User Manual

91
Lesson 18 Temperature Sensor
Introduction
A temperature sensor is a component that senses temperature and converts it into output
signals. By material and component features, temperature sensors can be divided into two
types: thermal resistor and thermocouple. Thermistor is one kind of the former type. It is made
of semiconductor materials; most thermistors are negative temperature coefficient (NTC)
ones, the resistance of which decreases with rising temperature. Since their resistance
changes acutely with temperature changes, thermistors are the most sensitive temperature
sensors.
There are two kinds of thermistor module in this kit (as shown below).
Analog temperature sensor Thermistor
Components
- 1 * Raspberry Pi
- 1 * Breadboard
- 4 * Jumper wires (Male to Male, 2 red and 2 black)
- 1 * Network cable (or USB wireless network adapter)
- 1 * Analog-temperature Sensor module
- 1 * Thermistor module
- 1 * PCF8591
- 1 * 3-Pin anti-reverse cable
- 1 * 4-Pin anti-reverse cable
- Several Jumper wires (Male to Female)
Experimental Principle
This module is based on the principle of the thermistor, whose resistance varies significantly
with ambient temperature. When the ambient temperature increases, the resistance of the
thermistor decreases; when decreases, it increases. It can detect surrounding temperature
changes in a real-time manner.
In this experiment, we use an analog-digital converter PCF8591 to convert analog signals into
digital ones.