I am searching for a DIY set to build an optical mouse. What I need is a bare minimum set, giving the ability to build a very small mouse without buttons, and possibly for beginners. Should be something that can be plugged in the computer and can be practically used with Windows at least as a pointing device. If the device cannot fully and automagically comply as real mouse it could be also a possible solution for my project, if there is a dev-guide to get something from the moving sensor.
So I want to build a 'pointing-only' mouse. The button components should be included, but must be splittable from the sensor and light element, so the wires could be laid separately and all buttons distanced from the mouse, e.g. under the left hand.
My idea is that I build the body of the mouse myself, and the sensor stuff I will mount according to my needs. For this reason, the strict criteria is the form-factor of the main movement capture component, namely it should be the smallest possible. This block for the gliding body should be splittable from the rest as much as possible, and connected with thin flexible wires.
So a common monoblock with buttons or wireless solutions are out. Mechanical wheel solutions are also out.
My first idea was simply to destroy some very small mouse and look what is inside, but I really hope there is a more civilized solution.
I ask for recommendations about possible electronical components and general advice for such project. Note that I am not electronics engineer, I am working on mechanical concepts mainly and have some programming skills, if thet can help.