20+ years ago, I was into High Power Rocketry bigtime. I launched rockets at Hartsel, Pawnee, Black Rock, and even sent one to 20K ft AGL off the Bonneville Salt Flats. I also designed and sold altimeter kits that became pretty popular with the rocketry crowd. By the time I left the hobby, there were several hundred of my altimeters bouncing around the skies. Sadly, the Patriot Act drove me away as I got tired of men in black suits bothering me every few months (no, I’m really not kidding).

Passin’ gas. N₂O oxidized propellant launch at Hartsel, CO

When I discovered a good friend had recently gotten into HPR, I was more than thrilled to unload my boxes of rocket parts and pieces that had been taking up shop space for decades on him. He saw one of my old altimeters, he asked if I could build him one. It sounded like a fun project to revisit so I said “sure, why not?” I did a little research and like everything else with time, rocketry had gotten expensive. Unlike my flying days, altimeter / telemetry payloads are now plentiful, tiny… and definitely not cheap! It’s not hard to drop $200 or $300 on a data logging dual-deployment (drogue and main parachutes) model. After hashing out specific feature requirements with my friend, I quickly came up with a plan to do a dual deployment, data logging altimeter using off-the-shelf modules and through-hole parts. Total BOM cost? Under $60. While I don’t have any interest in getting back into the electronic kitting business, this setup should be readily reproducible by other rocketry enthusiasts, so once the dust settles, I’ll just toss it up on Github as Open-source hardware.

Custom board just sent off to JLCPCB… Stay tuned!