Would you like to find the appropriate sensor for your personal DIY project based on the Arduino microcontroller? Well, choosing the right sensor requires research as well as facilitate this process, you’ll find each of the info you need in this article. But when there’s something better from the DIY culture than theory it’s practice.

Introduction

Temperature sensors are popular to sense the temperature in a environment. All of them function inside a similar way, but have slightly different features. According to these functions, I’ll take you step-by-step through the best practice of picking the right temperature sensor for your project by having an Arduino microcontroller.

If you are already a champion of measuring the temperature and merely want a tad bit more information, or you are considering digging deep into the Arduino temperature monitoring space, these 11 temperature sensors should cover all kinds of temperature sensors found in robotics and automation.

Temperature sensors comparison of numbers: DS18B20, LM35DZ, DHT11, thermocouple sensor, MLX90614, LM75, SHT15, TMP100, RHT03, TPA81, D6T MEMS

Temperature sensors comparison of numbers: DS18B20, LM35DZ, DHT11, Thermocouple Type-K, MLX90614, LM75, SHT15, TMP100, RHT03, TPA81, D6T MEMS

Applications

Since it matters what kind of project you’re trying to find, I really hope to obtain something listed that could help you:

fire fighting robot able to discover the supply of fire and do something;

a mobile robot capable to detect to check the temperature and send data via Bluetooth or Wi-Fi to your server and look at the temperature information on a smartphone or even a tablet;

a wireless sensor network at your residence to take decisions and controls the heating and air-con unit;

a security alarm system that senses the actual existence of a human;

Temperature sensors for hobbyists

The temperature sensors for hobbyists are cheap in comparison to the sensors normally, nevertheless they serve a similar purpose – reading the temperature. Well, none of such sensors can eat the sun, but are fantastic for homemade robotics and automation applications since they are easy to interface, accurate, and it has a speedy response time. When you place your finger onto it, immediately the output of the sensor starts to rise.

In this area of the article, I’ll examine deeply the functions, price, the best way to interface the sensor along with the best applications for each and every sensor.

1. DS18B20

The DS18B20 is actually a cheap digital temperature sensor using a price of only $3.95. The sensor is used in a wide variety of hobbyist applications for both beginner as well as others that happen to be more skillful.

This sensor has 1-wire interface, which means require merely one pin to speak with all the microcontroller. More than this, it can be developed with an exclusive serial number that permits you to interface more sensors about the same data bus.

The accuracy from the measurements is high since the sensor fails to depend upon the precision of your microcontroller to measure the analog signal. And since this sensor features a digital output, you will not have any signal degradation even over long distances.

The sensor is commonly used in a large collection of applications including temperature sensing and monitoring robot, air temperature monitors, etc.

Note: The DS18B20 has a waterproof version designed to appraise the temperature in wet condition. This sensor is jacketed with PVC, and all you know about interface and specifications continues to be the same.

This tutorial helps guide you to wire the sensor with an Arduino UNO board and study the temperatures detected with the sensor. Within the sketch is called the DallasTemperture library that allows you to use this sensor super easy: Arduino – One Wire Digital Temperature Sensor – DS18B20.

2. LM35DZ

Sometimes I don’t think that we can buy sensors at a price under a coffee. The LM35DZ is one of the cheapest temperature sensor from the DIY community. It possesses a value of only $1.57.

The sensor is calibrated directly in Celsius degrees, and the only functional mode may be the analog output directly proportional to temperature.

This is basically the ideal sensor for Arduino projects because it can be powered directly with 5V through the Arduino’s power pin and contains only three pins (one pin is made for analog output as well as 2 for power source).

Having a sealed circuit, the sensor can not be exposed to oxidation which is often employed to measure the temperature of water accurately. On the whole, the sensor is commonly used for easy projects to showcase with an LCD the current temperature to advanced robots capable of detect the fire in the room, warehouse or perhaps a forest.

In this particular tutorial, you see the scheme of the circuit with all the circuit connection as well as the Arduino sketch to show the temperature detected through the sensor in Celsius and Fahrenheit degrees. To explore more the LM35DZ features, the Instructables user HarshV demonstrates how to develop a computerized cooling system.

3. TMP100

The TMP100 has three features which make it one of the better temperature sensors for DIY projects. The 1st feature is the fact that sensor supports an input voltage of 2.7V to 5.5V, that is in opposition to the TMP102 sensor that needed an input voltage between 1.4V and three.6V. The second feature may be the two address pins that allow you to control around eight sensors on one I2C bus. The third important feature is its waterproof property that managed to get good to read through the temperature in damp or dry location. Also, the sensor could be installed on a horizontal deck or upside down.

If it leaves the Texas Instruments factory, the sensor is a tiny and compact chip that looks such as a spider with six legs. To function quicker with the TMP100 sensor, I recommend you try using a breakout board. The DFRobot small breakout board using a built in TMP100 sensor is a superb option at a cost of $11.55.

The same online shop teaches you within a tutorial the way to interface the TMP100 breakout board having an Arduino clone and browse the temperature detected.

4. DHT11

At a cost of $5.33, the DHT11 has cost/performance advantages and is also a somewhat cheap sensor to study the temperature and humidity. It’s a sensor having an good quality though with an actual downside since search for digital signal once every 2 seconds.

Otherwise, it’s fairly easy to embed the sensor within your project and to monitor the surrounding air.

The DHT sensor has two versions: DHT11 and DHT22. Both sensors are very good to appraise the temperature and humidity, although the characteristics are different.

In comparison to DHT11, the DHT22 is nice to study the temperature from -40 to 125°C and it has a greater accuracy than DHT11. But even it cannot read a wide variety of temperature, the DHT11 is smaller and much less expensive than DTH22.

With this tutorial, you discover information how to wire the sensor, install the DHT11 library and display on Arduino’s Serial Monitor the values generated through the sensor.

From reading to displaying the temperature upon an LCD screen is a matter of minutes. If you wish to try something other than a straightforward reading temperature application, you can try a method to determine the temperature and humidity of your room and display the values recorded on an LCD display as well as a web page.

5. RHT03 (DHT22)

RHT03 (also called SHT22) is actually a digital temperature and humidity sensor that comes calibrated and doesn’t require additional components to keep track of the environment in the room or warehouse. The sensor is simple to operate with any Arduino microcontroller and has a value of $9.95.

Compared to its little brother DHT11, the DHT22 is much more accurate and might browse the temperature and humidity more often than once every second or two.

This tutorial explains all the information to interface and display the humidity and temperature recorded from the sensor.

6. LM75

LM75 is yet another inexpensive digital sensor by using a value of only $2.21. This sensor has two important features: it really is inexpensive and designed as an I2C temperature chip.

The sensor can be a surface mount device, and you must solder wires onto it. It is actually a good sensor for hobbyists and students to learn how to monitor the temperature.

In this guide, you discover an Arduino sketch to display the temperature recorded with the sensor.

Temperature sensors for automation & process control

Temperature sensors for automation and process control are expensive compared to hobbyists and temperature sensors normally, and therefore are usually used to monitor the temperature in environments with great fluctuations or perhaps for precise data logging.

In this particular area of the article, I’ll examine deeply the characteristics, applications and the ways to use each temperature sensor (SHT15, Thermocouple Type-K) for automation and process control with all the Arduino microcontroller.

Temperature sensors for automation & process control (SHT15, Thermocouple Type-K)

Temperature sensors for automation & process control (SHT15, Thermocouple Type-K)

7. SHT15

SHT15 can be a precise humidity and temperature sensor built to operate in environments with greater fluctuation in humidity and temperature. At a cost of $41.95 on Robotshop, the sensor comes fully calibrated and with 2-wire digital interface.

With this tutorial, you will learn the way to get the temperature and humidity recorded through the sensor.

8. Thermocouple Type-K

A lot of the temperature sensors with this article cannot reach higher temperatures than 125 C degrees. The Thermocouple Type-K is unique and works on higher operating temperature than most sensors.

Considering its features, it is actually supposed to are more expensive than some other sensor. In fact the thermocouple is a straightforward blend of two sensitive metals and contains a price of just $9.95.

It has a simple digital 2-wire interface and measure not more than 1 meter (around 3 feet). The sensor requires an amplifier such as MAX31855 that output an electronic digital signal to the Arduino microcontroller.

Combined with an Arduino board, the Type-K sensor can be used to look at the temperature in heaters and boilers, HVAC systems, etc.

The Adafruit tutorial shows you how to wire the Thermocouple together with the MAX31855 amplifier and display the temperature detected through the sensor.

Temperature sensors for projects with special needs

DS18B20, TMP100, or DHT11 tend to be a good option in order to monitor the temperature in a room and out in a forest consequently making you satisfied with any project. But what if you wish to detect the movement or the number of persons in a room? In this category enters three of the special temperature sensors.

All the sensors incorporated into this area of the article are used in special projects because works different and study the temperature not the same as whatever we may have learned about classic temperature sensors.

Temperature sensors for projects with special needs (MLX90614ESF, TPA81, D6T MEMS)

Temperature sensors for projects with special needs (MLX90614ESF, TPA81, D6T MEMS)

9. MLX90614ESF

The MLX90614ESF sensor senses the temperature by sending infrared light to remote objects. For the reason that sensor sends infrared waves, it could sense the temperature of your object without touching them physically.

By using a value of $19.95, the sensor is easy to use, has good accuracy and high resolution.

The sensor is ideal for a variety of applications and especially when must measure the temperature over a 90-degree field of view.

Communication with the MLX90614 is achieved through two ways of output: PWM and SMBus.

Here is an illustration demonstrating the use of MLX90614ESF sensor. It produces an elementary application that allows you to look at the infrared sensors at your workplace.

10. TPA81

The infrared sensor with built-in lens, coupled with increasingly sophisticated module to appraise the temperature of eight adjacent points simultaneously, might be able to some fascinating things.

You may set it to detect the temperature of any body system or perhaps a candle flame at a variety of 2 meters (around 6 feet).

The sensor includes a value of $105.44 and communicates by using a development system with the I2C interface.

This tutorial covers the software and hardware setup necessary to connect the TPA81 sensor having a microcontroller. The sensor makes possible the temperature detection in dexopky90 large assortment of applications for example the NAO humanoid robot which uses the TPA81 thermal sensor to detect the high temperature source.

11. D6T MEMS

Perhaps you want something to take place when nobody’s home or perhaps you enter an area, like to have the lights turned off or on. Operating around the infrared waves, you will notice the DT6 sensor as being the logical following step for monitoring an area, security or safety monitoring.

This little smarter sensor can count the quantity of folks a room, regardless of whether none of them moves.

The sensor features a cost of $49.88 and communicates with all the Arduino microcontroller via an I2C interface.

This PDF file will teach you ways to get the measurement values from your infrared sensor.

Failure mode

Its not all temperature sensors are created equal and quite often they could read high or low temperatures. When you don’t actually know if it’s a sensor failure, you have to check below the most common failure mode of a temperature sensor.

1. Sensor heated through the electronics

This might be one of the most common errors when using a sensor to check or detect the temperature. When the sensor is heated from the electronics, the sensor will never report the correct temperature. Initial step would be to localize the heating or move the sensor away from enclosure.

2. Library error

By using the Arduino to measure the temperature in the sensor, in the Arduino sketch is known as library suitable for the sensor. You need to be certain that the library in the sketch is one that retain the sensor type.

3. Temperature exceeds the max temperature

This is one of the worst scenarios for any system that measure the temperature. Usually, the company writes inside the datasheet from the sensor what happens in case the temperature exceeds the maximum temperature maintained by the sensor. From the worst, whenever your sensor reached the highest temperature, your chip might take an internal damage or might melt.

Tips: Always is good to select a sensor that will support all of the temperatures assumed to be measured. All of the sensors explored in the following paragraphs usually are more accurate if the temperature reaches the values from the middle of the range.

4. Correct conversion between Celsius and Fahrenheit

You must create the right conversion between Celsius to Fahrenheit or Fahrenheit to Celsius. Within the datasheet from your manufacturer, you find the sensor info on measurements.

5. Heat conducted down the wire

In case your sensor is in contact with a wire, the wire can conduct a surprising volume of heat. The contact involving the wire and sensor can be an issue, particularly if you monitor the temperature along pipes.

6. Condensation in the morning

Condensation in the morning can destroy your project or perhaps your expectations with regards to the temperature measurements. The condensation appears in every single morning when warm moist air meets the cooler dry air. In cases like this, the liquid vapors can condense on electronics likewise it does on grass. Therefore, if you think that your project is in contact with condensation, you have to use materials that keep water vapor condensation from as a problem.