Mouse/trackball click on a keyboard

Since several year, I started to feel some pain in my left arm and left shoulder, that's the side of my mouse. So I decided to do something , first I moved the mouse of the right side (I am left handy) , using the right arm instead of the left. But still , it was not enough, so I switched to a trackball. Trackball is much better as it avoid to move the whole arm, so only finger can operate. But the click buttons (left and right) are even more difficult to manipulate without moving the ball.

So, I installed a small application on my PC (neatmouse) , to simulate mouse click using some keyboard keys. First, i configured F1/F2/F3 as left/middle/right button. So far it worked ok.
But for some application it does not work correctly, for instance when using Virtualbox and linux guest. Linux can't be configured good enough so that it behave same as PC when hitting those remapped keyboard keys.

Then I decided to build a mini keyboard to replace those F1/F2/F3 + configuration to make a solution fully portable on any PC.
This is my first prototype of  a mini-keyboard for mouse click. Left/right button behave exactly as left/right mouse or trackball click.  This is much better, now I can use this mini keyboard as a full replacement of my mouse/trackball click button.

The mini keyboard is connected directly inside the trackball, on the left and right switches. It  easy to install but requires some basic soldering. There is no need for any software or configuration in windows/linux, or any change on the PC itself.

A more designed version, with nices buttons  is planned soon  :)