ESP32 electronic guestbook: a unique wedding gift

Recently, Sebastian Staacks, a physicist and development engineer from Germany, created a unique electronic guestbook for his brother's wedding. The guestbook is developed based on the ESP32 Wi-Fi module. All wedding guests can log in to a simple web interface through their mobile phones, enter text messages and upload pictures. Affected by the COVID-19 epidemic, some friends cannot be present, but they can express their greetings and blessings to the couple remotely through this guestbook.
How this electronic guestbook works is very simple. Visitors only need to enter the obtained URL in their mobile browser to open an editor for filling in their name and information. The editor also supports functions such as selecting fonts and drawing decorations. In addition, the preview of the message will be displayed directly on the Web interface for users to view, just like it will be displayed on the electronic guestbook screen. Finally, as long as the message passes the security check, it can be submitted successfully. The heart of

the hardware
guestbook is the Waveshare 7.5-inch e-paper display, which is similar in size to most regular e-book readers. This black-and-white display has a matte finish that maintains good readability in bright light. Although its resolution is only 800x480, it is sufficient for this device. The best thing about Waveshare monitors is that they are primarily aimed at makers, so they come with a driver board that connects to a Raspberry Pi or Arduino and provide resources and examples to drive the monitor.
The LEDs for the guestbook were taken by Sebastian from a short piece of WS2801 LED strip. He only used 6 LEDs to ensure that the total current consumption of the project did not exceed 500 mA. This way, the guestbook can be run on any USB port. On the day of the wedding, Sebastian installed a mobile power supply in the guest book, which can theoretically provide power for 20 hours. If this guestbook is later used as a desktop decoration, it can also be powered by a wired charger.
The ESP32-WROOM-32 module serves as the "brain" of the guestbook and also plays an important role in the project. Based on this module, Sebastian was able to use Wi-Fi at the wedding to query the network server for new messages and store them in the SPI Flash File System (SPIFFS) of the ESP32-WROOM-32. The screen driver and LED of the guestbook can be directly connected to the GPIO port of the ESP32 without the need for other additional electronic devices.