Humidity and temperature measurement are significant, not just to make humans aware of different weather. But, also it’s essential for many industries. For example, temperature and humidity measurements help the agricultural to grow healthy plants.
An Overview about DHT11 Sensor
DHT11 is an inexpensive yet reliable temperature and humidity sensor. It enables an estimation of the environmental conditions of humidity and temperature. One can interface the sensor with any microcontroller to get the weather reading of the environment.
Internal Structure
The internal structure of the sensor comprises the thermistor and a humidity sensing element. The thermistor generally changes its resistance with the change of temperature. On the other side, the humidity component has two electrodes that have a substrate between them. As the resistance gets changed, the conductivity of this substrate also gets changed. And, that’s how the sensor works.
Working Principle
The DHT11 sensor has a thermal resistance. Practically, it’s a resistance that changes with temperature. Hence, the term Negative resistance coefficient (NTC) is associated with this. NTC means that resistance decreases with the increment of the temperature. Also, the sensor includes the small PCB inside which estimates the analog signal, converts the analog signals into digital, and gives the digital output.
Features and Specifications of DHT11 Sensor
Features
- The sensor ensures high reliability
- Full range temperature compensated
- Relative humidity and temperature measurement
- Calibrated digital signal
- Outstanding long-term stability
- Extra components not needed
- Long transmission distance
- Low power consumption
- 4 pins packaged and fully interchangeable
- fast response
- Anti-interference ability
- Cost Effective
Specifications
- Operating Voltage: 3.5V to 5.5V
- Operating current: 0.3mA (measuring) 60uA (standby)
- Output: Serial data
- Temperature Range: 0°C to 50°C
- Humidity Range: 20% to 90%
- Resolution: Temperature and Humidity both are 16 bit
- Accuracy: ±1°C and ±1%
Pinouts of DHT11 Sensor
| Pin number | Pin Name | Description |
| 1 | Vcc | The power supply pin requires voltage from 3.5V to 5.5V |
| 2 | Data | Output pin for both humidity and temperature through serial Data |
| 3 | NC | No connection Pin. This pin is not for connecting. |
| 4 | Ground | Connection of sensor to the system’s ground |
Applications of DHT11 Sensor
IoT Environmental Monitoring
An environmental monitoring process is a system that monitors or controls the quality of the environment. One can also develop an IoT temperature monitoring system using a temperature sensor. Hence, this system also employs humidity and temperature sensors like DHT11.
Weather Station
Because of the low cost of this temperature sensor, this can be used in cheap yet effective weather stations that can depict the environmental temperature and humidity which may help in various industries.
Climate Control
Climate control is a system for regulating the temperature. Therefore, the DHT11 temperature and humidity sensor may help to get the environmental readings to work accordingly. For example, the microcontroller gets the temperature and humidity sensor from the sensor, If the temperature exceeds an upper or lower threshold, the system would act accordingly.
