Temperature & Humidity Sensor Module DHT-22 Module (SKU#KY022)

DHT-22 / AM2302 Digital Temperature & Humidity Sensor Module

Product Description

The DHT-22 (also designated as AM2302) is a high-precision, low-cost digital temperature and humidity sensor breakout module designed for environmental monitoring in microcontroller projects. It utilizes a capacitive humidity sensing element and a high-precision thermistor to measure surrounding ambient air parameters, converting analog readings into a calibrated digital signal output over a single-bus interface.

Mounted on a convenience module breakout board, this sensor incorporates a built-in pull-up resistor and decoupling capacitor, allowing direct three-pin connection to microcontrollers such as Arduino, ESP32, ESP8266, and Raspberry Pi without requiring external passive components. It offers superior accuracy, wider measurement ranges, and higher resolution compared to basic DHT-11 sensors, making it an ideal choice for smart home automation, weather stations, HVAC monitoring, greenhouse climate control, and industrial data logging.

Key Features

• High-Precision Dual Sensing: Provides reliable measurements for both relative humidity and ambient temperature.
• Integrated Breakout Module: Built-in PCB with filtering capacitors and pull-up resistor simplifies wiring directly to three header pins.
• Calibrated Digital Output: Uses a single-bus digital signal transmission protocol to deliver pre-calibrated data over long distances.
• Wide Operating Range: Measures relative humidity from zero percent to one hundred percent and temperature from minus 40 degrees Celsius to plus 80 degrees Celsius.
• Low Power Consumption: Low power draw during active measurements and minimal standby power dissipation, making it suitable for battery-powered IoT applications.

Product Specifications

• Sensor Core: AM2302 / DHT-22 Capacitive Humidity Sensor & NTC Thermistor
• Operating Voltage Range: 3.3 Volts DC to 5.5 Volts DC
• Humidity Measurement Range: 0 percent to 100 percent Relative Humidity
• Humidity Accuracy: plus or minus 2 percent Relative Humidity (typical)
• Humidity Resolution: 0.1 percent Relative Humidity
• Temperature Measurement Range: minus 40 degrees Celsius to plus 80 degrees Celsius
• Temperature Accuracy: plus or minus 0.5 degrees Celsius (typical)
• Temperature Resolution: 0.1 degrees Celsius
• Sampling Rate / Sensing Interval: 0.5 Hertz (one reading every 2 seconds)
• Interface Protocol: Single-Bus Digital Signal
• Module Output Header: 3-Pin Male Header (DAT, VCC, GND)

Pinout and Module Interface Wiring

When looking at the front face of the red breakout board with the white mesh sensor housing at the top and header pins pointing to the right:

• Pin 1 (DAT / Data): Digital signal input/output line (connect to any digital microcontroller I/O pin).
• Pin 2 (VCC / Power): Positive power supply input (connect to 3.3 Volts DC or 5 Volts DC rail).
• Pin 3 (GND / Ground): Common system ground (connect to power / microcontroller ground line).

Sampling Rate and Sensor Handling Warning

The DHT-22 / AM2302 sensor has a maximum sampling frequency of 0.5 Hertz. Attempting to query or read data from the sensor faster than once every 2 seconds will lead to stale readings, checksum timing errors, or sensor self-heating, which distorts temperature readings. Avoid exposing the sensor element directly to volatile chemical vapors, condensing moisture, or extreme direct sunlight for extended periods.

NOTE: DHT-22 / AM2302 Sensor attached to this module is COPY (if you are looking for original Click Here)