First answer me this. Where are you going to get a sensor chip? You can't do it with out one. Then you have to design and build the circuitry to take the info off the chip matrix and code it into something use able that the computer can use. Then you have to write the software to get the data on the screen. You would be better off using your time to earn the money to buy the camera. Then earn some more and buy a really nice electronics set so you can learn all the stuff you need to know so you can see how really difficult this project really is. P.S. Your question took nearly two days to show up because your title was less than 5 words long. I found out that if the question is less than 5 words long it has to be looked at by a human and you never know when they are going to get around to it. Good luck.