The DHT22 Temperature and Humidity Sensor Module, also known as AM2302, is a high-accuracy digital sensor designed to measure ambient temperature and relative humidity. Compared to DHT11, it offers wider measurement ranges and better precision, making it ideal for weather stations, HVAC monitoring, smart agriculture, and IoT applications. The single-wire digital interface ensures reliable data transmission and easy integration with microcontrollers.
Core Sensor Specifications
• Sensor Type: Digital temperature and humidity sensor
• Sensor Model: DHT22 / AM2302
• Output Signal: Digital (single-wire data)
• Measurement Parameters: Temperature and relative humidity
Electrical & Interface
• Operating Voltage: 3.3 V – 6 V
• Communication Protocol: Single-wire digital interface
• Interface Pins: VCC, DATA, GND
• Sampling Rate: ~0.5 Hz (one reading every 2 seconds)
• Pull-up Resistor: Required on data line (typically 4.7 kΩ)
Performance Characteristics
• Temperature Range: −40 °C to +80 °C
• Temperature Accuracy: ±0.5 °C
• Humidity Range: 0–100 % RH
• Humidity Accuracy: ±2–5 % RH
• Factory calibrated for stable readings
Physical Characteristics
• Module Type: PCB-mounted sensor module
• Sensor Housing: Ventilated plastic enclosure
• Compact and lightweight design
• Suitable for indoor and semi-outdoor use (not waterproof)
Compatibility
• Arduino Uno / Nano / Mega
• ESP8266 / ESP32
• STM32, AVR, PIC microcontrollers
• Raspberry Pi (GPIO with library support)
Key Advantages
• Higher accuracy than DHT11
• Wide temperature and humidity range
• Digital output reduces noise and calibration effort
• Large ecosystem of libraries and examples
Technical Insights
• Each sensor is individually factory calibrated
• Long cable lengths supported with proper pull-up
• Slower sampling compared to some modern sensors
• Avoid direct exposure to water or condensation
Applications
• Weather monitoring systems
• Smart agriculture and greenhouse control
• HVAC and indoor climate monitoring
• IoT environmental sensing
• Home automation projects
Pro Tip
• Allow 1–2 seconds between readings
• Place sensor away from heat sources for accurate data
• Use proper pull-up resistor for stable communication
• Avoid direct sunlight and moisture exposure
Package Includes
• 1 × DHT22 Temperature and Humidity Sensor Module