Temperature Sensors？Logging for Arduino: Which Sensor to choose?
With many temperature sensors with different features and functions out in the market, it is hard to pick which temperature sensor to use for your Arduino project. No worries, as by the end of this guide you will learn about the various temperature sensors functions, applications, accuracy, temperature range, and many more!
In this guide, we will be seeing the different kinds of temperature sensors to use for your Arduino projects. Some popular temperature sensors used by many hobbyists will be listed down below if you would like to get them for yourself.
- Thermistor Sensor
- DHT and AHT Sensors
- Waterproof temperature Sensor
- Barometric Sensor
- Gas Sensor
All of these sensors are available for purchase in our online store! – Seeed Studio Bazaar, The IoT Hardware enabler.
As you can see, some of the sensors are part of our Grove system.
Grove is a modular, standardized connector prototyping system that takes a building block approach to assemble electronics. Compared to the jumper or solder based system, it is easier to connect, experiment and build which simplifies the learning system! To learn more about Grove system, you can check out our Wiki!
Which Temperature Sensor should you pick for your Arduino?
Before you can make a decision on which sensor to pick, you need to understand the different kinds of sensors available first. The two most common temperature sensors for hobbyists are Thermistor and DHT. If these don’t fit your requirements, there are other temperature sensors that include different kinds of features. Find out more below.
Thermistor: Thermistor is a combination of the word thermal and resistor. Ultimately, it is a special type of resistor that is temperature-dependent. Meaning, the resistance of the resistor changes according to the temperature. Thermistors are very accurate and cost-effective for measuring non-extreme temperatures (~-40°C – 100°C). Thermistors are only able to log temperature data so this is the best to pick if you’re looking for a cost-effective and reliable way to log non-extreme temperature data.
DHT and AHT: DHT and AHT sensors work the same. AHT sensors is a new and improved version of DHT sensors. These sensors are made of two main parts – a thermistor and a capacitive humidity sensor. This means that DHT and AHT sensors can log not only temperature data but also humidity data. There is then another chip inside these sensors to convert the analog signal from the sensors to digital signals. Essentially, it is a thermistor sensor that has an added humidity sensor. If you’re looking for a cost-effective and reliable way to log both non-extreme temperature (~-40°C – 80°C) and humidity data, this is the best pick. DHT sensors are also the most popular among Arduino users.
Waterproof Sensors: Waterproof temperature sensors are also available for monitoring water temperature. These sensors are able to log a wider range of temperatures (~-50°C – 120°C).
Others:
Barometric Sensors: Barometric sensors are capable of logging both air pressure and temperature data.
Gas Sensors: Temperature sensors that are capable of logging Temperature, Humidity, Pressure and Gas data.
There are no best temperature sensors, but there is a best temperature sensor for what you’re trying to accomplish. Ultimately, it depends on what your project requires.
With that, let’s see what are the more popular temperature sensors for each category!
Thermistor Sensor
Grove – Temperature Sensor ($2.90)
- The Grove – Temperature Sensor uses a Thermistor to detect the ambient temperature.
- The detectable range of this sensor is -40ºC – 125ºC, and the accuracy is ±1.5ºC
If you are a beginner looking for a basic temperature data logger, this Grove – Temperature Sensor will do a great job at an affordable price tag.
DHT and AHT Sensors
Grove – Temperature & Humidity Sensor (DHT11) ($5.90)
- The DHT11 is a basic, ultra low-cost digital temperature and humidity sensor.
- DHT11 is the most popular temperature and humidity module for Arduino and Raspberry Pi due to its many advantages.
- E.g. Low power consumption and excellent long-term stability. Relatively high measurement accuracy can be obtained at a very low cost.
- Our Grove – Temperature & Humidity Sensor is a high quality, low-cost digital temperature and humidity sensor based on the new DHT11 module.
- It features a single-bus digital signal output through the built-in ADC, which saves the I/O resources of the control board.
- It features a humidity range of 5% to 95% RH with a ±5% and also a temperature range of -20℃ to 60℃ with a ±2%.
As mentioned, our Grove – Temperature & Humidity Sensor uses the upgraded version of DHT11. So what is the difference?
Temperature-Humidity Sensor-DHT22(AM2302) ($4.99)
- The AM2302 Humidity Capacitance Digital Temperature and Humidity Module is a temperature and humidity composite sensor with a calibrated digital signal output.
- The sensor consists of a capacitive sensing element and a high precision temperature measuring element connected to a high-performance 8-bit microcontroller.
- Therefore, the product has the advantages of excellent quality, ultra-fast response, strong anti-interference ability, and high-cost performance
- The DHT22 sensor is ultra-small size, extremely low power consumption, and with a signal transmission distance of more than 20 meters making it very versatile in terms of application.
- The product is also easy to connect with 3 leads (single bus interface). If you want to connect your sensor with a longer wire, you can easily just add a pull-up resistor.
- The DHT22 features a humidity range of 0% to 100%RH with a ±2% and temperature range of -40℃ to 80℃ with a ±0.5%.
Grove – Temperature & Humidity Sensor Pro (DHT22/AM2302)
- Part of the Grove system, there is another temperature sensor featuring the DHT22 module as well.
- The difference lies in this sensor having a breakout board with a Grove connector. This is for easier connectivity to a Seeeduino or Grove compatible shield. Much convenience, hooray!r
- This sensor also features a humidity range of 0% to 100%RH with a ±2% and temperature range of -40℃ to 80℃ with a ±0.5%.
These DHT sensors are perfect for home projects like weather stations, environmental automatic control systems, testing/inspection of equipment, farm/garden monitoring systems and many more!
Overall, the DHT sensors are basic and slow temperature and humidity sensors that are suitable for beginners and hobbyists looking to do basic data logging. The DHT22 is more accurate with a larger range compared to the DHT11 but comes at a bigger price. If you are looking for something more accurate with a larger range, go for the DHT22 if not the DHT11 will work fine too!
Grove – AHT20 I2C Industrial Grade Temperature and Humidity Sensor
- Launched in early 2020, this temperature sensor is based on the AHT20 module, by Aosong, also the creator of DHT11 and DHT22.
- The newly equipped internals of the AHT20 allows its performance to be ameliorated from the previous generation of sensors.
- The AHT20 features a humidity range of 0% – 100% with ± 2% RH accuracy and a temperature range of -40℃ – 85℃ with a ± 0.3 ℃ accuracy.
If you need more precise data that the DHT series sensors can’t provide, the AHT20 will be the right pick for you. Find out more details on our other blog.
Waterproof Temperature Sensor
One Wire Temperature Sensor (DS18B20) ($7.50)
- The DS18B20 is a digital thermometer that provides 9-bit to 12-bit Celsius temperature measurements.
- It has an alarm function with non-volatile user-programmable upper and lower trigger points.
- This is a 2m long One Wire Temperature Sensor which has a waterproof probe and long wire shape, suitable for immersive temperature detection.
- It is widely adopted and documented for use with the Arduino.
- To get this sensor working, you will need to add extra resistance to get it working which we did by adjusting it into a Grove port and had a resistance pre-assembled inside so that you can use it as a regular Grove sensor.
- This makes it an easily connected one wire temperature sensor for Seeeduino, which is derived from Arduino and compatible with all Arduino platforms.
- Some features of this DS18B20 sensor includes
- Waterproof
- Requires only one wire for data interface
- Grove Compatible
- Accepts 3.0V to 5.5V power supply
- Wide temperature range of -55°C to +125°C
- High accuracy of ±0.5°C (-10°C to +85°C)
As this DS18B20 temperature sensor is waterproof with a wide temperature range and high accuracy, they are very suitable for outdoor projects or for measuring liquid temperature. Some projects include Sous Vide cooking, solar boiler, and many more. However, the DS18B20 uses the Dallas 1-wire protocol which requires some coding to get it to work. This makes it slightly less beginner-friendly.
You can check out our other blog on DS18B20 to know more about this sensor!
Barometric Sensor
Grove – Barometer Sensor (BMP280) ($8.90)
- The BMP280 sensor is a barometric pressure sensor specially designed for mobile applications by Bosch.
- It features high accuracy, linearity as well as long term stability and high EMC robustness.
- The Grove BMP280 Barometer Sensor is built around Bosch BMP280, a low-cost and high-precision environmental sensor that measures temperature and barometric pressure.
- The air pressure can be measured in a range from 300 hPa to 1100hPa with ±1.0 hPa absolute accuracy. As for the temperature, the sensor works perfectly for temperatures between – 40℃ and 85℃ with an accuracy of ±1℃.
- Due to the high accuracy measurement of barometric pressure, the altitude can be calculated as well as barometric pressure and altitude is inversely proportional. The altitude can be measured up to a ±1 meter accuracy.
- Another great thing about this module is that you don’t even need to worry about the I2C collisions as it provides both I2C and SPI interfaces. To use SPI, simply de-solder the bonding pads on the back. If you go with I2C, the board also provides 2 I2C addresses for you to select as you want.
Grove – Environmental Sensor (BME280) ($17.00)
- The BME280 sensor is an integrated environmental sensor developed specifically for mobile applications where size and low power consumption are key design constraints.
- They share similar features to the aforementioned BMP280 but are not entirely the same.
- The unit combines individual high linearity, high accuracy sensors for pressure, humidity, and temperature, designed for low current consumption, long term stability and high EMC robustness
- The Grove – Environmental Sensor (BME280) is built around the Bosch BME280.
- Grove BME280 provides a precise measurement of not only barometric pressure and temperature, but also the humidity in the environment.
- The air pressure can be measured in a range from 300 hPa to 1100hPa with ±1.0 hPa accuracy, while the sensor works perfectly for temperatures between – 40℃ and 85℃ with an accuracy of ±1℃. As for the humidity, you can get a humidity value with an error of less than 3%.
- Similarly to the BMP280, it can measure altitude with a ±1 meter accuracy, which makes it a precise altimeter as well.
- In addition, you don’t need to worry about I2C collisions as it provides both I2C and SPI interfaces.
So what are their differences?
- The Grove BMP280 is similar to Grove BME280, and their parameter performance is almost the same, so people are often confused.
- The BMP280 can only measure temperature and air pressure, while the BME280 can measure humidity in addition to temperature and air pressure.
- Because of this difference, BMP280 is much cheaper than BME280.
- If you’re looking to measure only the atmospheric pressure, then we recommend the Grove BMP280. However, if you want to monitor the environment more comprehensively, then we recommend Grove BME280.
Some projects and uses of these barometric sensors include weather stations, environmental automatic control systems, altimeter and many more!
Gas Sensor
Grove – Temperature, Humidity, Pressure and Gas Sensor (BME680) ($20.50)
- The BME680 is an expansion on Bosch Sensortec’s existing family of environmental sensors. The BME680 integrates for the first time high-linearity and high-accuracy gas, pressure, humidity and temperature sensors where the gas sensor within the BME680 can detect a broad range of gases to measure air quality for personal well being.
- The Grove-Temperature & Humidity & Pressure & Gas Sensor(BME680) is based on the BME680 module. The 4-in-1 function is integrated on such a small module, allowing it to be very beneficial to apply on IoT or GPS devices.
- It features low power consumption, wide measurement range and has an optional output that allows individual humidity, pressure and gas sensors to be independently enabled/disabled.
- Gases that can be detected by the BME680 include Volatile Organic Compounds (VOC) from paints (such as formaldehyde), lacquers, paint strippers, cleaning supplies, furnishings, office equipment, glues, adhesives, and alcohol.
- Find out more details and specifications of the BME680 below!
Some uses and applications of the BME680 include environment domestic safety (indoor air quality), household application (home automation and control), weather forecast, GPS enhancement (e.g. time-to-first-fix improvement, dead reckoning, slope detection) and many more!
Summary
With so many types of temperature sensors with various functions and applications, we have compiled a table for you guys to easily pick the temperature sensor that best fit your Arduino project!
| Sensor | Thermistor | DHT11 | DHT22 (AM2302) | AHT20 | One Wire Temperature Sensor (DS18B20) | Grove – Barometer Sensor (BMP280) | Grove – Environmental Sensor (BME280) | Grove – Temperature, Humidity, Pressure and Gas Sensor (BME680) |
| Measures | Temperature | Temperature, Humidity | Temperature, Humidity | Temperature, Humidity | Temperature | Temperature, Pressure | Temperature, Humidity, Pressure | Temperature, Humidity, Pressure, Gas |
| Communication Protocol | One-wire (single bus interface). | One-wire (single bus interface). | One-wire (single bus interface). | I2C | One-Wire (single bus interface). | I2C, SPI | I2C, SPI | I2C, SPI |
| Supply Voltage | 3.3V to 5V | 3.3V to 5V | 3.0V to 6V | 2.0 to 5.5V | 3.0V to 5.5V | 3.3V to 5V | 3.3V to 5V | 3.3V to 5V |
| Temperature Measurement Range | -40°C to 125°C | -20℃ to 60℃ | -40ºC to 80ºC | -40ºC to 85ºC | -55°C to 125°C | -40°C to 85°C | -40℃ to 85℃ | -40℃ to 85℃ |
| Temperature Measurement Accuracy | ± 1.5°C | ± 2% | ±0.5% | ± 0.3 ℃ | ±0.5°C | ±1°C | ±1℃ | ±1°C |
| Other Measurements Range and Accuracy | – | Humidity Range: 5 to 95%RHHumidity Accuracy: ±5% | Humidity Range: 0 to 100%RHHumidity Accuracy: ±2% | Humidity Range: 0 to 100%RHHumidity Accuracy: ±2% | – | Barometric Pressure Range: 300 – 1100 hPaBarometric Pressure Accuracy: ±1.0 hPa | Barometric Pressure Range: 300 – 1100 hPaBarometric Pressure Accuracy: ±1.0 hPaHumidity Range: 0% – 100% RHHumidity Accuracy: ±3% | Barometric Pressure Range: 300 – 1100 hPaBarometric Pressure Accuracy: ±1.0 hPaHumidity Range: 0% – 100% RHHumidity Accuracy: ±3%VOC Gas Sensor (eg. Ethanol, Alcohol, Carbon Monoxide) |
| Price | $2.90 | $5.90 | $4.99/$9.90 | $4.90 | $7.50 | $8.90 | $17.00 | $20.50 |
What are your thoughts on this list of temperature sensors? Do you have another temperature sensor you want to see added to this list? Do let us know in the comments section down below!
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