Vasquo, thanks for running down the link. Good info is always useful, :-). Will be
interested, along with G_M, on hearing what the surprises are.
Personally, I don't use "star grounding"... because it's impossible to implement on a complex PCB.
Also, I don't necessarily buy this statement. The first step is to partition the areas of
the pcb used for power supply, digital circuitry, motor circuitry [if used], and analog
circuitry. Then, I think, you can still use star-grounding on most of it, although you
might play with where the analog ground is connected over.
Also, both PIC and ATmega chips use a compromise, in that they specify using a
low-pass filter on the AVCC pin, even if there is no specific AGND pin on the chip.
Also, I imagine the exact best point for making the analog ground connection is
mainly important for cases where ADC resolution is 12-bits and more, although I have
no specific evidence for this.