CASE STUDY
1) How many different things did you count? What were they? In what ways might computers be used to control different things in the supermarket?
Four things. They were the security sensor, key card, elevator and the CCTV. The computer system will sense this stuff.
2) Why is it useful to use computers rather than people to control things? What problems might there be if any of the computer systems fail in the supermarket?
Humans need rests but computers can work for the whole day automatically. Problems could be that there are wrong temperatures in the freezers and food has the wrong temperature too.
3) Describe the inputs and outputs for the other devices that we have talked about so far. How do the supermarket doors and car park barriers know when to open? Identify other control systems that work automatically in this way.
The supermarket doors will know to open when it senses a person or obstacle in front of it. A car park barrier knows to open when someone pushes the button or when a car comes close to it. Car systems that sense when cars park or GPS systems work the same way.
4) What would happen if the instructions were wrong? These instructions assume that the car is in the right place? How could they stop this happening?
They could put a loop in the instructions so that if there is not a car, the system senses it and stops.
