PICAXE

PICAXE is a brand of micro-controller, running inside PIC micro-controllers from Microchip. These chips come in many flavors and sizes, from 8 pins to 40. They are very cheap and come with free software for programming in BASIC (MAC, LINUX, Windows) or with flow charts (Windows).

I have used PICAXE to make data-loggers, for light, temperature, and wind speed. I have also made a MIDI controller, where the PICAXE interprets potentiometer metrics into MIDI controller signals; this is useful for running TRAKTOR, see MIDI and DJ mixers.

The main web site for PICAXE is here: http://www.rev-ed.co.uk/picaxe/

Programming

The PICAXE is programmed via serial communications from a computer. Note that zero volts is logic 1 and five volts logic 0, so the serial interface will need to be adjusted accordingly. Computer serial ports -9V logic 1 and +9V logic 0. See http://forum.sparkfun.com/viewtopic.php?f=14&t=9560 for a discussion of this problem, a solution being to program an FTDI chip to use the correct logic levels.