dht11-module

![Snipaste_2020-02-25_12-29-03.png] ### Product introduction: 1. DHT11 digital temperature and humidity sensor is a temperature and humidity composite sensor with calibrated digital signal output. It applies dedicated digital module acquisition technology and temperature and humidity sensing technology to ensure that the product has extremely high reliability and excellent long-term stability. The sensor includes a capacitive humidity sensing element and an NTC temperature measuring element, and is connected to a high-performance 8-bit microcontroller. 2. Application scope HVAC, dehumidifier, agriculture, cold chain warehousing, testing and inspection equipment, consumer goods, automobiles, automatic control, data loggers, weather stations, home appliances, humidity regulators, medical, and other related humidity detection and control. 3. Product highlights include low cost, long-term stability, relative humidity and temperature measurement, excellent quality, ultra-fast response, strong anti-interference ability, ultra-long signal transmission distance, digital signal output, and precise calibration. ![Snipaste_2020-02-25_12-27-51.png] Pin description 1. VDD power supply 3.3~5.5V DC2, DATA serial data, single bus 3. NC empty pin 4, GND grounded, power supply negative ### * *Typical application circuit:** **![Snipaste_2020-02-25_12-31-26.png] ** The typical application circuit of the connection between the microprocessor and DHT11 is as shown in the figure above. After DATA is pulled up, it is connected to the I of the microprocessor. /O port is connected. 1. In the typical application circuit, it is recommended to use a 4.7K pull-up resistor when the length of the connection line is shorter than 5m. When the length is longer than 5m, reduce the resistance of the pull-up resistor according to the actual situation. 2. When using 3.3V voltage power supply, the connecting wire should be as short as possible. If the connecting wire is too long, it will cause insufficient power supply to the sensor and cause measurement deviation. 3. The temperature and humidity value read each time is the result of the last measurement. To obtain real-time data, it is necessary to read the sensor twice continuously. However, it is not recommended to read the sensor multiple times in a row. The interval between reading the sensor should be more than 2 seconds. Get accurate data. 4. If the power supply part fluctuates, it will affect the temperature. If the ripple of a switching power supply is too large, the temperature will jump.