Using an optical mouse for a trackball.

[markb]

I've recently built my first Mame/Game cabinet and am now in the process of putting on additions such as light guns, external volume control, steering wheel, trackball etc in addition to the 2 joysticks I started with.

So far I have done everything on the cheap but now it's time for the trackball. I had an idea this morning that instead of hacking a standard roller mouse it may be better to use an inverted optical mouse housed in very close proximity to the bottom of the trackball.

I done some research and it seems that an optical mouse works by picking up imperfections in the surface of whatever it is run over to detect motion. After purchasing a field hockey ball for

[Bgnome]

i have heard of people attempting this, but pretty much stopped due to the 2 problems you mentioned.  the first was the ball.  if you are happy with a roughed up field hockey ball then that is fine.
as for the axis, i am unaware of a software solution.  i believe that mame will let you map mouse axes so you can try mapping that axis in reverse.  as for a hardware hacking solution, i could see how thats possible but cannot help you out in that respect either..

[daywane]

I know it called B.Y.O.A.C.
I do enjoy building them. Very much so. I ahve built my own spinner . that was fun and works great.
hacked side winder to death.
Hacked Play Station controllers.

TRACK BALL  
I have spent enough money on used track ball to make me sick. I have taken apart so many mice just to find out its the wrong type
I got 2 working but thay were so worn out I hated them.
( Man am I going to get flamed) Bite the bullet and get a new one.
I just got a new one from ebay $80.00 usb and ps2 with 3 button wires
I put up a good seller plug in the for sale section of this site.
here is one of his auctions.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=13718&item=6118355217&rd=1
I do not know him personally but I will buy from him again
I am VERY happy with mine

[patrickl]

I think you can switch axes in MAME too yes. The ball would be a bigger issue for me. I think my logitech trackball is optical and it uses a patterned ball. That looks quite OK. But then it's a PC trackball so it won''t work for games (no free rolling).

If you want to buy a trackball then maybe an Ultimarc is a cheaper option. There is a thread comparing the 2 1/4 Ultimarc trackball vs Happs They come without an USB hack though.

[brained]

I think you can use an optical mouse with a trackball, I've found out that the IC inside mice can acomplish several tasks, you can look at the technical reference from that IC and it will guide you through

[Bgnome]

obviously, if someone was going to go through the trouble of building his own trackball, he would have considered buying one at least to some degree.
personally, i would think that this ball, (acrylic juggling ball with sparkles), would work nicely and look pretty to boot when a LED shines through it:


macally has a similar optical PC trackball, so i know it works:


if you mount a ball above the optical sensor from an optical trackball, at least then you would get the correct axes.  i noticed in another thread, someone actually looked up the IC datasheet for the chip in his mouse, so maybe that be something for you to do.

[markb]

Yeah, I've given it a lot of thought about buying one but I live in the UK and they are not easy to come by without quite a lot of expense. Maybe If i don't get this little project working I will splash out.

I have had a bit more success though, I found a little program called 'reverse mouse' it was on a practical joke website and runs in the background to other applications. It inverts the mouse directions and is only 15kb in size so I am going to see if I get get it to change only one direction of the mouse instead of both.

I like the look of that juggling ball, I bet that would look cool back lit. I've just tried to spray paint the nylon hockey ball with flecked metallic paint, it was a no go as the mouse would not pick it up. Still I have a few more options before i try and change the innards of the mouse.