In this, we are going to interface the DHT11 temperature sensor to Raspberry Pi. Here DHT11 sensor measures the temperature and humidity in the air surrounded by the sensor and is displayed on the serial monitor.

DHT11 is a commonly digital temperature sensor used to measure the humidity and temperature and we can also interface this sensor easily with any microcontroller such as Arduino, RPi (Raspberry Pi), etc. For measuring temperature and humidity DHT11 sensor is available in the module as well as in sensor.

We can use a DHT11 sensor in many applications such as

• HVAC (Heating, Ventilation, Air Conditioning)

• Home appliances

• Weather stations etc.

Raspberry Pi is a low cost, small size computer that plugs into a computer monitor, and uses a keyboard and mouse. It is capable device that enables us to explore computing and to learn how to program in languages like scratch and python. It is capable of doing what we expect a computer to do. It has many interfaces like HDMI, multiple USB, Ethernet, onboard Wi-Fi and Bluetooth, GPIOs, USB powered etc. also supports to LINUX, Python to make easy to build applications. Raspberry is available in different versions the latest version of Raspberry Pi is Pi3+ Model and the Updated version is Pi4 model. In Raspberry Pi 3B+ Model this model is having 64-bit quad core (processor) running at 1.4GHz, dual band 2.4GHz, 5GHz wireless LAN, Bluetooth 4.2/BLE, faster Ethernet, and PoE (power on Ethernet) capability with separate PoE HAT. Raspberry Pi3 Mode B+ maintains the same footprint as raspberry Pi2 and Raspberry Pi3 Model B.

1. Vin: Two 5v pins and two 3v3 pins used for providing power supply, where processor works on 3.3v.

2. Ground: Having 8 ground Pins which are un-configurable.

3. GPIO: There are 26 input-output pins which will be used as input or output based on programming.

4. PWM: In software PWM are available for all pins but in hardware PWM is available for GPIO12, GPIO13, GPIO18, and GPIO19.

5. 2 SPI bus: These pins are used for SPI communication the pins which are used for SPI is MISO, MOSI, SCLK, CE0, and CE1

6. I2C: These pins are used for I2C communication in which DATA and CLOCK pins are used for sending data to and from the SDA connection, with the speed controlled with SCL pin and ID-SE, ID-SC are reserved for ID EEPROM.

7. TX and RX: This pins are used for UART communication.

DHT11 consists of three pins they are:

• Vcc (power supply) 3.3v to 5v

• Data

• Ground

import Adafruit_DHT

Sensor=Adafruit_DHT.DHT11

Pin=4

While True:

Humidity, temperature= Adafruit_DHT.read(sensor,pin)

if humidity is not None and temperature is not None:

Print(‘temp={0:0.1f}*c Humidity={1:0.1f}%’. Format (temperature,humidity))

else:

print(‘failed to get reading’)