requist for help

i am using ATmega32L micro controller in a simple project and i will use in simulation using proteus a connection between tachometer (package not a circuit) and ATmega32L to store tachometer reading in a next stage of the project, so i need a simple drawing or interface (if necessary) between tachometer and the micro i am using. also i need a simple circuit using bush button and led to make interrupt to micro this circuit connected to any interrupt pin of the micro controller. All these circuits will be used for simulation as i mentioned above and i need it as simple as possible cause my experience in electronics is very poor

and thanks for help