# In order to get 16 good a/d bits, the circuit board must be laid out so as to minimize noise. All grounds must go to a central terminal point in a "star" configuration. All chips must have bypass capacitors on their power pins. In addition, the PIC14000 is programmed so that it goes to "sleep" during a/d operations to minimize digital noise in the circuit.
# SAMPLING RATE - The 4 MHz PIC14000 can perform 16 bit A/D at about 60 samples per second (SPS) and these samples can be averaged in software for noise rejection. I have written the firmware to allow for a dip switch selection of averaging times from 4 SPS to 35 SPS.