In this article, we will look at Arduino’s popular temperature sensors which are the foundation for Arduino’s entry level projects.
Temperature Sensor
Temperature sensors are designed to measure the temperature of an object or substance using the properties and characteristics of the object being measured.
All sensors work differently. By the principle of measurement, these devices can be divided into several groups:
- Thermocouples
- Thermistors
- Piezoelectric sensors
- Semiconductor sensors
- Digital sensors
- Analog sensors
Examples of Temperature Sensor
1. LM35 – Temperature Sensor
- LM35 is an analog sensor produced by NS (National Semiconductor) in the United States.
- Widely used sensor.
- Large temperature range (from -55 ° C to 150 ° C), high accuracy (+ -0.25 ° C) and a calibrated output.
- Cheap and convenient to connect to the circuit.
Application examples
- Remote temperature sensor.
- Used as a Celsius thermometer.
- Used as a Fahrenheit Thermometer.
- Temperature meter with voltage frequency conversion.
2. DS18B20 – WaterProof Temperature Sensor
- DS18B20 is a digital temperature sensor from DALLAS Semiconductor Corporation of the United States.
- The device is available in 3 cases – 8-Pin SO (150 mils), 8-Pin µSOP, and 3-Pin TO-92.
- It is also made in a waterproof housing with three outputs.
- The sensor is simple and convenient to use.
- It has the ability to save data when the device is turned off
Application examples
- Soil temperature detection
- Hot water tank temperature control
- It measures the liquid temperature.
- Used in industries as a temperature measuring device.
3. DHT temperature sensors
- DHT11 and DHT22 are two versions of the DHT sensor with the same pinout
- They are temperature and humidity composite sensors with digital signal output
DHT 11:
- DHT11 is characterized by the determination of temperature in the range from 0C to 50C
- The determination of humidity in the range of 20-80%
- Measurement frequency: 1 time per second.
DHT 22:
- The DHT22 sensor has the best characteristics, the range is increased – from -40С to 125С,
- It detects humidity ranging from 0-100%,
- Measurement frequency: 1 time in 2 seconds.
Application examples
- To measure humidity and temperature values in heating, ventilation and air conditioning systems.
- Used in weather stations to predict weather conditions.
- Used in offices, cars, greenhouses and industries use this sensor for measuring humidity values and as a safety measure.
4. TMP36 – Analog temperature sensor
- TMP36 is an analog sensor.
- Determination of temperature in the range from (-50°C to 125°C)
- Low cost
Application examples
- Remote temperature sensor.
- Used as a Celsius thermometer.
- Used as a Fahrenheit Thermometer.
Characteristics of Temperature Sensors
| Title | Temperature Range | Accuracy | Error | Library |
| DS18B20 | -55C … 125C | + -0.0625С | + -2% | Onewire.h |
| DHT11 | 0С … 50С | + -2C | + -2% temperature, + -5% humidity | DHT.h |
| DHT22 | -40C … 125C | + -0.5С | + -0.5% temperature, + -2 to + -5% humidity | DHT.h |
| LM35 | -55C … 150C | + -0.5С (at 25С) | + -2% | DHT.h |
| Tmp36 | -40C … 150C | + -1C | + -2% | null |
