I want to start modifying some old joysticks and other devices to be usb compatible.
I have found this chip: PIC16C745 which would be the perfect start. It has 5 analog axis (works with 100kohm and 5kohm pots) and something like 17 switch inputs.
When the device is plugged in to a computer using that chip, it is automaticlaly recognized as a HID device. Perfect, just what I am looking for.
now comes the hard part, how to design a properly working board? I am looking to build something simliar to this board: http://dave.bit2000.com/aki.html but I want to be able to customize it as I see fit plus i can get reprogrammible versions of the chip for around 11 dollars and OTP verisons for around 5 dollars. A lot cheaper than the 32 dollars for a ready to go board.
I also found this fairly simple schemetic for the chip, it really doesn't look all that complex: http://www.circuitcellar.com/library/print/0504/Bachiochi166/f1.htm
My questions are in regards to "programming" the chip. What exactly are you programming? And is programming something that can be done at home with homebrewed equiptment? I found this link for a homebrew programmer: http://translate.google.com/translate?u=http%3A%2F%2Fwww.cattopasto.com%2FElettronica%2FWalPIC%2FWalPIC.php&langpair=it|en&hl=en&ie=UTF-8&oe=UTF-8&prev=/language_tools which doesn't look all that difficualt to build and I found this link: http://www.ic-prog.com/index1.htm for the actual software.
But I know this sounds stupid, but what exactly is being programmed on the chip. In otherwords, is the chip not really "ready to go"?
I'm going to be using these devices for modifying old joysticks and other game controllers.
One more question along these lines, does anyone here know if its possible to hack a usb interface onto one of those little eraserhead pointer stick thingys found on most IBM Thinkpads?