AM2302 (DHT22) Digital Temperature & Humidity Sensor Module | ATMOSFÆR ENGINEERING

High-precision capacitive humidity sensor with integrated temperature measurement and calibrated digital output. Features 1-wire communication protocol for easy connection using a single data pin. Factory-calibrated with onboard 8-bit microcontroller for signal processing. Provides ±0.5°C temperature and ±2% RH humidity accuracy with excellent long-term stability. Ideal for HVAC systems, weather stations, data loggers, and environmental monitoring applications.

Technical Specifications:

• Sensor Model: AM2302 (equivalent to DHT22)
• Interface: Single-wire digital (1-Wire protocol)
• Operating Voltage: 3.3V - 5V (5V recommended)
• Current Consumption: 1-1.5mA (measuring), 40-50µA (standby)
• Temperature Range: -40°C to +80°C
• Temperature Accuracy: ±0.5°C
• Humidity Range: 0% - 100% RH (20% - 90% RH optimal)
• Humidity Accuracy: ±2% RH (at 25°C)
• Resolution: 0.1°C (temperature), 0.1% RH (humidity)
• Sampling Rate: 0.5Hz (one reading every 2 seconds)
• Signal Transmission Distance: Up to 20 meters
• Response Time: <5 seconds (typical)
• Operating Temperature: -40°C to +80°C
• Module Dimensions: 40mm x 23mm
• Weight: 4g

Pin Configuration (3-pin):

• VCC/+: Power supply (3.3V - 5V)
• DATA/OUT: Digital data output (1-wire signal)
• GND/-: Ground

Features:

• Factory-calibrated (no user calibration required)
• Capacitive humidity sensor for high accuracy
• Integrated high-precision temperature sensor
• Onboard 8-bit microcontroller for signal processing
• Single-wire digital interface (simplified wiring)
• Ultra-low power consumption
• Fully interchangeable (standardized output)
• Excellent long-term stability
• Long signal transmission distance (20m+)
• Auto-calibration with stored coefficients

Applications:

• HVAC control systems
• Weather stations and meteorological monitoring
• Humidifiers and dehumidifiers
• Data loggers and environmental monitoring
• Greenhouse and agriculture automation
• Smart home climate control
• Consumer electronics (thermostats, air quality monitors)
• Automotive climate systems
• Test and inspection equipment
• Medical storage and transport
• Food storage monitoring
• Museum and archive preservation

Advantages:

• Higher accuracy than DHT11 (±2% vs ±5% RH)
• Wider temperature range than DHT11 (-40°C vs 0°C minimum)
• Better resolution (0.1 vs 1.0 for DHT11)
• Longer cable runs possible (20m vs 1m)
• More stable long-term performance

Important Notes:

• Minimum 2-second interval between readings (0.5Hz max sampling)
• Requires 4.7kΩ - 10kΩ pull-up resistor on data line (may be included on module)
• First reading after power-on may be unstable (discard first measurement)
• Avoid condensation on sensor (affects accuracy)
• Shield from direct sunlight for accurate temperature readings

Compatible with Arduino, ESP32, Raspberry Pi, STM32, and any microcontroller with digital GPIO. Libraries available: DHT sensor library (Arduino), Adafruit_DHT (Python for Raspberry Pi).