With a wealth of old computers around, the resourceful robot builder can find most everything needed to make a simple, yet highly controlable robot, for practically free. We will see how this is done and how the robots are controlled with a simple program you can write.
The robots featured on these pages use uni-polar stepper motors salvaged from old 5-1/4 inch disk drives. The also use a ULN2003 darlington array integrated circuit, also salvaged from the drive or available for less than 40 cents at various vendors. The motor is connected, via a cable, to the parallel (printer) port of a DOS/Windows computer. A 12-volt power supply is provided to the ULN2003 chip from the computer or an external power supply. The motor is controlled through software written in QuickBasic.
When I launched this page in 2002 I also made a presentation at the Montana Education Association Conference. The slide show I used in conjunction with the presentation is available below.
|Slide Show From the Presentation|
|Slide Show - HTML||Click on the link to the left to view the slide show presentation as web pages.|
|Slide Show - PDF||Click on the link to the left to view the slide show presentation as a PDF file.|
|How-To Build the Robot|
|The Trainer||The Trainer is a simple device that can be used to learn how to program the computer's parallel port. It consists of 8 Light Emitting Diodes and 5 push-button switches and a cable that connects to the parallel port.|
"How To" Page
|This link will walk you through the bare essentials of getting a single stepper motor to turn using the parallel port of the computer.|
|Schematics||Click or right-click on the links below to access the wiring diagrams in various formats.
|The Software||Click on the link to the left to go to the page with sample programs in QBasic.
00-inp.bas - Test parallel port input.
|Related Web Sites|
|Interfacing to the PC Parallel Port||This site has extensive information about interfacing to the PC's parallel port. There is also detailed information about the use of stepper motors.|
|Mouser Electronics||This is a well-stock electronic parts supplier.|
|Radio Shack||Not as complete as they used to be but they have many useful parts and there are stores just about anywhere.|
|Robot Builders Bonanza||A great book by Gordon McComb. McGraw-Hill/TAB Electronics. ISBN: 0071362967. 2nd edition (September 21, 2000). Clicking on the link to the left will take you Amazon.com.|
Copyright © 2002, Vince Long