Microcontrollers

Take me to the 'Year 8 Microcontrollers' page.

What are Microcontrollers?

Microcontrollers are electronic components used to control the behaviour of systems according to a predefined set of instructions. Essentially they can be used to switch on and switch off a range of electronic output devices. They are very useful when unique behaviours are needed which depend upon different circumstances, e.g. at a pedestrian crossing where it is normally important to keep cars moving to avoid traffic jams (so it is desirable to only turn the traffic lights red when a pedestrian wants to cross the road).

Microcontrollers contain tiny 'integrated circuits' or IC's which are packed with thousands or even millions of transistors. A transistor is an electrical switch. By combining lots of switches together we can create 'logic gates which help store digital data and make calculations extremely quickly. These ones and zeroes (or on's and off's) are used to create simulated 'truth tables'. The final result of a truth table determines whether the output is turned off or on.

You might say that microcontrollers can be programmed to make 'intelligent' decisions. They do this efficiently and more quickly than a human can, however they require programming to work properly.

An advantage of microcontrollers is that they can be used to control more than one circuit making them cost effective in large systems and they can be programmed with complex behaviours which change depending upon their environment and their operating conditions. This is why microcontroller circuits are usually packed with sensors which provide the inputs for their internal decision making. If it is possible to shrink the size of a circuit then it is possible to make products 'smarter', smaller and lighter.

Earlier microcontrollers were not able to be reprogrammed, however more modern ones contain flash memory chips and can be 're-flashed' with new programming if necessary. This helps enable updates and bug-fixes and can be used to maintain security. This is important to avoid data being stolen or changed without permission for criminal purposes.

The disadvantages of microcontrollers is that they are more expensive than using traditional 'discreet' (seperate) electronic components and soldering them together (however this would take up more space and be more complicated to get working), and they require specialist knowledge to program in the first place.