An overview of the sensors

Before you begin, you'll need to decide which sensors to use. You require basic sensors that will return information about the distance to an object, and there are two choices—sonar and infrared. Let's look at each.

Sonar sensors

The sonar sensor uses ultrasonic sound to calculate the distance to an object. The sensor consists of a transmitter and receiver. The transmitter creates a sound wave that travels out from the sensor, as illustrated in the following diagram:

The device sends out a sound wave 10 times a second. If an object is in the path of these waves, the waves reflect off the object. This then returns sound waves to the sensor, as shown in the following diagram:

The sensor measures the returning sound waves. It uses the time difference between when the sound wave was sent out and when it returns to measure the distance to the object.

Infrared sensors

Another type of sensor is a sensor that uses infrared (IR) signals to detect distance. An IR sensor also uses...