User Manual

135
Lesson 29 IR Obstacle Avoidance Module
Introduction
An IR obstacle avoidance module (as shown below) uses infrared reflection principle to
detect obstacles. When there is no object ahead, infrared-receiver cannot receive signals;
when there is an object ahead, it will block and reflect infrared light, then infrared-receiver
can receive signals.
Components
- 1 * Raspberry Pi
- 1 * Breadboard
- 4 * Jumper wires (Male to Male, 2 red and 2 black)
- 1 * Network cable (or USB wireless network adapter)
- 1 * IR Obstacle module
- 1 * 3-Pin anti-reverse cable
Experimental Principle
An obstacle avoidance sensor mainly consists of an infrared-transmitter, an infrared-receiver
and a potentiometer. According to the reflecting feature of an object, if there is no obstacle,
emitted infrared ray will weaken with the propagation distance and finally disappear. If there
is an obstacle, when infrared ray encounters an obstacle, it will be reflected back to the
infrared-receiver. Then the infrared-receiver detects this signal and confirms an obstacle
exists ahead.
Note: The detection distance of the infrared sensor is adjustable - you may adjust it by the
potentiometer.