From NERF Dart to Flight Data
This project started with a bold challenge: create the smallest avionics card in Olin Rocketry history—small enough to fit inside a large NERF dart. Why? Because if we could fire our avionics out of a toy gun and still log reliable flight data, we would have the perfect testbed for future rocketry code.
After several rounds of iterative design, we landed on a compact SMD board that not only fit the dart but also became Olin Rocketry’s very first fully surface-mount avionics unit, setting a new standard for size and efficiency across the team.
Purpose and Functionality
The board was more than just small—it was powerful. Packed into the tiny form factor was a 9-axis LSM6DSO IMU for motion and orientation tracking, a BMP390 pressure sensor for altitude measurement, and a radio module for Bluetooth/Wi-Fi communication. An SD card handled onboard logging, while a built-in charging circuit kept the battery reusable. Together, these components gave us real-time telemetry and detailed post-flight data, transforming a toy dart into a serious testing platform.
Mini Avionics Schematics:
Mini Avionics PCB:
Coding the Brains
I developed the avionics software with flexibility in mind. At its core was a Kalman Filter–based sensor fusion system that combined IMU and pressure data into a smooth, accurate state estimate. The modular code structure meant it wasn’t just for the dart—it could serve as a testbench for any future rocketry avionics. I also wrote dedicated classes for wireless communication and battery management, ensuring the system could run safely and transmit critical data in real time.
Impact on the Team
This “mini avionics” board proved that size doesn’t limit capability. It gave Olin Rocketry a fast, repeatable way to test algorithms and electronics before integrating them into full-scale rockets. By shrinking avionics down to the size of a dart, we gave the team a tool to validate code and collect data on demand—paving the way for smarter, faster, and more reliable flight systems.
