Electronics

DHT11 Temperature And Humidity Sensor Module With DIP Red LED

AED 15.75

1

Description

The DHT11 Module sensor is a cutting-edge device that accurately measures temperature and humidity. This remarkable sensor provides a precise digital output, directly proportional to the temperature and humidity levels it detects. With its pre-calibrated digital output, you can trust its readings to be highly accurate and reliable for convenient operation and visual feedback, the board includes a DIP red power LED. This LED serves as an indicator, allowing you to instantly know whether the board is powered on.

 

Package Includes:

  • 1 x DHT11 Temperature And Humidity Sensor Module With DIP Red LED
  • 3 x Female-to-female jumper wire

 

Features:

  • Relative Humidity and Temperature Measurement: The module accurately measures both relative humidity and temperature, providing valuable data for environmental monitoring.
  • Full Range Temperature Compensation: The module incorporates full range temperature compensation, ensuring precise temperature measurements across various operating conditions.
  • Calibrated Digital Signal: The module provides a calibrated digital output, eliminating the need for additional calibration processes and simplifying integration with other devices.
  • DIP Red Power LED: The module includes a DIP red power LED, which serves as a visual indicator, giving a clear indication of the power status of the module.
  • Long-Term Stability: With its high-quality construction and design, the module offers long-term stability, ensuring consistent and accurate readings over extended periods.
  • Low Power Consumption: The module is designed with low power consumption in mind, making it suitable for energy-efficient applications and minimizing the impact on overall system power requirements.
  • Ready-to-Go Mode and MCU Connectivity: The module is available in a ready-to-go mode, enabling easy integration with microcontroller units (MCUs) and other devices. It can be directly connected to the MCU without the need for complex setup or configuration.
  • Screw Hole for Fixation: The module features a screw hole that allows for secure fixation, ensuring stability when installed in various applications.

 

Description:

The DHT11 is a highly popular and reliable digital sensor widely utilized for monitoring temperature and humidity levels in various environments. It incorporates a capacitive humidity sensor and a thermistor-based temperature sensor, allowing accurate and precise measurements. With a humidity sensing range of 20% to 90% and an accuracy of 5%, the DHT11 sensor provides reliable data on relative humidity. For temperature measurements, it covers a range of 0 to 50 degrees Celsius with an accuracy of 2°C. These specifications ensure that you receive accurate and dependable readings for both humidity and temperature. Operating at a sample time of approximately 2 seconds, the DHT11 sensor promptly captures environmental changes, providing real-time data for monitoring applications. The communication between the DHT11 sensor and a microcontroller unit (MCU) is achieved through a digital pin using a one-wire interface protocol. This digital output simplifies the integration process and eliminates the need for analog inputs, streamlining the connection to the MCU. The DHT11 sensor comes pre-calibrated, offering a convenient and ready-to-use solution. Its digital output is already calibrated, saving time and effort during setup. To ensure optimal performance, the module features a unique capacitive sensor element for monitoring relative humidity, alongside a negative temperature coefficient (NTC) thermistor for temperature measurement. This combination guarantees high dependability and long-term stability in data accuracy. For seamless integration, the module includes a pull-up resistor and an additional filter capacitor specifically designed to support the DHT11 sensor. These components enhance the module's performance and make it ready for immediate use, facilitating a direct connection to the MCU.

 

Principle of Work:

The DHT11 sensor, whether in a standalone sensor or module form, operates in a similar manner. The sensor consists of four pins, with only three pins utilized, while the module typically has three pins. The primary distinction lies in the presence of a filtering capacitor and a pull-up resistor, which are included within the module but may need to be externally added for the sensor. To initiate the data collection process, the microcontroller unit (MCU) sends a trigger signal to the DHT11 sensor. This signal prompts the sensor to transition from a low-power consumption state to an active mode, where it begins sensing and collecting data. Once the sensor has completed its data collection, it sends a feedback signal back to the MCU. The collected data consists of 40 bits of information, which are transmitted to the MCU. It's important to note that the 40-bit data is already acquired by the sensor before the trigger signal is sent by the MCU. Each trigger signal results in a single set of 40-bit data being transmitted from the sensor to the MCU. If further data is required, a new trigger signal needs to be sent to initiate another round of data collection. For communication between the MCU and the DHT11 sensor, a single-bus data transmission method is employed. This means that data is transmitted using a single data line, simplifying the communication process.

 

Pinout of the Board:

Note: The sensor will burn down if you connect VCC and GND in the wrong Wiring.

 Connect 3.3-5.5V in the VCC (+) pin and ground on the GND(-) pin. Connect the middle pin which is a digital output of the sensor module with a microcontroller digital I/O pin. 

1

Vcc

Power supply 3.5V to 5.5V

2

Data

Outputs both Temperature and Humidity through serial Data

3

Ground

Connected to the ground of the circuit


Applications:

  1. Home Automation: The module can be used in home automation systems to monitor and control indoor climate conditions. It helps regulate temperature and humidity levels for optimal comfort and energy efficiency.
  2. Weather Monitoring: The DHT11 module is suitable for weather monitoring stations and devices. It provides real-time temperature and humidity data, enabling accurate weather forecasting and analysis.
  3. HVAC Systems: Heating, ventilation, and air conditioning (HVAC) systems benefit from the DHT11 module's ability to measure temperature and humidity. It assists in maintaining optimal indoor air quality and controlling climate conditions.
  4. Agriculture: The module is useful in agricultural applications such as greenhouse monitoring and precision farming. It helps farmers monitor and control the temperature and humidity levels within agricultural environments to optimize crop growth.
  5. Data Logging: The DHT11 module can be integrated into data logging systems to record temperature and humidity variations over time. This information can be used for analysis, research, and quality control purposes.
  6. Industrial Monitoring: Industrial processes often require precise control of temperature and humidity. The DHT11 module can be employed in industrial monitoring systems to ensure proper environmental conditions for manufacturing processes and equipment.
  7. IoT Devices: With its low power consumption and compact form factor, the DHT11 module is well-suited for Internet of Things (IoT) devices. It can be integrated into smart home devices, wearable gadgets, and other IoT applications that require environmental sensing.
  8. Laboratory and Scientific Research: The module finds utility in laboratories and scientific research settings. It enables researchers to monitor and control temperature and humidity levels in controlled environments and experiments.

 

Circuit:

To retrieve temperature readings from the DHT11 sensor, we will establish a connection between the sensor and the Arduino board. First, we will connect the VCC pin of the DHT11 module to the 5V pin on the Arduino board to provide power. Next, we will connect the GND pin of the module to the GND pin on the Arduino board to establish a common ground. Finally, we will connect the OUT pin of the module to the A0 analog input pin on the Arduino board. Once the connections are in place, we can proceed to read the temperature data from the DHT11 sensor using the Arduino. The Arduino will then display the temperature readings on the serial monitor, allowing us to monitor and analyze the data in real time.

 

Library: 

  1. Download the DHT library: You can obtain the library by clicking on the following link: DHT Library.
  2. Open Arduino IDE: Launch the Arduino IDE on your computer.
  3. Access the library manager: In the Arduino IDE menu, navigate to "Sketch" and select "Include Library" followed by "Add .Zip Library."
  4. Locate and select the downloaded library: Browse your computer to find the downloaded DHT library (master.zip) and select it.
  5. Install the library: The Arduino IDE will install the library automatically, and you will receive a confirmation message once the installation is complete.

 

Code:

This code is for reading and displaying temperature and humidity data from a DHT11 sensor using an Arduino board:

#include "dht.h"

#define dht_pin A0     // Analog Pin A0 of Arduino is connected to DHT11 out pin 
dht DHT;

void setup()
{
  Serial.begin(9600);
  delay(500);
  Serial.println("DHT11 Humidity & temperature Sensor\n\n");
  delay(1000);
}
 
void loop()
{
    DHT.read11(dht_pin);
    
    float humidity = DHT.humidity;
    float temperature = DHT.temperature;
    
    Serial.print("Humidity = ");
    Serial.print(humidity);
    Serial.print("%    ");
    Serial.print("Temperature = ");
    Serial.print(temperature); 
    Serial.println(" C");
    
    delay(5000); // Reduce Time for Quick Reply 
}

  • The line #include "dht.h" includes the necessary library for the DHT sensor.
  • #define dht_pin A0 defines a constant dht_pin and sets it to A0, indicating that the DHT11 sensor is connected to analog pin A0 on the Arduino board.
  • dht DHT; declares an object DHT of the dht class.
  • In the setup() function:

    • Serial.begin(9600); initializes the serial communication at a baud rate of 9600.
    • delay(500); introduces a delay of 500 milliseconds.
    • Serial.println("DHT11 Humidity & temperature Sensor\n\n"); prints a message to the serial monitor indicating the start of the program.
    • delay(1000); introduces a delay of 1000 milliseconds.
  • In the loop() function:

    • DHT.read11(dht_pin); reads the temperature and humidity values from the DHT11 sensor connected to the dht_pin.
    • float humidity = DHT.humidity; and float temperature = DHT.temperature; store the humidity and temperature values respectively into float variables.
    • Serial.print() statements are used to print the humidity and temperature values to the serial monitor.
    • delay(5000); introduces a delay of 5000 milliseconds, allowing a brief pause between each reading.

 

Technical Details:

  • Input Voltage: 3.3V ~ 5V
  • Current Supply: 0.5 ~ 2.5mA
  • Output Type: Digital
  • Humidity Range: 20% ~ 90% RH
  • Humidity Accuracy: ±5% RH
  • Humidity Resolution: 1% RH
  • Temperature measurement range: 0°C ~ 50°C
  • Temperature Accuracy: ±2°C
  • Temperature Resolution: 1℃
  • Power indicator: Red LED
  • Pin Number: 3 Pin
  • Size: 32mm x 14mm

 

Resources:

Tutorial1

 

Comparisons:

DHT11 is a popular temperature and humidity-based digital sensor. There is an upgraded version of the DHT11 temperature and humidity sensor available, which is the DHT22 Sensor with higher sensing ranges if you want to use the more basic sensor in your beginner project or something easy to code we recommend starting with LM35. When comparing the DHT11 module, DHT22 sensor, and LM35 sensor, there are several factors to consider:

  1. Temperature and Humidity Sensing Range:

    • DHT11: The DHT11 sensor has a temperature sensing range of 0 to 50 degrees Celsius with an accuracy of ±2°C. Its relative humidity sensing range is 20% to 90% with an accuracy of ±5%.
    • DHT22: The DHT22 sensor has a wider temperature sensing range of -40 to 80 degrees Celsius with an accuracy of ±0.5°C. Its relative humidity sensing range is 0% to 100% with an accuracy of ±2-5%.
    • LM35: The LM35 sensor has a temperature sensing range of -55 to 150 degrees Celsius with an accuracy of ±0.5°C.
  2. Sensor Type and Output:

    • DHT11 and DHT22: Both the DHT11 and DHT22 sensors are digital sensors, providing temperature and humidity readings as digital outputs that need to be read by a microcontroller or similar device.
    • LM35: The LM35 sensor is an analog sensor, providing temperature readings as an analog voltage output that can be directly measured by an analog input of a microcontroller or read using an analog-to-digital converter (ADC).
  3. Power Consumption:

    • DHT11 and DHT22: Both the DHT11 and DHT22 sensors have relatively low power consumption, making them suitable for battery-powered applications.
    • LM35: The LM35 sensor also has low power consumption, allowing it to be used in energy-efficient systems.
  4. Long-Term Stability:

    • DHT11 and DHT22: Both the DHT11 and DHT22 sensors are designed to offer long-term stability in temperature and humidity measurements.
    • LM35: The LM35 sensor provides stable and accurate temperature measurements over time.
  5. Price:

    • DHT11: The DHT11 sensor is generally more affordable compared to the DHT22 and LM35 sensors.
    • DHT22: The DHT22 sensor is slightly more expensive than the DHT11 but offers a wider sensing range and higher accuracy.
    • LM35: The LM35 sensor falls within a similar price range as the DHT22 and provides precise temperature measurements.
  6. Applications:

    • DHT11 and DHT22: Both sensors are suitable for various applications such as home automation, weather monitoring, HVAC systems, agriculture, data logging, and IoT devices.
    • LM35: The LM35 sensor is commonly used in industrial applications, HVAC systems, temperature-controlled systems, and laboratory equipment.

The choice between the DHT11 module, DHT22 sensor, and LM35 sensor depends on specific requirements such as sensing range, accuracy, sensor type, power consumption, stability, and budget.