Raspberry pi with DHT11

The  DHT11  is a commonly used  Temperature and humidity sensor that  comes with a dedicated NTC to measure temperature and an 8-bit microco...

The DHT11 is a commonly used Temperature and humidity sensor that comes with a dedicated NTC to measure temperature and an 8-bit microcontroller to output the values of temperature and humidity as serial data.

 

DHT11 Pinout Configuration

No:	Pin Name	Description
For DHT11 Sensor
1	Vcc	Power supply 3.5V to 5.5V
2	Data	Outputs both Temperature and Humidity through serial Data
3	NC	No Connection and hence not used
4	Ground	Connected to the ground of the circuit
For DHT11 Sensor module
1	Vcc	Power supply 3.5V to 5.5V
2	Data	Outputs both Temperature and Humidity through serial Data
3	Ground	Connected to the ground of the circuit

DHT11 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

To be able to easily communicate with some sensors, CircuitPython has been developed .So, before installing the specific DHT-library, we have to do dome work:

Open a terminal window and write followinf commands:

sudo apt update

sudo pat full-upgrade

sudo apt install python3-pip

sudo pip3 install --upgrade setuptools

it will take 10 min in raspberry pi 3B

Then install and run a script developed by Adafruit:

sudo pip3 install --upgrade adafruit-python-shell

wget https://raw.githubusercontent.com/adafruit/Raspberry-Pi-Installer-Scripts/master/raspi-blinka.py

sudo python3 raspi-blinka.py

Install the CircuitPython-DHT Library

Open a terminal window and write following commands

pip3 install adafruit-circuitpython-dht

sudo apt-get install libgpiod2

To enable dht11.py script run automatic copy temperature.service file inside /etc/systemd/system of raspberry pi

Enjoy!!

Output will be on log file inside /var/log of raspberry pi 

All python code , service file and bash code are available on my github 
https://github.com/sushildurlov/DHT11-with-raspberry-pi