Just finished a trakball hack and thought I would share

[MrArcade]

I just hacked a new happs trakball to a mouse.  The mouse is a micro-innovations that I picked up at Big Lots for cheap.  The "light choppers" seemed about right...the bars and slots are near the same width....like the choppers on the tball.

The mouse is ps2.

All I did was remove the detectors (wider black things with 3 pins that are on one side of the light chopper).  I left the emitters in.  I also removed the left and right mouse button micros.

I have some thin single conductor wire for phone....6 strands in a sheath.  Once the other components were removed I just bared a tiny bit of wire and shoved it through the hole from the component side and soldered them in.  For the delectors on this mouse the outside pins are what get hooked to the trackball detectors.  Usually one of the 3 pins from the detector will connect via a trace to the emitter on that axis.  That is the pin that we ignore for now.

So, I have soldered 4 wires, 2 to each place I removed a detector.
Here is a pic  (my camera has no macro setting so it is blurry)



Now I just use a pinout diagram to find the +5v and gnd wires coming in from the ps2 connector...here is a nice page with pinouts
http://www.networktechinc.com/technote.html

Once I found the wires, I followed the traces looking for an easy place to solder to.  The +5v trace ended up going to the center pin of the removed detector on the Y-Axis.  I just bared a tiny bit and soldered it in.  The GND trace did not go directly to an open hole....but it did go directly to one side of a resistor.  So, I just soldered the wire to the leg of the resistor...on the side nearest the GND pin.  You need to get the +5v and GND before they go through any components or there will not be enough juice to power the emitters in the tball.  The star in the pic is where I soldered to the leg of the resistor.  To finish I just soldered 2 wires to each mouse button...making sure to use the 2 pins that go somewhere...the third pin had no trace going anywhere.

To wire it to the tball I just cut off the plug at the end of the tball harness.  The inner 2 wires on each axis are the +5v and GND, the outer 2 are the detector wires.  Most tballs have the same color wire going the each axis for +5v and the same color for GND.

I just twisted the 2 +5v together and soldered them to the +5v from the mouse and twisted the 2 GND wires together and soldered them to the GND from the mouse.  The axis wires I just twist together for now.  Two from the mouse X-Axis to the 2 tball X-Axis and likewise for the Y-Axis.  

Then test the tball.  Before I plug it in I test for shorts.  When soldering a point that is very near another it is easy to get some solder across the gap.  I just do a continuity test between the points near others.  If you have no problems plug it in!

If the cursor moves the wrong way you just need to swap the 2 wires on that axis.  If it does not move at all it is possible that you have the +5v and GND reversed.  Once it is all working correctly just solder the wires and insulate all the solder points.

Now all I have to do is mount it and hook the mouse button wires to the buttons on the cp and it is all done!

I hope this helps some folks!

[MrArcade]

Here is a pic of the mouse:

[Xiaou2]

Any ideas on hacking a USB mouse?  I got a CompUSA usb mouse... and it has four soldier points on each optic...?!

 tia  : )

[MrArcade]

is this optic a "U" shaped deal that the light chopper sits in?  Most mice have 2 seperate components for each axis...an emitter and a detector.  Some mice have both combined into one little unit.  This would have 4 solder points...

[SirPoonga]

Any ideas on hacking a USB mouse?  I got a CompUSA usb mouse... and it has four soldier points on each optic...?!

 tia  : )

Which model?  CompUSa has a few of it's own?  Is it the scroll wheel one with the ps/2 adaptor?  That;s what I hacked.  Give me an email, I'll take pics and send you what I did.

Note, I powered my trackball optics with a second USB cord because I orifignally had a ps/2 hack.  I figured I wouldn't unsolder parts.  Plus it makes it more reliable I think.

[rampy]

Nice little write up MrArcade...

That'll come in handy when I get a trackball... someday...

rampy