M
O
WAY
Title
: mOway Beginner Manual
Rev
: v2.1.3 – March 2011
Page
11
of
65
www.moway-robot.com
•
Accelerometer.
•
Battery level.
Image 4. Sensors and indicators group
3.3.1.
Line sensors
The line tracking sensors are two reflection optocouplers mounted on the top front
part of the robot. They use infrared light reflection to detect the color of the terrain at
the point where the robot is.
These two sensors are connected to two microcontroller analog ports so strong
terrain contrasts, like white lines on black backgrounds, can be detected. They are also
capable of distinguishing different tones.
The Vishay CNY70 sensor has a compact construction where the emitting light
source and the detector are arranged in the same direction to be able to detect by using
the reflective IR beam the light reflected in the terrain.
In the images below the three possible cases can be observed:
1.
Clear surface
: A white surface reflects all the infrared light and
therefore we obtain a low voltage reading at the transistor’s output when
in regular mode.