If you need a temperature sensor but don’t have one at hand, here’s an easy way to create one, using a .. diode ! All what you have to do is to bias the diode with a current around 1 mA, and to measure it’s forward voltage drop.
The forward voltage of a silicon diode varies with about -2 mV / °C. So, basically the diode itself can be used as a temperature sensor. In order to have a good precision, you should perform a calibration by measuring the output voltage at a known temperature. Continue reading