I want to use a PT100 to read temperatures using an ADC. I understand the basics [and more] on both sides, the PT100 and the ADC, however joining both for optimum result seems a bit tough:

- My ADC (ATmega8 to be exact) has 10bit input, which gives me 1024 sampling values.
- The input for the whole circuit is 5v (Vin).
- My temperature range is zero to 300deg, which means PT100 resistance of 100ohm at minimum and 217.25ohm at maximum.
- Theoretically, with 1024 sampling values in this temperature range I should be able to sample at 1/3 deg.
- Ideally, I would like to have 0v input when the temperature is 0deg and 5v input when the temperature is 300deg.

I used a voltage divider to make my calculations but I am wondering if there is any better approach for this. I would love some feedbacks/opinions.

Thanks,

Ronen