DHT11 vs DHT22: Datasheet, Pinout, and Features

The DHT11 is a commonly used temperature and humidity sensor that comes with a dedicated NTC to measure temperature and an 8-bit microcontroller to output the values of temperature and humidity as serial data. The component is a 4-pin single-row pin package. It is convenient to connect and special packages can be provided according to users’ requests.

DHT22 output calibrated digital signal. It utilizes exclusive digital-signal-collecting-technique and humidity sensing technology, assuring its reliability and stability. Its sensing elements are connected with an 8-bit single-chip computer. Every sensor of this model is temperature compensated and calibrated in an accurate calibration chamber and the calibration-coefficient is saved in the type of program in OTP memory, when the sensor is detecting, it will cite coefficient from memory.

DHT11 Pinout

DHT22 Pinout

The DHT11 and DHT22 are commonly used Temperature and humidity sensors. The sensor comes with a dedicated NTC to measure temperature and an 8-bit microcontroller to output the values of temperature and humidity as serial data. The sensor is also factory calibrated and hence easy to interface with other microcontrollers.

The sensor can measure temperature from 0°C to 50°C and humidity from 20% to 90% with an accuracy of ±1°C and ±1%. So if you are looking to measure in this range then this sensor might be the right choice for you.

The DHT11 and DHT22 Sensors are factory calibrated and output serial data and hence they are highly easy to set it up. The connection diagram for this sensor is shown below.

As you can see the data pin is connected to an I/O pin of the MCU and a 5K pull-up resistor is used. This data pin outputs the value of both temperature and humidity as serial data. If you are trying to interface DHT11 and DHT22 with Arduino then there are ready-made libraries for them that will give you a quick start.

• Measure temperature and humidity

• Local Weather station

• Automatic climate control

• Environment monitoring

• Ultra-low-cost

• 3 to 5V power and I/O

• 2.5mA max current use during conversion (while requesting data)

• Good for 20-80% humidity readings with 5% accuracy

• Good for 0-50°C temperature readings ±2°C accuracy

• No more than 1 Hz sampling rate (once every second)

• Body size 15.5mm x 12mm x 5.5mm

• 4 pins with 0.1" spacing

• Low cost

• 3 to 5V power and I/O

• 2.5mA max current use during conversion (while requesting data)

• Good for 0-100% humidity readings with 2-5% accuracy

• Good for -40 to 80°C temperature readings ±0.5°C accuracy

• No more than 0.5 Hz sampling rate (once every 2 seconds)

• Body size 15.1mm x 25mm x 7.7mm

• 4 pins with 0.1" spacing

Though DHT22 is more precise, more accurate, and works in a bigger range of temperature & humidity; there are three things where the DHT11 beats the hell out of DHT22. It’s less expensive, smaller in size, and has a higher sampling rate. The sampling rate of the DHT11 is 1Hz i.e. one reading every second, while the sampling rate of DHT22 is 0.5Hz i.e. one reading every two seconds.

However, the operating voltage of both sensors is from 3 to 5 volts, while the max current used during conversion (while requesting data) is 2.5mA. And the best thing is that DHT11 and DHT22 sensors are ‘swappable’ – meaning if you build your project with the one you can just unplug it and use another. Your code may have to adjust a little bit at least the wiring is the same!