DIY

CIRCUITS

THE POWERFAKE

Make an inexpensive desktop scroll wheel and volume control. By Daniel Walker

The Griffin PowerMate (griffintechnology.com/ products/powermate) is an assignable USB knob controller that you can set up for many purposes, such as browsing Google Earth, scrolling web pages, controlling volume, and so on.

Photography by Ed Troxell

I took a look at some You Tube videos of it in use and thought it was literally a scroll mouse on its side with a fancy knob and some software. A few Googles later, and I found a post on the bit-tech.net forums about a guy who made his own from a VCR spindle and an old mouse. I fancied a bit of that, so away

I went, and this is what I came up with.

I call it the PowerFake. It’s made from an old PS/2 mouse, a project box, and an old R/C car wheel. The basic idea is to liberate the mouse’s scroll wheel encoder from its circuit board, reconnect it using wires, and set it up to run off of the knob of your choice.

MATERIALS

PS/2 or USB mouse with scroll wheel You need a rotary encoder for the scroll wheel, not an IR transmitter/detector. A ball mouse is more likely to use a rotary encoder than an optical one.

R/C car wheel and tire or other circular object you can use for rotating that fits in your hand easily

Project box

Thin metal rod of suitable length to go through your R/C car wheel, project box side, and the rotary encoder. It could be a thin nail or a piece from a large paper clip.

Soldering iron and solder

Solder wick or desoldering pump

Tape or glue to mount the encoder. I used double-sided foam tape.

Super glue

Drill

Screwdriver

Small piece of stripboard, aka perfboard (optional)

Make: 165