Advantages
Picaxe microcontrollers are perhaps the easiest controllers to program and use. They are basically a universal circuit that can be programmed to emulate almost any circuit. You can program them to be a timer, a voltmeter, a blinky, an alphanumeric display, a music player, an infrared transmitter, an infrared receiver, a frequency generator, a rainbow readout, a sound effects generator, an x10 controller, or a master robot controller.
They are actually Picmicro microcontrollers that have a bootstrap program installed that make them easy to program with your PC in Basic--an easy to use programming language. It is almost identical to Pbasic which is used to program the Basic Stamp2. They hook to the PC with a serial cable or an optional USB to Serial cable.
The 28pin Picaxe can essentially replace the Basic Stamp2 and it is considerably less expensive. You can buy three 28 pin Picaxes for less than the price of one Basic Stamp2. One other advantage over the Basic Stamp is that Picaxes have built in A/D converters. These analogue to digital converters allow them to measure a voltage at an input pin and convert it to a number in the program. This makes it easy to interface all kinds of analogue sensors.
Disadvantages
Because they are preprogrammed to accept a Basic program download, a Picaxe chip runs programs considerably slower than a Picmicro programmed in C. For most projects, this is not a problem. For projects where you are multiplexing a large number of LED's, this slowness can introduce a flicker to the final display. In programs involving long calculations they can introduce a noticeable time delay between input and outputs.
Getting Started
If you want to program your own chips, the best source I have found for Picaxe chips, download cable, and programming software is HVW Technologies. The programming software comes with a good tutorial that will teach you Basic programming and Picaxe interfacing.
If you want to see some schematics of the Picaxe projects I have done, check out the Picaxe Projects Page.
Copyright 2007, Inkless Press