DHT22 Datasheet – Temperature-Humidity Sensor

Part Number : DHT22, (also named as AM2302)

Function :  Temperature-Humidity sensor

Body size : 27mm x 59mm x 13.5mm (1.05″ x 2.32″ x 0.53″)

Manufacutures : AOSONG ( http://www.aosong.com )

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Description

The DHT22 is a basic, low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed). Its fairly simple to use, but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so when using our library, sensor readings can be up to 2 seconds old.

 

DHT22, AM2302 humidity capacitor module is a digital temperature and humidity have been calibrated with digital signal output of the temperature and humidity combined sensor. Its application-specific modules capture technology and digital temperature and humidity sensor technology to ensure product with high reliability and excellent long-term stability. Sensor consists of a capacitive sense element and a precision wet NTC temperature measurement devices, and with a high-performance 8-bit microcontroller connected. Therefore, the product has excellent quality, fast response, anti-interference ability, high cost and so on. Each sensor in a very precise calibration of humidity calibration chamber. Calibration coefficients stored in the microcontroller program, the sensor detects the signal processing within the process to call these calibration coefficients. Standard single-bus interface, the system integration becomes simpler and quicker. Small size, low power consumption, signal transmission distance up to 20 meters, making it a wide range of applications and even the most demanding applications is the best choice. Products are divided into 3-lead (single-bus interface), and 4-wire connection easy, free to choose any kind of bus way. Special packages can be provided according to user needs.

 

Pinout

 

Features

  • 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)
  • 4 pins, 0.1″ spacing
  • Weight (just the DHT22): 2.4g

 

 

DHT22 Arduino

DHT22 VS DHT11

DHT11

• Alimentación de 3.3V a 5VDC
• Corriente máxima 2.5mA durante la conversión
• Lectura de humedad con un +/- 5% de precisión
• Lectura de temperatura con un +/- 2°C de precisión
• Capaz de medir humedad de 20% a 80%
• Capaz de medir temperatura de 0 a 50°C
• No más de 1 Hz en velocidad de muestreo (una vez cada segundo)
• Dimensiones: 15.5mm x 12mm x 5.5mm

DHT 22

• Alimentación de 3.3V a 5VDC
• Corriente máxima 2.5mA durante la conversión
• Lectura de humedad con un +/- 2% a 5% de precisión
• Lectura de temperatura con un +/- 0.5°C de precisión
• Capaz de medir humedad de 0% a 100%
• Capaz de medir temperatura de -40°C a 125°C
• No más de 0.5Hz en velocidad de muestreo (una vez cada dos segundos)
• Dimensiones: 15.1mm x 25mm x 7.7mm

 

Reference Site

(1) https://github.com/adafruit/DHT-sensor-library

(2) http://www.electroschematics.com/11291/arduino-dht22-am2302-tutorial-library/

(3) https://create.arduino.cc/projecthub/attari/temperature-monitoring-with-dht22-arduino-15b013

 

DHT22