9. Lights

Lights such as LEDs (Light Emitting Diodes) can be connected to a computer and respond to electrical signals which tell them to switch on and off.

Control devices such as lights, buzzers and motors are used when the computer is controlling a situation such as traffic lights.

Advantages

• They can be used in a computer control simulation and help provide evidence that the simulation is working correctly
• They can provide a warning for users with hearing loss who might not be able to hear the error beeps produced by the internal speaker.
• They come in a large range of different colours

Disadvantages

• The bulb may break or wear out and need replacing
• There may be a loose connection which means the light doesn't switch on even if the circuit or control program is correct