Parting is such sweet elation.
Elevation change per 0.15 meters (0.5 foot) measured by BMP180 triggers relay state.
Good riddance, Arduino 101. May your gibberish never stain my IDE again.
1. Project worked to perfection--right up until the balloons were purchased. After having not acquired enough balloons (12) for lift, a stripping down of materials and conversion to a lighter 12 volt battery resulted in an accidental overload and in brief - kaput! Secondary to this, let it be known that filming string hung peripherals and balloon flight at night with low budget production is as impractical as this whole venture.
2. 1 liter of Helium lifts 1 gram. 12" latex balloon volume is 15L. Horse shit!