Posted on May 17, 2011 at 14:03It depends on your ADC range and variation in the temperature sensor characteristics. You can find out about the sensor in the datasheet.
http://www.st.com/stonline/products/literature/ds/14611/stm32f103ze.pdf section 5.3.20
You'll see that the voltage out at 25C is typically 1.43V but it might be as low as 1.34V or as high as 1.52V. The variation with temperature (slope) varies too. All together it means you have to calibrate the sensor for each different microcontroller you get.
There are lots of better temperature sensors with I2C etc. interfaces or you can use a thermistor / resistor but watch out for the ADC input impedance requirements then.
