The Parallax Basic Stamp 2
Like many people, I'd seen the adverts for the Basic Stamp and Basic Stamp II for a few years and hadn't really given them too much thought. Nice idea. After all, there isn't much around for hobbiest or educational electronics. At a secondary (or High school) level, there's a big gap between getting a transistor to turn on a LED and writing macros on a PC. Something that is reasonably easy to use and actually does something has to be good for encouraging students into the industry.
Anyway, I had a requirement for a simple, one-of solution and thought I'd give one a try. The client was quite keen to be able to have a fiddle after I'd got the initial system up and going so it seemed to suit the task well.
The starter kit comes with a Basic Stamp II, a carrier board, some PC software, a serial cable and a 25mm thick manual. The BS2 is a 24 pin DIP footprint and includes a voltage regulator, oscillator, reset generator and simple transistor RS232 interface. It's all there.
The PC software is a fairly rudimentry DOS editor with a mapping function to show the resources used and as the source code is a standard text file, you can write in your favorite editor if you prefer.
The carrier board gives you a socket to plug the BS2 into, a row of pin headers to get at the pins and a breadboard area. It also has a DB9, a reset button and the connectors to accept a 9V battery.
The manual reflects the fact that the product is aimed at the hobbiest market. There are quite a few application notes and everything is explained well, assuming that the reader hasn't used a controller before. There are a host of useful, built in functions such as PWM, Frequency outputs, pulses, pause, DTMF, simple serial output and so on. Even SIN,COS & SQR.
The function blocks are quite fast (pulse resolution is 2us) but the interpreter itself isn't. A simple loop, reading 2 pins and outputting the value to two others took between 100us and 800us to execute. There are no interrupts and no concurrent actions, so if you start a PWM, you don't do anything else until it's finished. It's certainly no computing monster but that's not its intention.
What I particularly like about it is that it is self contained and functional. Plug in a battery, slap a quick bit of code together and squirt it out the serial port and it's done. It doesn't need to be connected to anything to run. Compare that to hunting around for a breadboard and all the bits to use a 555 or hooking up to the bench supply and the signal generator just to generate a repetitive reset pulse for your real project. For all those annoying little things, this is a really handy solution to have sitting in the top drawer.
It's now 18 months later and I have found the Stamp gets used more often than a lot of the other test equipment I have collected over that time. For people starting out in the area of microcontrollers, I can't recommend it highly enough. It's one of the few things that is a good teaching tool and remains useful once you are an old hand at the art.