Paper-Display

This project aims to transform the LilyGo EPD47, a development board based on an ESP32 with an e-paper display, into a display that renders images server side. The goal is for the device to send a request to a server that responds with an image and a sleep time. The device will then enter deep sleep mode for the specified duration before repeating the process.

The clients request also includes an image_id parameter, which allows the server to react on the currently displayed image. This enables the server either send a partial image or no image at all. The schema for the server response is outlined in Schema.md.

Getting Started

To get this code running, you first need to create a configuration file. Please rename copy the file epaper_config.example.h into epaper_config.h and fill in the required values.

This project uses platform.io. Download the Tool for your platform or IDE of choice. Then you can run:

pio run build

To build and upload the code to your device of choice.

SSL certificates

The device does not have any root certificates installed. Therefore, it is not able to verify a server's certificate. You can generate a certificate bundle using the following script:

python3 tools/gen_crt_bundle.py

The generated file will be added automatically to your device during the next upload.

Troubleshooting

If you are unable to patch or access the device due to its deep sleep state, you can hold down the STR_IO0 button while connecting a USB-C cable. This will force the device into flash mode, allowing you to make necessary changes and resume normal operation.

Examples

An example implementation of a server providing images in the required schema can be found in the paper-image-server repository.

Acknowledgements

The code for this project is heavily inspired by the following sources:

• LilyGo EPD47 GitHub Page
• LilyGo EPD-4-7 OWM Weather Display GitHub Page