Hmmm
Hi,
I hope you have downloaded the pdf datasheet for the 16F882. There you can see that this PIC belongs to a family of PICs starting with the 882 and ending with the 887. There is a table showing the memory size and partnumber/number of pins for these pics.
INT0 is the only external interupt source for the 882-887 family and the rest of PORTB has interupt on change support. This means that you can set up the INT0 pin to generate an interupt when this pin goes either high or low (set in SW).
The rest of PORTB has interupt on change mening it will generate an interupt if any of these pins (that has this function activated) changes state. And then you have to figure out which pin did what and why...
There is a big table for this too under CPU special features.... interupts :-)
The microchip webpage has the price for the 882 at USD 1.20 and the 887 USD 1.84. This can be the best spent 64 cents in your entire life :-). Or you can choose a 884 (still basically the same chip for USD 1.64) since this is a 40-pin package and then keeping the options for plugging in a 18F when you run out of speed and program memory)
Probably you have forgotten a few pins in your idea that you will "remember" later and making a design using a 28-pin device and planning to use more or less all pins is hmmmmm not that smart :-) (unless you really know what you are doing like Melanie and her friends).
Maybe a LCD... some more buttons..... smoke detection..... automatic fire extinguishing.... you get the idea.... things tend to grow with time and some projects newer really finish.
But if I were you I would:
Download the datasheet for the 16F882 (same datasheet as for 883 884 886 887)
Check if they are supported by PBP (if not memorize which are for later use)
Not choose a 28 pin PIC since it will kill the future plans and leave no room for misstakes
Choose a 40-pin PIC (884 or 887 if we only look at this family) unless price and pcb size is really important)
The 884 is 20 cents cheaper then the 887 but you only get half as much program memory.
Of course these prices might be different from what you pay in the stores but it will at least give us a chance to compare apples and bananas.
In the end it all comes down to what can be found in your local hardware store or what can be salvaged from previous projects.
A start is always a good start!
/me
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