Is the PIC in the Vex Micro Controller the same PIC that is used in the FRC RC. If so, do the analog inputs have 10bit resolution as well, or just 8?
You are correct. Both Controllers use the PIC18F8520 and have 10 bit A/D resolution up to the 2005 RC. 2006 and newer FRC RCs have a different processor.
By any chance, does anyone know what the input impedance of the analog inputs are on the Vex controller? I am trying to design a custom circuit to do complementary filtering of two signals and this value will need to be taken into account.
We have updated the “Inputs and Outputs” section of the Vex Micro Controller Specifications to include Input Impendence, see http://www.vexlabs.com/vex-robotics-design-system.shtml
How can a Vex monitor its own battery voltage?
You can do this by designing a voltage divider external to the Microcontroller and connecting the reduced voltage level to an Analog Input. A voltage divider must be used because the voltage to the Analog Input must not exceed 5V or damage can result.