- Analog TMP36/LM335 -- they are easier to use (just read from ADC), but what to do with AREF? MCU is powered from 3 AA batteries, so reference voltage will be not stable.
# INTERNAL: an built-in reference, equal to 1.1 volts on the ATmega168 or ATmega328 and 2.56 volts on the ATmega8 (not available on the Arduino Mega)
Topic about protecting DS18B20 is also mine
The only problem with DS as mentioned before is program size as ur using atmega8.