Zumo Reflectance Array

Proud photos of the reflectance array. This took a little bit of sorting our to get it working correctly. But we got there in the end. The first time that we got it to work was just amazing! We all stood round it and watched it follow a line of black masking tape around a table in the graphics room.
Here a are a few photos to explain some of it to you...

 The reflectance array consists of six sensors, each consisting of an IR emitter coupled with a phototransistor that responds based on how much emitter light is reflected back to it. The two outside sensors are positioned at the very edges of the module to maximize their usefulness as edge detectors (e.g. for seeing the white edge of a sumo ring) while the four inner sensors are closer together for better detecting lines.

The Zumo Bot chassis with the Arduino R3 mounted on top of it upside down.

The two outside sensors emitting IR. The array is mounted on the leading edge of the bot chassis, just behind the blade. This photo shows the bot positioned upright, balancing on its back.

A closer photo of the array