Severin Teona - AAC2

teona.severin@stud.acs.upb.ro

The main idea behind this project is to have a smart video doorbell, whose camera is triggered by pressing a button. After the photo is taken, you get an e-mail (as a notification) to let you know somebody is at your door. In the e-mail you get a link to a simple HTTP server where you can see the photo. On the server there are also 2 buttons: one of them is used to open the door for the guest and greet him with a nice message using an LCD, and a button used just for sending a message that the owner is not home. If the first button is pressed, the door will also open. The main motivation for this project came actually from my parents: they have been asking me for the past year if I can build them a system like this, because at home, we don’t have any window facing the gate or the outside of the door. Furthermore, we don’t know if anyone enters our yard.

For this project, I used 2 ESP32 modules:

• ESP32 WROOM
• I2C HD44780 LCD
• SG90 servo
• ESP32-CAM module with SD Card
• CP2102 USB to Serial converter
• Button

This project contains 2 ESP32 modules, and is therefore divided in 2:

1. The first system is controlled by the ESP32-CAM module, which doesn’t have any power supply socket. Because of that, I used a CP2102 USB to Serial converter to power on the device and to also have access to its serial port. On this board I also connected a button on GPIO13 pin to trigger the photo being taken. With this module, I also had some problems: I managed to destroy the external flash memory chip and I had luck I managed to find someone to change it.
2. The second system uses the ESP32 WROOM module that controls a I2C LCD display that shows different messages and a SG90 servo motor that opens and closes the door. The servo motor is connected on the GPIO13 digital pin.

The hardware schema is presented below:

When it comes to software, I used Arduino IDE and the following libraries:

• ESP32-Wroom
  • WiFi.h - to connect to the internet
  • HTTPClient.h - to send HTTP requests
  • Arduino_JSON.h - to parse the response from the HTTP requests
  • Wire.h & LiquidTWI2. h - to communicate via I2C with the LCD display
• ESP32-Cam
  • esp_camera.h - the official library of the camera inside the module
  • WiFi.h - to connect to the internet
  • HTTPClient.h - to send HTTP requests
  • Arduino_JSON.h - to parse the response from the HTTP requests
  • FS.h & SD_MMC.h - to access the file system inside the SD card

The functionalities of both these modules are described in the following diagrams:

I have also created an Express JS server hosted on a Virtual Private Server (VPS) that listens to requests on port 8000. Also, I created a Vue JS application available on port 8080 that hosts the user interface of the server. The following picture is a screenshot of the UI:

We have a working system that can actually be used in real life situations. For now, the notifications are sent via e-mail using the IFTTT infrastructure, but it would be nice in the future to connect this little system with a mobile application. But for now, when the guest comes to you, he rings the camera trigger instead of the classic bell, his picture gets taken and sent to our private server, and the owner can choose what to do: to let the guest in or to display him a message.

To test this project, we used a 3D printed house as shown below:

The demo is available in the next link:

• Post images to cloud: https://randomnerdtutorials.com/esp32-cam-post-image-photo-server/
• Take photos and save to SD card: https://randomnerdtutorials.com/esp32-cam-take-photo-save-microsd-card/
• Useful WIfi library functions: https://randomnerdtutorials.com/esp32-useful-wi-fi-functions-arduino/
• LCD I2C library for HD44780: https://github.com/lincomatic/LiquidTWI2
• Componente:
  • https://www.cleste.ro
  • https://www.emag.ro