I designed this machine to assist with my high school physics assignment.

When you press the button, a servo opens and a stopwatch starts. Once the distance sensor sees an object within a certain range of it, the stopwatch ends and the LCD displays the amount of time it took for the distance sensor to see the object after the button was pressed.

I am next going to build a ramp that can be covered in different materials (such as sandpaper and tin foil) which I'm going to roll an object down. I am going to use a servo as a gate to release the object and the sensor is going to tell me how quickly the object reached the bottom. This allows me to work out which material had the most friction.

EXPANDED TECHNICAL DETAILS

High-Speed Temporal Tracking

This project creates an automated, non-contact stopwatch system, ideal for timing athletes, RC cars, or gravity experiments.

• PIR/Ultrasonic Triggering: Uses a HC-SR501 PIR sensor or HC-SR04 ultrasonic sensor to detect the start and end of an event. The Arduino captures the exact timestamp using the micros() function for sub-millisecond precision.
• Real-Time LCD Dashboard: Displays the "Current Lap" and "Best Time" on a 16x2 I2C LCD. The firmware handles the calculation of elapsed time ($\Delta t = End - Start$) and formats it into MM:SS.mmm.

Reliability

• Debounce Logic Matrix: Includes a "Cool-down" period after a trigger to prevent false starts due to sensor bounce or erratic motion during the detective phase.