PICAXES and microcontrollers

These pages present a range of resources and materials on the innovative PICAXE devices from Revolution Education and supported by Intellecta Technologies.

However, it is important to briefly run through the important concepts.

What are Microcontrollers?

Microcontrollers, or tiny versions of computers, are embedded inside many common electronic devices.

Your mobile phone, TV controller, microwave or car, has one or many of these wonderful devices that make it really easy to control the operation of the devices.

The Microcontrollers or micro’s as they are commonly called, owe their power to the fact that they can be programmed to undertake a set of instruictions or tasks.

For example, when your turn on your mobile phone, you will see things happen on the screen, sounds may occur and the system finally comes to rest waiting for your input or response.

The very powerful micro has run these tasks.

What do these microcontroller look like?

They are small electronic components usually coloured black with little pins or legs coming out of the black body - a little like a black ant

They come in different shapes, sizes and power. Some of them have a massive amount of special features whereas others are really simple and designed for simple, low cost applications.

Why are the micro’s useful?

The micro is a very useful electronics component because it can be connected to lights such as light emitting diodes, switches, sensors, motors and hundreds of other devices.

The real beauty of the micro is that it can be programmed to run a specific set of instructions or tasks such as:

Read the sensor value

Read the switch

If the switch is ON and the sensor is greater than 25 then

Sound the overtemperature alarm.

These commands are part of a program

How do you write the instructions?

The program is written on your computer in several languages such as machine language or assembler, BASIC, C, Forth and others.

These instructions are then converted into the language of the micro through a process called “compiling” and then downloaded into the microcontroller.

Alternatively, there are a number of graphical ways of writing your instructions.

The Flow chart is a good structured way of setting up your instructions.

What are the PICAXE microcontrollers?

The unique feature of the PICAXE system is that programs are downloaded via a direct cable link straight into the microcontroller, so no expensive programmers or erasers are required. The easy to use software called the Programming Editor is free, and so this low cost approach also means that students can use the whole programming system at home.

The PICAXE system has a variety of devices that range from a small 8 pin device right up to a 40 pin complex device.

The developmental software is well supported with examples and documentation that make it really easy to get to grips with the interfacing, programming and expanding the applications of the devices.