E-ink Meeting Room Schedule Display

Creating a wireless e-ink device provides an elegant solution for displaying schedules for meeting rooms or home offices. This project leverages high-visibility e-paper technology to create a low-power display that remains readable in various lighting conditions without the glare of traditional screens.

Beyond its primary function as a schedule tracker, the device is designed to be versatile. After office hours, it can automatically transition into a digital photo frame. In this mode, it displays images stored on a microSD card, making it an aesthetic addition to a home office environment when not in active use for meetings.

Hardware Platform

The system is built around the Soldered Inkplate 6, a powerful e-paper board powered by an ESP32 microcontroller. This board is specifically chosen for its integrated Wi-Fi capabilities and ease of use with the Arduino framework. To ensure portability and a clean aesthetic, the device is powered by a 3.7V Li-ion battery (3000mAh or greater) and housed in a custom 3D-printed case consisting of a front frame and a back cover.

For data connectivity and scheduling, the device uses Roombelt as its backend service. This integration allows the display to fetch real-time calendar information and update the e-ink screen accordingly.

Firmware and Development

The firmware is developed using PlatformIO within the Visual Studio Code environment. It utilizes the Arduino framework for ESP32, specifically targeting the esp32dev board configuration. The build process incorporates the Inkplate-Arduino-library to manage the display hardware, along with ArduinoJson for handling configuration data and a Crypto library for secure communications.

The project defines two primary build environments:

• Debug: Includes an exception decoder and higher log levels for development.
• Release: Optimized for performance with minimized logging.

Configuration and Setup

Connectivity settings are managed externally to the firmware, allowing for easy updates without recompiling the code. WiFi credentials and other settings are read from a config.json file stored on a FAT-formatted microSD card. The structure of this configuration is straightforward:

{
    "ssid": "WiFi network name",
    "password": "Wifi network password"
}

Assembly and Construction

The physical assembly involves two 3D-printed components. These parts are designed to be printed with supports at a 0.2 resolution and 20% infill. The assembly process is mechanical, requiring four M2*10 screws to secure the back cover to the front frame. Internally, the battery is secured to the back cover using double-sided tape, and the Inkplate board is seated within the front cover before the components are connected and screwed together.