Back in 2005, a member of a French robotics team named [Laurent] wrote a wonderful how-to that we somehow missed on using the Game Boy Camera as a vision device for a robot. The images above are actual shots from his project. The Game Boy Camera features a stunning 128×123 pixel resolution in a gorgeous 4 color gray-scale palette. Possibly the most attractive feature of this hack is that it is still possible to get a hold of these cameras for under ten dollars on ebay.

He connected the camera sensor to an Atmel AT90S4433 using a combination of digital and analog signals, and then used the microcontroller to echo the data back to his PC. His write up includes schematics for wiring up the sensor/microcontroller, the datasheet for the sensor, his C code for the whole project, and an easy to read pin out of the GBC connector. Although his project simply offloaded the image to a computer, it would be entirely possible to have the microcontroller respond to the image or simply just log and store it. It would also be just as easy to replace his Atmel chip with your own favorite microcontroller, as long as it has a couple Digital I/O ports and at least one Analog port (or an external analog to digital converter).

UPDATE: Good catch r4v5, it would require an ADC, not a DAC.