetting or toggling display menus. Once the conditioned pulse signals reach the digital inputs of the Arduino Uno, the onboard microcontroller executes a custom program written in the Arduino IDE. This software script tallies the total pulse count, applies a mathematical conversion factor to translate rotations into linear distance, and continuously calculates the cumulative fare based on distance traveled. Finally, the real-time calculated distance and monetary fare are outputted to a 16x2 LCD display, providing a clear visual readout for passengers and drivers alike. All discrete electronic components are securely mounted and interconnected on a single-side PCB, ensuring a compact and reliable hardware deployment.