Initial Concepts (Sensors)

In order for the buggy to follow the line it must use sensors. There are many different types of sensors available although not all of them will be useful (such as a thermistor)

More useful types of sensors are Infrared LED's with detectors, LDRs and Reed switches. Each type of sensor has its own advantages and disadvantages.

IR LED with Receivers



The advantage of using an LED with an infrared sensor is that the sensor is very precise and is not likely to get confused. The disadvantage is that the sensors have to be in the right place and have to be programmed properly.

LDR



LDRs are resistors that change their resistance by reacting to light, they are cheap and easy to use however they can be confused by outside sources of light hitting the black tape and making the sensor think that it is white.

Reed Switches



Reed switches are small switches that are switched on in the presence of a magnetic field. They are easy to use as an input because they will give a logic 1 or 0. Unfortunately it relies on the magnetic field of the black tape being strong enough to work the switch. Also the switches are very delicate so great care would have to be taken when using the line following buggy.