Issues
NES Light Gun
The biggest issue we had in implementing this project involved the NES light gun. We had originally planned on using the light gun as an input device for a second player to shoot obstacles in the road. However, we were unable decipher the gun's cryptic signals. Specifically, we were unable to distinguish between a trigger pull and detection from the light sensor. Even though these signals were on separate wires, there was so much noise that both lines would change when either signal occurred.
I2C
Another issue we had was in getting the I2C controller in the MPC823 CPM to work in order to initialize the ADV7176 video encoder. Due to the lack of documentation on the controller, we were unable to find an example of the exact steps that were needed to communicate with the video encoder. Luckily, we had access to the code from the MicroPlot project from last term which also used the video controller. This code allowed us to add several steps that we were missing and otherwise would have never figured out due to lack of documentation.
Bad Video Encoders
Finally, we were only able to use the video controller successfully on two different lab stations. This caused numerous problems until we determined which video encoder chips were fully functional.