The reflectance sensor is one of the most important components of the AEV. It searches for the reflective tape on the AEV’s wheel, and keeps track of every time the tape shifts from being present to non-present. Each time such a change occurs the reflectance sensor records a single mark. Since there are two pieces of tape on opposite sides of the wheel, eight marks are recorded per revolution, as the reflective tape shifts from being present to non-present eight times.
Each mark is equivalent to 1/8 of an inch. When writing code for the AEV, however, marks must be the unit of distance used. Thus, in order to effectively write code, inches need to be converted to marks, and vice versa.
A picture of the reflectance sensor properly attached to the AEV arm is shown below.
A picture of the reflectance sensor wires properly attached to the controller board is shown below as well.
