If you are a beginner, you can learn about Arduino - Wifi here.
In this tutorial, I am going to show you how to detect the door-opening event and send a notification via Gmail using Arduino Uno. I made this tutorial for beginners! It is really easy!
Let's get started!
Magnetic sensor I used includes two parts: sensor and magnet. When two parts are in proximity, the output pin of the sensor is HIGH, otherwise the output pin is LOW. Taking advantage of this feature, I installed one part of the sensor on the door leaf and the other on the door frame. By checking state of the output pin, we can detect when door is opened and then make an alert or send a notification.
In this project, when an event occurs, a notification is sent via Gmail.