- on Microcontrollers
- Published in issue 2/2000 on page 0
PC keyboard encoding
Everything you ever wanted to know about the signals from a PC keyboard…
…and couldn’t find anywhere, you will find in this Elektor article (and where else would you find it?). It’s a natural idea to use a PC keyboard for developing microcomputer applications, for example, in order to send commands or respond to specific actions. Why go to the trouble of building your own keyboard when you can use a ready-made (and inexpensive) PC keyboard? The only problem is that you first have to know exactly what signals a PC keyboard supplies.In addition to the ready availability, low cost and accustomed manner of use of a PC keyboard, connecting a PC keyboard directly to a microcontroller system has the advantage that it makes valuable port pins available that otherwise would be used for polling a keyboard built from individual components. A PC keyboard, by contrast, produces a serial signal, and is thus an ideal complement to a microcontroller project. Of course, the manner in which the signal from the PC keyboard is constructed has a few special features.