Temperature and Humidity 🌡️

This is a Python Script for logging the humidity and the temperature on a Date Base (MySQL/MariaDB) from a DHT22 sensor.

Requirements

• DHT22 sensor -> https://www.sparkfun.com/datasheets/Sensors/Temperature/DHT22.pdf
• Raspberry PI
• Adafruit Python DHT Sensor Library -> https://github.com/adafruit/Adafruit_Python_DHT
• MariaDB/MySQL

Instalation

For this project we need to have the Adafruit library installed on our raspberry.

Create a new user on our SQL Database.

CREATE USER 'username'@'localhost' IDENTIFIED BY 'pass';

Create a new database.

CREATE DATABASE DHT22;

Permissions to our user for that database.

GRANT ALL PRIVILEGES ON *.* TO ‘username’@‘localhost’;

Create a new table where we save this information.

CREATE TABLE Reading (
    id INT AUTO_INCREMENT NOT NULL,
	date DATETIME NOT NULL,
	temperature DECIMAL(5,2) NOT NULL,
	humidity DECIMAL(5,2) NOT NULL,
	PRIMARY KEY (id)
	);

Now, if we execute the script, we have in our database the information of humidity and temperature, but...What happens if we want this to be done automatically? We could use the crontab file to automate this process!!!😎😎

crontab -e

And in this file we want to create a new line with our service. For example:

*/5 * * * *  /home/pi/Development/dht22-logger/logger-temp-hum.py &> /dev/null