Hello!
A few of us here at Pololu have put together a library to make it easier for Arduinos and Orangutans to interface with Pololu QTR reflectance sensors. The library defines classes that can be used for either the QTR-xA or QTR-xRC versions, and each class supports up to 8 sensors (be they individual, in an array, or a combination of the two). You can create multiple instances of the class if you want to use more sensors. The library provides some advanced features such as calibration, reading the sensors with the emitters on and off for greater immunity to uneven ambient lighting, and a routine designed specifically for line following/detection that will tell you where it thinks the line is relative to your sensors. You can find documentation for this library here:
For an example of what you can do with QTR reflectance sensors, this library, and a little code, please see my maze-solver video in the exhibition forum.
- Ben