Every one of us knows how significant it is to measure environmental temperature and humidity. But, the more significant aspect is to measure these factors with low cost and higher reliability and with great accuracy. DHT21/AM2301 is a sensor that has all these abilities.
An Overview
DHT21/Am2301 is a high-performance temperature and humidity sensor that provides accurate measurement is better for long transmission and consumes less power. The temperature measurement is relatively high with an accuracy of 0.5 degrees C in 0.1 degree C steps. It estimates the relative humidity accuracy of +/- 3%.
Hardware Overview
DHT21/Am2301 has a capacitive humidity sensing element that is already calibrated. The module has a high-performance 8-bit chip to provide the correct reading and ensure proper transmitting of the data. This temperature sensor has three wires including VCC and ground. And, hence there is only one digital pin that needs to be interfaced. The small size of the sensor makes it more convenient to use.
Interfacing with Microcontroller
To interface, you need to connect the red wire to the power supply within the range of 3V to 5V, the black wire to the system’s ground, and the yellow wire to your data input pin. If you want to interface multiple sensors for multiple readings, then each one must be interfaced with its data pin.
Features DHT21/AM2301
- 4-pin package.
- Ultra-low-power.
- No additional components.
- Excellent long-term stability.
- All calibration, digital output.
- Completely interchangeable.
- Long-distance signal transmission.
- Relative humidity and temperature measurement.
Specifications DHT21 AM2301
- Model: AM2301.
- Supply voltage: 3.3 ~ 5.2 V DC.
- Signal output form: Digital signal output.
- Temperature measurement range: -40 ~ +80 ºC.
- Temperature measurement precision: ± 0.5ºC.
- Humidity range: 10%~90%RH.
- Humidity measurement precision: ±3%RH.
Pinouts of DHT21 AM2301
| Pin color | Pin Name | Description |
| Red | Vcc | The power supply pin requires voltage from 3.5V to 5.5V |
| Yellow | Data | Output pin for both humidity and temperature through serial Data |
| Black | Ground | Connection of sensor to the system’s ground |
Applications
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 DHT21/AM2301 for highly accurate readings.
The Weather Station
Due to the reasonable cost of this temperature sensor, we can use this in practical weather stations projects that can depict the environmental temperature and humidity which may help in various industries.
