QUESTION 1: A burglar alarm system uses pressure sensors and acoustic (sound) sensors to detect the presence of an intruder. A microprocessor is used to monitor and control the whole system. A keypad is used to key in a 4-digit PIN that either activates or deactivates the system.

If an intruder is detected, an alarm is sounded and also a blue flashing light outside the building.

Descrive in detail how the sensors and microprocessor interact to detect and warn of an intruder.

QUESTION 2:

Four hardware items are shown below.

For each hardware item:

• name a suitable application

• state how it is used in the application

Give a different application in each case.

1. Barcode reader

2. Microphone

3. Touch screen

4. Infrared sensor