August 18, 2024

            Imagine having a sleek, modern vision board that not only keeps you organized but also fits seamlessly into your daily routine. That’s exactly what the ESP32 Vision Board offers—a minimalist, tech-savvy way to display your Google Calendar events using an ePaper screen.

            The ESP32 Vision Board is a custom device that connects to your Google Calendar and displays your upcoming events on an ePaper screen. The combination of the ESP32 microcontroller and ePaper technology makes this vision board both powerful and efficient.

            In this project, I utilized the ESP32 microcontroller to create a vision board that displays Google Calendar events on an ePaper screen by leveraging Wi-Fi connectivity and the Google Calendar API. The code begins by initializing the ESP32 and ePaper display, connecting to a Wi-Fi network, and synchronizing time using NTP servers. It then retrieves an OAuth2.0 access token using a stored refresh token to securely access Google Calendar. The microcontroller performs HTTP GET requests to fetch event data, which is parsed using ArduinoJson, and the events are rendered on the ePaper display in a structured format. I implemented a watchdog timer to ensure continuous operation, with the system periodically refreshing the display every 15 minutes to show the most current schedule, while handling time zone conversions to display events accurately.