Letten is a place at the Limmat river right behind the ZHdK building in Zürich.

The project idea is described here:

http://makeopendata.ch/forum/discussion/5/physical-mashup-of-a-multicolor-led-and-the-current-water-temperature-at-letten-environmental-data

The aim of OpenLetten is to show how hard it is to parse data if the publisher choses a human readable (here PDF ) data format, and how easy it becomes to build novel applications once the data is (re-)published in an open, machine readable data format (e.g. CSV or RSS ).

• http://www.hw.zh.ch/hochwasser/mac/at/0851.PDF (Source data, PDF )
• https://pachube.com/feeds/36745 (“Open” data, available as XML, JSON, CSV feed)
• http://www.tamberg.org/makeopendata/2011/googlecharts.html (Google Chart visualisation, JSONP)
• http://www.tamberg.org/makeopendata/2011/pachudial.html (PachuDial visualisation, Flash)
• http://www.tamberg.org/makeopendata/2011/jquery.html (Simple visualisation, JSONP)

• tamberg

• http://sourceforge.net/projects/itextsharp/files/ ( PDF to text C# library)
• http://www.paravan.ch/geocaching/#tools (CH-1903 to WGS-84 coordinate converter)
• http://code.google.com/apis/chart/ (Image and Javascript API for visualisation)
• http://en.wikipedia.org/wiki/JSONP (Cross site scriptable JSON API convention)
• https://pachube.com/ (Sensor data platform based on open standards)
• http://yaler.org/ (Access to LED Web service running on Arduino)