Blum 07 - Stopping a Motor with an Optical Encoder

For this lecture project, a DC motor was equipped with a laser-cut encoder wheel. The motor is driven by a 9V battery, which is switched via a darlington transistor by the arduino microcontroller. The encoder wheel is placed between an infrared emitter, and a photo-sensitive transistor. As the wheel spins in front of the receiver, the number of spokes that pass in front of it can be counted. Since we know the number of spokes, the motor can be instructed to stop once all 60 spokes have been counted. This results in the motor doing exactly one rotation. The motor does, however, overshoot slightly, as it takes time for it to decelerate after losing power.

Category:

Science & Technology

Tags:

• info4320
• arduino
• motor
• optical
• encoder
• transistor
• LED