So, my wife has(had) an old cell phone that has one of those slide out QWERTY keypads. She graciously donated it to me
My plan is to hopefully somehow convert the keypad part into a keyboard for the Raspberry Pi. This is how far I've gotten so far.
Upon further inspection and with a little research, I've found the controller for it, which isn't exactly a controller in what you would normally find in a keyboard, but an I2C Key Switch Controller. The MAX7359, basically, just manages key presses and send it to the microprocessor in the cell phone over I2C. It operates off of 3.6V max, which is perfect, as the Pi can provide 3.3V.
My task now is to figure out how to do the following -
1. Find a way to solder leads to the IC. Very very small!
2. I have the datasheet. Figure out how to interface and communicate with it via the Pi.
3. Begin a crash course in learning to write a program for the Pi to get this little gizmo up and running as a keyboard.
These are my aspirations. Chances are, it won't go any further than this, but I remain hopeful!