Hi,
U don't need racking Ur brain! As U have connected AD595 to +/- supplies
the output below 0 degrees Celesius is -ve. There is no problem in Basic
program. PIC A/D inputs cant read below 0V or GND of +5V supply. U just connect AD595 to only +5V and let 0degree celesius be at 2.5V and modify
program for offset and it will work.Or u take one OPAMP and shift output of
AD595 to some suitable value.
Let me know if u have any other problem.
psdayama