DHT11 Temperature and Humidity Sensor Module

DHT11 Temperature and Humidity Sensor Module is a fundamental, low-cost digital sensor designed for reliable environmental monitoring in hobbyist and entry-level industrial projects. This compact module accurately measures ambient air temperature and relative humidity, outputting the data via a single wire. Therefore, you can easily interface the DHT11 with any 8-bit or 32-bit microcontroller, including Arduino and Raspberry Pi. The module integrates the sensor components, a pull-up resistor, and necessary filtering onto a small PCB, simplifying setup and ensuring a clean signal. Consequently, this ready-to-use module offers an economical and straightforward solution for collecting essential climate data in smart home and weather station applications.

Key Features:

• Digital Output: The sensor provides pre-calibrated digital signals for both temperature and humidity, eliminating the need for complex analog-to-digital conversion circuits.
• Single Bus Communication: It utilizes a simple, proprietary 1-wire communication protocol, requiring only a single data pin on your microcontroller for full operation.
• Low Power Consumption: Operating with minimal current draw, thus making it ideal for battery-powered or energy-efficient embedded systems.
• Integrated Pull-up Resistor: The module version includes the necessary pull-up resistor on the data line, simplifying external wiring and component count.
• Excellent Long-Term Stability: The device provides reliable measurements over extended periods within its specified operating range.

Technical Specifications:

• Operating Voltage: 3.3 V to 5 V DC
• Humidity Measurement Range: 20% to 90% RH
• Humidity Accuracy: ±5% RH
• Temperature Measurement Range: 0°C to 50°C
• Temperature Accuracy: ±2°C
• Sampling Rate: Maximum 1 Hz (One reading every second)
• Quiescent Current: ≈ 50 μA

Mechanical Specifications:

• Sensor Housing: Plastic, White/Blue grid
• Module PCB Type: Small rectangular module with 3 or 4 pins (VCC, GND, Data, NC)
• Humidity Sensing Element: Capacitive type
• Temperature Sensing Element: NTC Thermistor type

Dimensions:

• Module PCB Size: ≈ 32 mm × 14 mm
• Sensor Body Dimensions: ≈ 15.5 mm × 12 mm × 5.5 mm
• Mounting Holes: Typically one M2 or M2.5 hole for easy chassis attachment
• Header Pin Pitch: 2.54 mm (Standard breadboard compatibility)

Pinout and Wiring:

• VCC (Power): Supply 3.3V or 5V DC power to this pin.
• Data (Signal): Connect this pin to a digital input/output pin on your microcontroller. This pin handles all communication.
• GND (Ground): Connect this pin to the common ground (0V) of your circuit.
• Wiring Note: Always ensure the Data line connects to a pin that supports the necessary timing for the DHT11’s unique 1-wire protocol. Furthermore, place the module close to the microcontroller to minimize signal degradation.

Datasheet Reference:

• Download DHT11 Sensor Datasheet

Commonly Used in:

• DIY Home Automation: Projects like smart thermostats, vent controls, and automated humidifiers use this sensor extensively.
• Educational Kits: Hence, it is a staple sensor in introductory Arduino and electronics educational kits due to its ease of use.
• Data Logging Systems: Affordable solutions for logging ambient temperature and humidity over time for non-critical analysis.

Applications:

• Basic Weather Stations: Building simple, localized weather monitoring devices.
• Terrarium and Incubator Monitoring: Tracking environmental conditions for plants, reptiles, or hatching eggs.
• Server Room/Closet Monitoring: Providing basic alerts for excessive heat or humidity levels.

Equivalent Models:

• DHT22 (AM2302): Offers significantly higher accuracy and a wider range, however, it comes at a slightly higher cost.
• SHTxx Series: Provides superior accuracy and calibration, typically using the I²C protocol.
• RHT01: Often used as a direct nomenclature equivalent for the DHT11, offering identical functionality.

Package Includes:

• 1 x DHT11 Temperature and Humidity Sensor Module (with PCB)