My previous article “Weather Balloon Tangent Project – Surveillance Camera!” shot a wrench into the Weather Balloons gears. Well, not really a wrench, more of a change of direction. The planned Pelican case turned into a wooden box, and the expensive GPS module was replaced by 6 AA batteries.

The theory here was that sealed Pelican case would pressurize at altitude and possibly burst. Replacing it with something wooden would allow the interior to equalize with the atmosphere. Also, since I made it last week, it was ready to go. No fussing with again recreating packaging.

And the GPS module went away as it was proving to be more expensive than anticipated. I choose to instead increase the battery capacity of the phone, allowing it to complete it journey without dying, helping me locate it once it touched down. 6 AA batteries were wired in series to maximize run time. And a +5VDC regulator was wired in so the pack could be directly connected to the phone’s USB port.

Also considered as the wooden box was not the best in terms of insulation (high altitude is cold) was a small 5V heater. Keeping the phone (specifically the phone’s on-board battery) warm might help after a flight, when the phone falls back to the ground and needs to connect to a cell network, so that I can find it. This was ultimately decided against as the power consumption was too high at levels approaching 1A.

The final configuration was fairly simple. Keeping things simple and low cost. Here’s how it looks, balloon deflated of course.