Mech

One topic is already a problem, and you want 4.

What parts of the mini are you working on?

http://en.wikipedia.org/wiki/Mini

Seriously, this is such a common (broad, unprofessional and lazily-asked) question (see the numerous threads on CR4).

If you expect a real answer you are going to need to provide much, much more information and actually come up with some ideas and interest yourself (as well as indicating what the project is for). At the moment it is impossible to answer without guessing (which I am not going to do).

Please provide more information.