Python Script for a Digital Frame

A Python script that displays images on a screen in a continuous slideshow. It supports multiple image sources: a WebDAV server (e.g. Nextcloud), a local folder, or a USB stick. Images are automatically rotated based on their EXIF orientation. It runs on a Raspberry Pi Zero 2W using Pygame to write directly to the screen buffer without requiring a desktop environment.

Attention: The script is a bit rough and makes many assumptions. For my use case it works, but there is no guarantee. Use with caution.

Requirements

• Pygame - to display the images
• Pillow - for EXIF-based image rotation
• webdavclient3 - to download images from a WebDAV server (only needed for the webdav source)

The concrete packages and versions are listed in the requirements.txt.

Installation

• Install the Python dependencies, e.g. using requirements.txt and pip
• Install the OS dependencies:
  • Pygame uses SDL2 to write images into the buffer
  • SDL2 needs to be installed, e.g. for Debian: sudo apt install libsdl2-2.0-0 libsdl2-ttf-2.0-0

Usage

python digital_frame.py [path/to/config.json]

The config path defaults to config.json in the current working directory if not provided.

Configuration

The image source and display settings are configured via a JSON file. The source field selects which image source to use.

WebDAV (e.g. Nextcloud)

{
    "source": "webdav",
    "webdav_hostname": "https://your-nextcloud/remote.php/dav/files/user/diashow",
    "webdav_login":    "user",
    "webdav_password": "password",
    "webdav_timeout":  60,
    "online_check_address": "live-address-to-check",
    "image_duration": 30,
    "width": 1024,
    "height": 600
}

Local Folder

{
    "source": "local_folder",
    "image_folder": "/path/to/images",
    "image_duration": 30,
    "width": 1024,
    "height": 600
}

USB Stick

{
    "source": "usb_mount",
    "usb_device": "/dev/sda1",
    "usb_mount_point": "/mnt/stick",
    "image_duration": 30,
    "width": 1024,
    "height": 600
}

Configuration Fields

Field	Description
source	Image source: webdav, local_folder, or usb_mount
webdav_hostname	Full URL to the WebDAV folder
webdav_login	WebDAV username
webdav_password	WebDAV password
webdav_timeout	Timeout in seconds for the WebDAV connection
online_check_address	URL polled until reachable before starting (optional)
image_folder	Path to the local image folder (local_folder source)
usb_device	Device path of the USB stick, e.g. /dev/sda1 (usb_mount source)
usb_mount_point	Mount point for the USB stick (usb_mount source)
image_duration	Time in seconds each image is shown
width	Screen width in pixels
height	Screen height in pixels