Karman Project - Telemetry
Live In-Flight Data
Even as CTO of Project Karman, I still like to delve into projects that really interest me. One subgroup that I led and spearheaded development on was the Telemetry group. The goal was to create a telemetry system; live data feed from the rocket to a ground station, including altitude, velocity, acceleration, temperature, and GPS position to monitor the flight.
The need for such a system arose after the loss of our previous rocket. We believe the crash was caused by the failure of our avionics bay under 60g loading and an experimental parachute system. Without any recoverable data though, it was hard to pinpoint the exact cause of failure. This system allows for live rocket updates, up to twenty times a second.
One completed sensing board with three breakout boards assembled in the rocket
I designed the e-bay to be 3D printed and fit in the exact profile of the Von Karman nosecone, acting as a secure body to mount the electronics.
My teammates and I laid out the wiring schematics as well as collaborated on how the micro controller program would work (running C code on a Teensy micro controller). While I was not the primary coder on the project, I did contribute design theory on how the program should function.
Once the master wiring diagram was complete, I meticulously soldered the connections between our eight sensor boards on three prototyping PCBs. Precision was essential to avoid burning the insulation off of the tiny 28 gauge wires. And while it was harder to work with, I elected to use 28 gauge ribbon cable as it keeps the wires much more manageable down the road.
After final assembly the telemetry system is fully operational, and is waiting for a launch window to test on the newest Project Karman rocket.
My vision is to turn this telemetry project into a modular system for other team members to use if they want telemetry in their rockets. I plan to break the code into optional segments depending on the sensors they want to use, as well as construct an independent ground station that is capable of displaying the flight path of the rocket and other sensor data.
Left: Backside of one of the sensor boards that I created. I went for a very clean layout, making sure not to create electrical shorts or damage the small wires.
Right: bottom section of the avionics bay. Securely seats three 2S lipos for redundant power.
Above: Completed telemetry system in new avionics bay
"Final" Iteration
This electronics system was never tested in a launch (parachute systems for the particular rocket were not ready for 8 months). In that time I got really interested in electronics and created my own PCBs based off of the architecture of this system. Those boards did in fact fly twice and worked successfully! Click on the image of the boards to the left to learn more about that particular project.