How To Build Parallel Port Prototypes


The computer parallel port is the easiest way to control devices outside the PC, like LEDs, lights and even home appliances. In this tutorial we will teach you how to use the computer parallel port to control circuits outside your computer.

The greatest thing about printers nowadays is that they use USB connection. Thus, on the majority of modern PCs the parallel is not used, so it is available for us to use it to control circuits outside the computer box.

In fact the idea behind parallel port is really simple. It is an 8-bit parallel interface, so you have eight bits available there. Simple put, since each data bit can be set as either “0” (“turned off”) or “1” (“turned on”), we can directly turn on or off up to eight devices, like LEDs, lights and even home appliances. You can connect LEDs direclty to the parallel port and play with them – actually that is exactly what we are going to do in this tutorial, since this is the best way to learn how to use the parallel port. But for “heavier” circuits like lights and home appliances, you will need to build a power circuit, because the computer parallel port is not capable of driving enough current to deal with such devices. We’ll explain how to build this kind of circuit as well.

Building Parallel Port PrototypesFigure 1: Connecting LEDs to the parallel port.

Author: Gabriel Torres

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.

Share This Post On
Subscribe To Our Newsletter

Subscribe To Our Newsletter

Join our mailing list to receive the latest news and updates from our website.

You have been added to our newsletter!