BUILD A USB VOLUME
AND MUTE CONTROLLER
FOR YOUR PC
By Richard Dzioba
Discuss this article
in the Nuts & Volts
forums at http://forum.
■ FIGURE 1.
This project started out from a need to add externally adjustable volume and
mute capability to my laptop computer. I listen to a lot of music and found
that the existing touch-sensitive volume slider control on my laptop did not
make it easy to do fine volume control adjustments. Plus, if I wanted to listen
to music with the laptop lid closed, the volume controls were inaccessible and
there was no way to hit the mute button. I needed an external control that
was compact, powered from the USB port, and would not require any special
drivers to be installed.
You are probably thinking “why not just get an MP3
player and your problems are solved?” Yes, that’s true.
However, but if you are an avid electronics hobbyist, you
know that isn’t how it’s done. Simple solutions are not as
much fun as a project! Here was a good opportunity to
learn about USB and end up with something of practical
use. See my solution in Figure 1.
38 January 2012
I chose the AT90USB162 microcontroller from Atmel’s
AVR eight-bit line for this project. It has both a general-purpose microcontroller and a USB function controller in
one chip. It can be powered from the USB port, so no
additional power supply is needed. As an added bonus,