05 - What is a Program?

A program is a list of instructions to be performed by the PICAXE microcontroller to solve a problem. Thee actions are normally required:

  1. The first is to translate available information out of the real world into the world of electronics and micro-controllers. Examples are to test if a door is open or closed, or to convert a temperature to an electronic signal and then into digital information.
  2. The second action is to use this information by reading and manipulating it in the microcontroller to make decisions, do calculations or lookup information.
  3. The third action is the translation to convert the resultant digital output information back into the desired effect on the outside world, e.g. sounding of an alarm, or the ON and OFF switching of a light or a heater.


The instructions for a microcontroller is just a set of bytes where an instruction can be one or more bytes that is executed by the controller in sequence. It is very difficult for us humans to write programs in bytes so we have developed a programming language that we can understand without having to encode byte instructions. The most basic programming language developed was Assembler. Programming in Assembler is a lot better than encoding byte instructions but it is still very time consuming and difficult to read. So we developed other higher level programming languages like C and Basic. Using these languages we can develop complex programs very quickly with very little effort.   

Microcontrollers still understand only byte instructions so we need to translate our C or Basic program into byte instructions. This task is normally done by a compiler. We then have to upload the byte information (program) to the microcontroller and this function is normally performed by a programmer.

If we use PICAXE we don’t need to buy a compiler or programmer, everything is handled by the PICAXE Programming Editor.

Writing programs for the PICAXE microcontrollers is done in a simple basic program format which makes it ideal for educational purposes as well as hobbyists.