Queston on mouse hack with 4 pin receiver...

[gndprx]

Okay, all of the tutorials around only describe 3 pin receivers for the pickups.  I have a bunch of old compaq and dell mice that have a very small footprint logitech board in them (1 1/2" x 1 3/4" maybe).  However all of them have 4 pin receivers.

Any ideas on what the 4th pin may be?

[zero-one]

Hi.

Sorry I can't help but I feel your pain. Most of the mice I've accumated over the past 10 years were of the logitech variety and have 4 pins per receiver. I didn't even try hacking them. Only a very old IBM mouse was suitable to hack. I was not about to go buy another mouse.

All I can say is that Logitech must have made more mice than any other company. They're everywhere!  

[SirPoonga]

I hacked a 4 pin compusa mouse.
Here's a pic, I will explain as best I can.

http://www.fe.donkeyfly.com/images/mouse1.jpg

First off it is a cheap mouse!  Noticed I tried soldering to where the IR receivers where.  The top layer of the electronics came off.  So I followed the circuits back tot he chip and soldered to the chip.

A red and green wire represent a pair that go to the trackball.  The ground on the reciever is faily obvious so oyu don't need to worry about that.  What I did then was make leads with quick disconnects to each of 3 pins from both receivers (actually leads came from the controller chip where the receiver circuits went to).  Then it was trial and error.  Make sure you unplug the mouse before you change wires around.

5v and ground I got form the USB's 5v and ground on the mouse.