My EGR 121 Summer Project: Ultrasonic Tape Measure

This summer in EGR 121, I dove headfirst into building a non-contact measuring device that merges hardware, code, and data analysis into one neat prototype. Armed with an HC-SR04 ultrasonic sensor, an Arduino Uno, and a thirst for precision, I set out to convert time-of-flight pulses into accurate distance readings. From initial block diagrams to final calibration tweaks, each step pushed me to think critically about signal noise, timing accuracy, and real-world usability.

After sketching a clear block diagram trigger pulse, echo capture, distance calculation, serial output I breadboarded the circuit and wrote my first Arduino sketch. Leveraging the pulseIn() function, I programmed microsecond-level measurements and built in averaging loops to smooth out errant spikes. Filtering out spurious echoes proved tougher than expected, so I implemented simple outlier rejection and temperature compensation to keep results consistent across different environments.

Testing became a game of precision and patience. We pointed the sensor at flat walls, curved bottles, and even soft fabrics, logging well over a hundred measurements per surface in Excel. On rigid walls, we achieved an average error of just 0.5 cm with a standard deviation of 0.2 cm. Curved surfaces saw errors around 1.2 cm, and soft, irregular materials hovered closer to 2.8 cm. With calibration tweaks, our accuracy on solid objects improved by nearly a third, consistently landing within 1 cm of the true distance.

Beyond numbers, this project sharpened my problem-solving muscles. I learned to iterate swiftly, every failed reading was a clue, not a setback. Writing modular, well-commented code became second nature, and I leaned on Excel’s charting tools to visualize trends and justify calibration choices. Presenting our findings solidified my ability to translate technical work into clear narratives, both in slides and written reports.

As the semester wraps up, I’m gearing up for my junior year of high school with an exciting twist: I’m simultaneously enrolled in Germanna Community College’s Associate of Science in Aerospace Engineering program. By the time I walk the high school graduation stage, I’ll also be earning my A.S. degree in Aerospace Engineering. Balancing high school and college coursework means strict time management, weekly planning sessions, Pomodoro study blocks, and active collaboration with peers and mentors in both settings.

Looking ahead, I’m already dreaming up enhancements: integrating laser distance sensors for sub-millimeter precision, designing custom 3D-printed mounts in Fusion 360, and even mounting the system on a mobile robotics platform for dynamic measurements. Stay tuned as I continue to explore the intersection of high school, college engineering, and hands-on design, because the best learning happens when you’re always pushing the boundaries of what you think is possible.