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geekhack Community => Keyboards => Topic started by: aknagi on Thu, 16 December 2010, 13:16:57

Title: Shoddy MX11800 Trackballs + Micro Controllers = Scrolly Balls
Post by: aknagi on Thu, 16 December 2010, 13:16:57

When I got three MX-11800s in the post and the trackballs didn't work on any of them, I theorised that I had a firmware / compatibility issue. Some have hinted that these keyboards have this kind of problem, and others have pointed to low quality hardware being the problem. It turns out that the former group were right.

I decided to make a PS2 to USB adapter from an AVR ATmega8 micro-controller in order to make the trackball be a "scroll ball" during text editing and surfing that could turn back into a trackball for playing Marble Madness. It's working, but it's still on the breadboard.

(http://geekhack.org/attachment.php?attachmentid=14086&stc=1&d=1292526743")

Source and schematics are here https://github.com/nagi/trackball2scrollball. Possible modifications could include:

• Make a scroll ball / track ball out of an upside down P2/2 mouse.
•  Add extra buttons to / generate programmable key sequences from / swap scancodes around on a Model M.
•  Make a jog wheel for AV editing etc from an old PS/2 mouse.
•  Log key presses and display your "words per minute" on a 7-Segment Display or a rev counter from an old car.
•  For a non-clicky but tactile keyboard, add an audible click when a switch is activated (good because you can add a mute button and take it to work).
•  Add the flash of a lamp in your peripheral vision to give enhanced visual feedback when the switch activates.
•  Make a novel game controller to keep fit (I'm working on that next).
•  Port to Arduino.

I still have a couple of issues with my keyboard though: the scroll lock key and number pad work well in Windows but not in Linux. It is plugged directly into the PS/2 port. Can anyone help point me in the direction of a fix?

Cheers,
Andrew

PS - To those who found this searching for a fix to MX-11800 trackball issues, note that a poster on ubuntu forums notes that the trackball works in Xubuntu 7.10 but not Win98 or Damn Small Linux 4 http://ubuntuforums.org/showthread.php?t=763228. This means you may not have to build or buy an adapter to fix your problem if you have an otherwise working mouse PS/2 port.

Title: Shoddy MX11800 Trackballs + Micro Controllers = Scrolly Balls
Post by: PRISONER 24601 on Thu, 16 December 2010, 14:50:48

That is SUCH A COOL idea. Seriously. Props.

I've been lucky with my MX11800s. The (logitech made) trackballs work with all my USB adapters so far.

Title: Shoddy MX11800 Trackballs + Micro Controllers = Scrolly Balls
Post by: aknagi on Thu, 16 December 2010, 15:24:38

Thanks Prisoner.

Do you know the makes / models of the adapters you have got working, as I may buy one to attempt to fix my scroll light / number pad in Linux?