[Qbranch]

You have datatyping issues. The result of Get_Analog_Value() (if its like the one in the '06 controller) returns an unsigned integer... and your dividing by a floating point... and assiging to an unsigned character!

You might try:

{
unsigned int temp;
temp = Get_Analog_Value(Compass);
temp *= 4023; //fraction version of
temp /= 1000; //your conversion factor - avoid floating point
pwm13 = (unsigned char)temp;
printf("%d", pwm13);
}