I recently got some MAX232A samples from Maxim-IC. These chips convert the TTL RS232 signals from your PIC to the RS232 voltage levels required by your PC. They make it very easy to connect your PIC with your PC. I only needed one more thing: an RS232 serial cable. I noticed I had some old RS232 serial mice lying around. I decided to break one open and remove the cable. Perfect – the cable had all the wires I needed – RX, TX and more. Let’s put this aside.
Next, there were some more interesting components inside the mouse that may come in handy, such as buttons, phototransistors, IR LEDs and so on. The IR LEDs, phototransistors and the gears could be used for something interesting.
I found a site that describes the use of the IC inside the serial mouse to extract movement information: http://www.geocities.com/kellertuberg/telescope/serial_mouse.html
Let’s see where this goes…