Humidity and Temperature Sensor DHT11

The module shown in your image is indeed a DHT11, a basic, ultra-low-cost digital temperature and humidity sensor. Because it outputs a digital signal, it is highly straightforward to interface with microcontrollers, requiring no analog input pins.

The sensor contains a chip that does analog-to-digital conversion and spits out a digital signal with the temperature and humidity. The specific version in your image is mounted on a breakout board, which conveniently includes a surface-mounted pull-up resistor (labeled "103" for 10kΩ) on the data line.

Technical Specifications

Here are the standard operating parameters for the DHT11:

Pinout Description

While the bare DHT11 sensor has 4 pins, the breakout board module in your image simplifies this to 3 pins:

• S (Signal / Data): Outputs the digital temperature and humidity data. This connects to any digital pin on your microcontroller.

• Middle Pin (VCC): Provides power to the sensor. Connects to 3.3V or 5V.

• Right Pin (GND): Completes the circuit. Connects to the ground (GND) pin on your board.

Key Characteristics

• Ease of Use: It relies on a single-bus digital signal, and libraries for interpreting its specific communication timing are universally available for almost all standard microcontroller platforms.

• Limitations: The DHT11 is strictly for basic data logging or environments where precise, rapid changes do not need to be measured. You can only query it for new data once every second, and it cannot read negative temperatures or extreme humidity levels.