DHT22 / AM2302 Digital Temperature and Humidity Sensor Module – Temperature & Humidity Monitor, Practical Replacement for SHT11/SHT15

Product Description

This module integrates the DHT22 (also known as AM2302) digital temperature and humidity sensor in a convenient package for microcontroller projects. It measures ambient temperature and relative humidity and outputs the data as a calibrated digital signal, eliminating the need for complex analog circuitry. The sensor is factory‑calibrated and communicates over a single digital data line using a simple proprietary protocol supported by many libraries (e.g., Arduino, ESP32, Raspberry Pi).

Compared with older SHT11/SHT15 sensors, the DHT22 offers similar practical performance for many hobbyist and light industrial applications at significantly lower cost and with very simple wiring. It is suitable for long‑term indoor monitoring where moderate sampling rates and good accuracy are sufficient.

Ideal Uses

• Home and office temperature and humidity monitoring.

• DIY weather stations and indoor climate dashboards.

• HVAC and ventilation control based on real‑time humidity and temperature.

• Greenhouse, terrarium, and storage environmental monitoring.

• IoT nodes that periodically report environmental conditions.

Compatibility

• Works with Arduino, ESP8266, ESP32, STM32, Raspberry Pi and most other microcontrollers or SBCs.
• Uses a single‑wire digital interface (data pin plus power and ground), widely supported by ready‑made libraries.
• Typically powered at 3.3 V or 5 V (check your specific module; many breakout boards are 3.3–5 V compatible).

Key Features

• Measures relative humidity and temperature with a digital calibrated output.
• Good accuracy for many applications:
• Humidity: typically within a few percent RH (e.g., around ±2–5%RH under normal conditions).
• Temperature: typically within around ±0.5–1 °C over much of its operating range.
• Single‑bus digital communication, reducing pin count and wiring complexity.
• Low sampling rate (commonly about once every 2 seconds), well suited to environmental monitoring.
• Factory‑calibrated with internal signal processing, minimizing the need for user‑side calibration.
• Plastic housing with vents for airflow, easy to mount in enclosures or panels.
• Technical Specs (Typical, Module‑Dependent)

Exact values depend on the specific DHT22/AM2302 module revision and manufacturer; always check your datasheet:

• Supply Voltage: commonly 3.3–6 V (many modules designed around 3.3–5 V).
• Current Consumption: low, suitable for low‑power and battery‑assisted applications.
• Humidity Range: approximately 0–100%RH (non‑condensing).
• Temperature Range: approximately −40 °C to +80 °C (practical accuracy best in a narrower band).
• Interface: single digital data line plus VCC and GND.
• Sampling Rate: about 0.5 Hz (one reading every 2 seconds).

What’s Included

• 1 × DHT22 / AM2302 Digital Temperature and Humidity Sensor Module (often mounted on a small PCB with pins).

Safety Note

• Intended primarily for indoor, non‑condensing environments; prolonged exposure to condensation, dust, or chemicals can degrade accuracy.
• Do not expose directly to water or corrosive atmospheres; use a ventilated but protective enclosure where necessary.
• Allow the sensor a brief stabilization period after power‑on before trusting readings, and avoid very rapid polling to ensure reliable measurements.