I guess you have checked the biggest reservoirs: the Internet.
Have you checked PIClist.com aka the biggest reservoirs for PIC
outside Microchip? ;)-

The university libraries can also be a good resource. 

Then talk to a patent lawyer. Even if there are some similar prior
arts, probably they can still make black to white and vice versa.
They are talking in some foreign-to-mankind language so that 
nobody will understand them. Then you can claim as much as possible,
even blinking an LED using a PIC pin with some special features. ;-)

Regards,
Xiaofan

-----Original Message-----
From: Wouter van Ooijen 
Sent: Thursday, September 22, 2005 5:11 AM


Now for something completely different: I think I have a realy original
idea (about reading a matrix keyboard with very few pins). I have
browsed a patent database and found some 20 patents in roughly the same
area, but nothing like my idea. What would be the next step to prove to
myself that it has been cooked up before, in other words: which other
reservoirs of knowledge should I check?

Wouter van Ooijen

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