VEX Infrared Line Tracker
The Line Tracker is an analog sensor consisting of an infrared LED and an infrared light sensor. In this project, the Line Trackers will be used to determine if a disk is detected or not. This can be done by using a threshold of values.
The Line Tracker is an analog sensor which means the infrared sensor will return a value anywhere between 0% and 100% light reflectivity.
There are two main components inside of the Line Tracker, an emitter and a receiver. The emitter dispenses infrared light and the receiver records the amount of infrared light received back once it has been emitted.
If there is no object in front of the sensor, there is nothing for the light to reflect off of and thus, no light is detected as received. This would produce a low value, anywhere from 0 - 12% depending on the amount of light in the environment. In this project, when there is no disk in front of the sensor, a low value will be reported.
If there is an object in front of the sensor, there is something for the light to reflect off of and thus, light is detected as being received. This would produce a higher value, anywhere from 12% or higher, depending on how close that object is to the sensor. In this project, when there is a disk in front of the sensor, the value will spike and a higher value will be reported.
Note: for more information about Line Trackers, view the Line Tracker article from the Knowledge Base.