Hi PICer friends,

many thanks for a lot of suggestion about the subject. In my mind now I have
a clear idea whay can I do.

I try to explain.

The application is very similar to a mail box (for paper mail), whit the
same hole to insert mail. (2 x 6 inch).

Each time a envelope in feeded trought the hole an IR barrier intercept it
and count.

As a principle of operation, I would like use only 16F84 resource, on one
pin I modulate the LED and charging a capacitor, and on other pin i read
trought a phototrasnistro the light until the capacitor is discharged.

Do you agree??

Ciao

Leonardo