AVR-Chat

Dear,  
  
I need to use a sensor of temperature in the avr so that he makes a 
decision in agreement with the value (using the entrance A/D). Use 
BASCOM, does anybody have some circuit (clue) with that resource? I 
am using an attiny15. In the moment use an AT90S4433 connected to a 
PC to accompany the value read in the door ADC, I placed a variable 
source 0-5V in one of the channels ADC, even so, I am not obtaining 
success. when passing the 2,5V all the channels they start to have a 
value of 1023. Excuse for English. thank you. 

Nailson