Hi Nikolay,

OK so you want a project for your final year. For a moment forget the project, and analyse your approach - a simple truthful request ( more like the current one ) would have saved you two weeks of time.

Anyway by now you must have figured out the boundary conditions for your project "Tachometer" :

1. What is range of RPM that you want to read ?
2. What resolution for internal processing and what resolution for display ?
3. What is the sensor type going to be ? Contact, non-contact ?
4. What display will you use ? LCD , LED ?
5. Is it going to be portable or can be powered by mains ? Or charged by mains, used as portable ?
6. What is your budget to build the tachometer ?

Answer all the 6 questions above and sure I will guide you to start. And many others on this forum will also be willing to help you out.

And last, to tell you my opinion, this Tachometer stuff is one of the most done projects in colleges. Just be sure it will fetch you the right grades. So be prepared to extend the scope of the unit beyond the normal display of rpm to bring in some novelty to it.

Raghu