Control freaks alert! : a clean interface to Beehive Technologies' ADB I/O using object-oriented Lingo

Abstract

The ADB I/O by Beehive Technologies is a device which you can connect to a Macintosh to communicate with external electronics. Simply put, the ADB I/O provides digital inputs (to read switches), digital outputs (to switch things on or off) and analog inputs with 8-bit resolution (to read all kinds of sensors). For the Macintosh platform, it has opened up areas of application to mainstream users that were previously the sole territory of electronic hobbyists or users with high end data acquisition hardware. A few of those areas are home automation, robotics, kiosks, scientific experiments and product simulation. Many applications can communicate with the ADB I/O. One particularly powerful combination is the ADB I/O and Macromedia Director. Even if you intend to control your ADB I/O through AppleEvents or C/C++, you may find it worthwhile to test your set-up with Director. Director is easy to program, especially when it comes to the graphical user interface. There is of course a downside to Director's ease of use: the temptation of sloppy programming. Director does not require you to declare local variables or provide function prototypes. Add Director's cryptic error messages and your program can turn into a tangled mess which is difficult to debug. While this is of course undesirable for any program, with a program that communicates with external devices, for example motors, the consequences of messy programming may be more severe. This article aims to help you in battling messy Director code. By using Director's object-oriented features you will get to build a friendly and clean interface to the ADB I/O. In addition, in this article consistent naming for variables is used, which may be of help to you in writing your own scripts