• Client : Bonita Ely
• Location : Jacaranda Square, Sydney Olympic Park.
• Job type : Technical bridge.
• Year : 2010.
• Team : Rob Largent UNSW, Allan Giddy CoFA, Energy Australia

“Thunderbolt is a temporary public artwork created for the 10th anniversary celebrations of the Sydney 2000 Olympic Games.

“Made from a recycled windmill found in Broken Hill, the nocturnal lighting of this dynamic meta sculpture changes in repsonse to the amount of electricity consumed in the nearby neighbourhood.”

Thunderbolt is a public sculpture piece by Bonita Ely of the The Environmental Research Initiative for Art at CoFA UNSW. Version 1 is installed at Sydney Olympic Park and will run initially for 3 months. The lighting of the structure is powered by solar cells and altered based on the power consumption of the surrounding residents. Long time collaborators Allan Giddy and Rob Largent have put together the lighting control rig, EnergyAustralia have kindly donated their data, and Laudanum have provided the glue between the two.

On site we have a tiny Microclient SBC connected to an Arduino board and a 3G modem. Each of these 3 parts are seriously overspec’d for the the job but are all part of our usual toolchain and were on hand. The lighting rig expects its 5 inputs to be tickled to which it responds with a mix of its 3 lighting colours. So our computer connects to its data source and tells the Arduino to bring up one or more of its pin outs.

In order to work around a couple of techno-political issues (the temporary nature of mobile broadband connections, and who connects to whom, when and how) we elected to move the central data source to Google App Engine. Having done that both the data provider (the company providing our stats) and data consumer (the computer driving the lights) were able to abdicate all the data munging to the App Engine too (which was a boon).

Some GAE gotchas.

• Large XML archives of prior data to pre-populate our database. Fine consumed in small chunks but quickly exceeded the GAE quota
• Unique keys are provided for each `put` in GQL – but you can specify your own key thereby making a UNIQUE KEY field. We hashed together our timestamp and station ID to use as a key. Each time GQL puts with the same key it REPLACES the row. There is also a get_or_insert GQL method which either gets existing data for a keyname or puts new data where the keyname doesn’t exist.

Parts

• Microclient SR
• Huwei mobile broadband USB modem
• Arduino Duemilanove
• Ubuntu, Python, Google AppEngine