How To Communicate With An Alien Artifact or . . .

Step 4 The Microcontroller and Program.

In praise of the PicAxe.

The PicAxe was initially developed for the educational market in UK schools but is being widely used by hobbyists. The PicAxe chip is based on various PICs but with bootstrap code to link to the compiled programs and handle the programming side. They come in all flavours from this suprisingly powerful 8 pin package up to full blown 40 pin.
Look at the manuals and datasheets on the PicAxe site to see the full capabilities. Programming of the chip is via a serial link and done in-circuit. It takes about 20 seconds and you don't even have to unplug the lead to run the program.
I've been in electronics since the early eighties and I've never found a programming environment where the coding / simulation / proving cycle is so simple. Documentation and support from the forum is excellent and there are many robotics enthusiasts using the chips. Control for servos, steppers, ADCs etc are built in to the BASIC-like programming language as well as a host of other goodies. You can also simulate the circuit before you build, and do real-time debugging on a running controller.

Below is the code for this project, which I've included as a Word document as well as the native PicAxe Programming Editor format. The code operation is pretty well commented but if you want to examine it in more detail, download the PicAxe software reference manual.

Load the .BAS file into the Programming Editor, connect the serial cable to the programming pins and hit 'Program'. 20 seconds later, your Alien Intruder will be sitting there waiting to communicate with you.