Node.js library for easily creating an ePaper display on a Raspberry Pi using HTML and Javascript.

ePaper.js can be used as:

• A command line application for single step rendering of a URL onto an ePaper display
• A library that can interface ePaper displays with custom Node.js applications

Features include:

• Supports multiple ePaper Displays
• High performance, native c++ hardware access
• Multiple color modes: black / white, grayscale, black / white / red
• Dithering for black / white images

ejs <command> [options] <deviceType>

For example, the following command will update the Waveshare 7.5" v2 screen with the contents of http://localhost:8080 every 10 minutes.

ejs refresh rpi-7in5-v2 "http://localhost:8080"

For available devices types, see supported hardware. The different commands and suggested workflows are described below.

Display: display a single rendition of a URL

ejs display [options] <deviceType> <url>

Refresh: continuously update and display the URL

ejs refresh [options] <deviceType> <url>

Clear: clear the display

ejs clear [options] <deviceType>

Self-Hosting

• Create a web app and store it on your Raspberry Pi
• Host the web app with http-server
• Run ePaper.js with ejs refresh <deviceType> "http://localhost:8080" (or whatever port you configure http-server to run on)

Cloud Hosting

• Create a web app and host it on a service like GitHub Pages or Netlify
• Run ePaper.js with ejs refresh <deviceType> "<URL of your app>"

Running As a Daemon
There are several methods of automatically launching ePaper.js on startup and restarting in case of failures

• Run with pm2
• Create a systemd service

See the examples directory

• weather-station: This creates an example weather station display
• color-test: Used to test the various color modes
• 4gray: A demonstration of the 4gray capabilities
• dithering: A demonstration of the dithering feature

The following versions are the recommended versions that using during development and testing. Other versions may work, but are not officially supported.

• Node.js: 16 LTS
• Raspberry Pi OS: Bullseye 32 / 64bit
• Chromium: 104.0.5112.105

Enable SPI

sudo raspi-config
# Choose Interfacing Options -> SPI -> Yes  to enable SPI interface
sudo reboot

Install Node The official recommendation by Node.js is to install Node with a package manager. This helps ensure you'll have the latest LTS version and the proper permissions to install global packages. ePaper.js recommends using nvm

Raspberry Pi 2, 3, 4 Zero 2:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
source ~/.bashrc
nvm install 16

Raspberry Pi 1, Zero:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
source ~/.bashrc
NVM_NODEJS_ORG_MIRROR=https://unofficial-builds.nodejs.org/download/release
nvm install 16

Install Dependencies

sudo apt-get update
sudo apt-get install -y build-essential chromium-browser

Install ePaper.js
Globally install the @epaperjs/cli command line app and the appropriate package for your screen (See supported hardware). For example, to install ePaper.js for the Waveshare 7.5" V2 Screen:

npm install --global @epaperjs/cli @epaperjs/rpi-7in5-v2

It's easy to extend ePaper.js to support additional Waveshare devices. Displays from other manufacturers should be possible to support as well, as long as there is a C / C++ driver available.

If you would like to request support for another display, please open an issue with the title 'Add support for <Device Make \ Model>'. If you're a developer and have extended support yourself, put up a pull request!