1. Introduction
This manual provides detailed instructions for the WAVGAT series of digital temperature and humidity sensors, including models DHT11, DHT22, AM2301, AM2302, and AM2320. These sensors are designed for accurate and reliable environmental monitoring in various applications, from hobbyist projects with Arduino to industrial systems. They offer calibrated digital signal output, ensuring high reliability and long-term stability.
2. Specifications
2.1 General Product Properties
| Attribute | Value |
|---|---|
| Type | Humidity Sensor |
| Theory | Hall Sensor |
| Material | Polymer |
| Output | Analog Sensor (Note: Specific models provide digital output) |
| Use | Humidity Sensor |
| Brand Name | WAVGAT |
| Origin | Mainland China |
2.2 DHT11 / MW33 Sensor
The DHT11/MW33 digital temperature and humidity sensor is a composite sensor with a calibrated digital signal output. It utilizes dedicated digital module acquisition technology and temperature/humidity sensing technology for high reliability and long-term stability. It integrates a resistive wet sensor and an NTC temperature sensor with an 8-bit microcontroller. Key features include ultra-fast response, strong anti-interference, and cost-effectiveness. Each sensor is factory-calibrated, with coefficients stored in OTP memory for accurate signal processing. It features a single-wire serial interface for easy system integration, ultra-small size, and low power consumption, with signal transmission distances up to 20 meters. Available in a 4-pin single-row lead package.
Features:
- Relative humidity and temperature measurement
- All calibration, digital output
- Excellent long-term stability
- No extra parts required
- Extra long signal transmission distance
- Ultra low energy consumption
- 4-pin mounting
- Completely interchangeable
Parameters:
- Humidity measurement range: 0% to 99.9% (valid within 0°C-50°C range)
- Humidity measurement error: ±2%
- Temperature measurement range: -40°C ~ 80°C
- Temperature measurement error: ±0.5°C max ±1°C
- Resolution: 16 bits
- Sampling period: 2s
- Working voltage: 3V--5.5V
2.3 DHT22 Sensor
The DHT22 is a digital temperature and humidity sensor, similar to the DHT11 but offering higher accuracy and a wider measurement range. It also provides a calibrated digital signal output.
Parameters:
- Humidity measurement range: 0% to 99.9% (valid within 0°C-50°C range)
- Humidity measurement error: ±2%
- Temperature measurement range: -40°C ~ 80°C
- Temperature measurement error: ±0.5°C max ±1°C
- Resolution: 16 bits
- Sampling period: 2s
- Working voltage: 3V--5.5V
2.4 AM2320 Sensor
The AM2320 is a digital temperature and humidity sensor with a calibrated digital signal output. It uses a dedicated capture technology for high reliability and excellent long-term stability. The sensor includes a capacitive humidity sensing element and an integrated high-precision temperature measurement device, connected to a high-performance microprocessor. It offers excellent quality, fast response, strong anti-interference ability, and cost-effectiveness. The AM2320 communicates using a single bus or standard I2C, simplifying system integration. Its ultra-small size, low power consumption, and long signal transmission distance (up to 20 meters or more) make it suitable for various demanding applications. The I2C communication uses a standard sequence, allowing direct connection to an I2C bus without additional wiring. It provides humidity, temperature, and CRC check information directly via temperature-compensated output, eliminating the need for secondary calculations or temperature compensation for humidity.
Features:
- Ultra-small size
- Super cost-effective
- Ultra-low voltage operation
- Excellent long-term stability
- Standard I2C and single-bus output
- Power supply: DC 3.1~5.5V
Applications:
- HVAC systems
- Dehumidifiers
- Testing and inspection equipment
- Consumer goods
- Automotive applications
- Automation
- Data loggers
- Weather stations
- Home appliances
- Humidity control systems
- Medical devices
- Other relevant humidity measurement and control systems
2.5 AM2301 Sensor
The AM2301 Humidity Capacitance Digital Temperature and Humidity Sensor is a composite sensor with a calibrated digital signal output. It employs dedicated digital module acquisition technology and temperature/humidity sensing technology to ensure high reliability and excellent long-term stability. This product offers excellent quality, fast response, strong anti-interference ability, and cost-effectiveness. Each sensor is calibrated in a precision humidity calibration chamber, with calibration coefficients stored in OTP memory and used internally during signal processing. The sensor consists of a capacitive sensing element and an NTC temperature measuring element connected to a high-performance 8-bit microcontroller. Communication with the microprocessor is via a single bus, requiring only one line and transmitting 40 bits of data at a time (high first out). Its small size, low power consumption, and long communication distance make it suitable for demanding applications.
Parameters:
- Humidity measurement range: 0% to 99.9% (valid within 0°C-50°C range)
- Humidity measurement error: ±3%
- Temperature measurement range: -40°C ~ 80°C
- Temperature measurement error: ±0.3°C
- Resolution: 16 bits
- Sampling period: 2s
2.6 AM2302B Sensor
The AM2302B is a digital temperature and humidity sensor offering precise measurements and digital signal output via a single bus interface.
Parameters:
- Temperature range: -40~80°C
- Humidity range: 0~99.9%RH
- Temperature detection accuracy: ±0.5°C
- Humidity detection accuracy: ±2% RH
- Resolution: 0.1°C; 0.1% RH
- Sampling period: 2s
- Output signal: digital signal single bus
- Supply voltage: DC3.3~5.5V
2.7 Dimensions and Weights
| Name | Size (mm) | Weight (g) |
|---|---|---|
| AM2302 | 25x15 | 2.4 |
| DHT22 | 16x12 | 1.1 |
| DHT11 | 16x12 | 0.8 |
| AM2320 | 15x12 | 0.8 |
| Name | Length (mm) | Height (mm) | Weight (g) |
|---|---|---|---|
| AM2301 | 59.5 | 27 | 13.9 |
| AM2302 | 59.5 | 27 | 14.5 |
3. Setup and Connection
These sensors typically require three or four connections: VCC (power), GND (ground), and Data (for single-bus communication) or SDA/SCL (for I2C communication). A pull-up resistor on the data line is often recommended for single-bus sensors like DHT11/DHT22.
3.1 General Pinout
- VCC: Connect to 3.3V or 5V power supply (refer to specific sensor's working voltage).
- GND: Connect to ground.
- Data (or SDA/SCL): Connect to a digital I/O pin on your microcontroller. For I2C, SDA and SCL lines are used.
For single-bus sensors (e.g., DHT11, DHT22, AM2301, AM2302, AM2320 when used in single-bus mode), a 4.7kΩ to 10kΩ pull-up resistor is typically connected between the Data line and VCC.
3.2 Example Connection (Arduino)
While specific wiring diagrams are not provided, for Arduino users, the general connection involves:
- Connect the sensor's VCC pin to the Arduino's 5V or 3.3V pin.
- Connect the sensor's GND pin to the Arduino's GND pin.
- Connect the sensor's Data pin (or SDA/SCL for I2C models) to an appropriate digital pin on the Arduino.
- If using a single-bus sensor, add a pull-up resistor (e.g., 10kΩ) between the Data pin and VCC.
Refer to specific sensor libraries and examples for your chosen microcontroller platform for detailed wiring and code.
4. Operating Instructions
These sensors provide digital output, which requires a microcontroller (e.g., Arduino, ESP32, Raspberry Pi) to read and interpret the data. Libraries are commonly available for popular platforms to simplify data acquisition.
4.1 Data Acquisition (Single-Bus)
For sensors utilizing a single-bus interface (e.g., DHT11, DHT22, AM2301, AM2302, AM2320 in single-bus mode), the microcontroller initiates a data request, and the sensor responds with a 40-bit data packet containing humidity, temperature, and a checksum. The sampling period for these sensors is typically 2 seconds, meaning you should not request data more frequently than every 2 seconds to ensure accurate readings.
4.2 Data Acquisition (I2C)
For sensors supporting I2C communication (e.g., AM2320), the microcontroller acts as the master and communicates with the sensor (slave) using standard I2C protocols. This typically involves reading specific registers to obtain humidity and temperature data. I2C communication often allows for more robust data transfer and can support multiple sensors on the same bus.
4.3 Software Libraries
It is highly recommended to use existing software libraries for your microcontroller platform (e.g., Arduino DHT sensor library, Adafruit Unified Sensor Driver) to interface with these sensors. These libraries handle the complex timing and data parsing required for accurate readings.
5. Maintenance
These sensors are generally low-maintenance. Follow these guidelines to ensure optimal performance and longevity:
- Environmental Conditions: Avoid exposing the sensors to extreme conditions outside their specified operating ranges (temperature and humidity).
- Moisture and Condensation: Prevent prolonged exposure to high humidity or condensation, which can affect sensor accuracy and lifespan.
- Dust and Contaminants: Keep the sensor clean and free from dust, dirt, and chemical contaminants. Do not attempt to clean the sensing element directly with liquids or abrasive materials.
- Physical Damage: Handle the sensors with care to avoid physical damage to the pins or casing.
6. Troubleshooting
If you encounter issues with your sensor, consider the following troubleshooting steps:
- No Readings or Erratic Data:
- Check all wiring connections (VCC, GND, Data/SDA/SCL) for proper contact and polarity.
- Ensure the sensor is receiving the correct supply voltage (3.3V to 5.5V).
- Verify that a pull-up resistor is correctly installed on the Data line for single-bus sensors.
- Confirm that the correct software library is installed and configured for your specific sensor model and microcontroller.
- Check the sampling interval in your code; requesting data too frequently can lead to errors.
- Inaccurate Readings:
- Ensure the sensor is not exposed to direct sunlight, heat sources, or strong air currents, which can affect local temperature and humidity.
- Allow sufficient time for the sensor to stabilize after power-up or environmental changes.
- Verify that the sensor is operating within its specified temperature and humidity ranges.
- Dust or contaminants on the sensing element can cause inaccuracies; ensure the sensor is clean.
- Communication Errors:
- For I2C sensors, check for correct I2C address and bus initialization.
- Ensure no other devices are interfering with the communication bus.
7. Warranty and Support
7.1 Return Policy
This product is eligible for free returns within 90 days of purchase. Please refer to the seller's return policy for detailed terms and conditions.
7.2 Delivery Guarantee
We offer fast delivery services. In case of delayed delivery, a $1.00 coupon may be provided. Refunds are available if the package is lost or if items are damaged during transit. A full refund is also guaranteed if delivery is not completed within 60 days.
7.3 Security & Privacy
Your security and privacy are important to us. We ensure safe payments and do not share your personal details with any third parties without your consent. Your personal details are protected and kept safe and secure.
7.4 Disclaimer (California Proposition 65 Warning)
⚠ WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.