I'm quite fascinated with the recent launches of Andy Nguyen VK3YT's (and others) "pico balloon" experiments. What exactly are the payloads he's using to keep things so light. I've researched a couple of Arduino APRS trackers online, but they seem bigger than what he's sending aloft.
Also. What other payloads might be interesting to send aloft as a "test", with or without tracking? Any ideas? How about a simple fox hunt transmitter/beacon or model locator beacon. No Lat/Long tracking but relying on the ham community to track and share the info on a specially designed website.
Just brainstorming here....
73 Larry N2ICZ