I'm fairly new to Arduino projects, and only recently did I acquire an Intel Galileo board. One thing that has bugged me during my initial experiments is that I am unable to reach the maximum read value (1023) with the analogRead() function. With A0 pin shorted to 5V, the returned value is roughly 996~997. Same thing does not happen with ground, I get 0 when I short A0 to ground. Why exactly can't I have the full 1024 range of the ADC?
I've also noticed in Galileo's datasheet that apparently external voltage references are not allowed and the AREF pin is disabled. Does this have anything to do with the ADC limited range problem?