Rriccibitti have sent us his latest work on reverse engineering of simple keypad circuit. The solution seems to be very simple but effective. What he used is a digital camera to take a picture of the printed circuit board and a photo editing software where he could track PCB traces with different colors. OK, for this one he used Photoshop as it seems to have lots of valuable tools that make this work much easier. To be more specific let us see what he’s done: Took the same size pictures of both PCB sides with a digital camera; Put both pictures in different layers in picture editing software. Of course one has to be mirrored. Transparentized top side of PCB so the bottom connections and tracks could be seen; With the magic wand tool, he removed the color of the free top area. After this simple preparation, he simply took a bucket fill tool and market different tracks with different colors. After all, this is a really great method of analyzing unknown PCB especially if you need to repair some electronic device or even hack it.