A temperature sensor is just an electronic chip that senses the ambient temperature around it and gives out varying voltage across the output terminal of the sensor. By using this, we can calculate the temperature that's being sensed. There are many different types of sensors available in the market, but we will be using the one that is the most easily available, and most commonly used by the hobbyist. This is the LM35 temperature sensor module, which is an analog output sensor, where the voltage can be directly converted to temperature values, based on the formula given by the manufacturer of the sensor, as mentioned in the datasheet of the sensor:
The basic principle behind the LM35 temperature sensor is that it converts the ambient temperature around the sensor to analog voltage proportionally.
In the following picture, you can see the pin terminals of the LM35 temperature sensor where one terminal is the input, which gets supply input voltage...
