This Wireless IV Curve Tracer for long term solar photovoltaic field testing was first designed and tested by Jason Alderman here. It is for long term outdoor solar photovoltaic test facilities to measure IV curves of modules.
The hardware was designed and built as a personal project in an attempt to address the shortcomings of a traditional IV measurement setup. The hardware and software are open source. Jason's IV tracer has just two wires to connect to the panel under test. Other than that, it's completely self-contained and portable. When the panel isn't being measured, the logic circuitry is put to sleep and the panel's power is instead used to charge a small lithium ion battery. Even in complete darkness, the IV tracer can run from the battery for a couple of weeks, and as soon as the sun comes out, the battery is quickly recharged.
The IV data is transmitted as ASCII text using an Xbee in transparent serial mode. On the receiving end, a simple USB-Serial adapter is connected to a Linux PC and a very basic logging script.
The complete IV tracer cost me about $140 to build, which is a huge cost savings in addition to the time saved from not having to mess with miles of wiring if you are doing a complex site like the OSOTF.
Full details: [1]
