Description
The DHT22 (AM2302) is a high-performance, low-cost digital sensor for measuring temperature and relative humidity . It integrates a capacitive humidity sensor and a thermistor with an onboard chip to provide calibrated digital output via a single 1-wire interface, requiring no analog input pins .
Offering superior accuracy and range compared to the basic DHT11, the DHT22 measures temperatures from -40°C to +80°C with ±0.5°C accuracy and humidity from 0% to 100% RH with ±2% RH accuracy, featuring a 0.1 resolution for both . It operates on 3.3V to 5.5V and features a 0.5 Hz sampling rate (one reading every 2 seconds) .
This sensor is ideal for weather stations, HVAC systems, smart home automation, agricultural monitoring, and various IoT projects. It is commonly used with platforms like Arduino, ESP8266, ESP32, STM32, and Raspberry Pi .
Product Specifications
| Specification | Detail |
|---|---|
| Model | DHT22 (also known as AM2302) |
| Operating Voltage | 3.3V to 5.5V DC |
| Current Consumption | 2.5mA max during conversion |
| Temperature Range | -40°C to +80°C |
| Temperature Accuracy | ±0.5°C |
| Humidity Range | 0% to 100% RH |
| Humidity Accuracy | ±2% RH (max ±5% RH) |
| Resolution | 0.1°C and 0.1% RH |
| Sampling Rate | 0.5 Hz (one reading every 2 seconds) |
| Output Signal | Digital via 1-Wire bus |
| Body Size | Various (e.g., 15.1 x 25 x 7.7mm, 22 x 28 x 5mm, or 27 x 59 x 13.5mm) |
| Weight | Approx. 2.4g to 6g |
| Pinout | 1=VDD, 2=Data, 3=NC (Not Connected), 4=GND |
