Papyrix User Guide

Welcome to the Papyrix firmware. This guide outlines the hardware controls, navigation, and reading features of the device.

1. Hardware Overview

The device utilises the standard buttons on the Xtink X4 in the same layout:

Button Layout

Bottom Edge: Back, Confirm, Left, Right
Right Side: Power, Volume Up, Volume Down

2. Power & Startup

Power On / Off

To turn the device on or off, press and hold the Power button for half a second. In Settings you can configure the power button to trigger on a short press instead of a long one.

First Launch

Upon turning the device on for the first time, you will be placed on the Home screen.

Note: On subsequent restarts, the firmware will automatically reopen the last book you were reading (configurable via Startup Behavior in Settings).

3. Screens

3.1 Home Screen

With cover:

Without cover:

Empty:

The Home Screen displays the title "Papyrix" at the top with a battery indicator in the top-right corner.

Book Display

The center of the screen shows the cover of the currently open book, with the book title and author displayed below it.

No book open: Displays "No book open"

Bottom Bar

Four buttons at the bottom of the screen:

Read — Continue reading the current book
Files — Browse and select books from the SD card
Sync — File transfer over WiFi or Calibre wireless sync
Settings — Device settings

Navigation:

Use Left/Right or Volume Up/Down to move between buttons
Press Confirm to select

3.2 Book Selection (Files)

The Files screen acts as a folder and file browser.

Navigate List: Use Left (or Volume Up), or Right (or Volume Down) to move the selection cursor up and down through folders and books.
Open Selection: Press Confirm to open a folder or read a selected book.
Delete Item: Press the Right button to delete the selected file or folder. A confirmation dialog will appear; select Yes to confirm deletion or No to cancel.

Note: EPUB (.epub), FB2 (.fb2), HTML (.html, .htm), XTC (.xtc, .xtch), Markdown (.md, .markdown), and plain text (.txt, .text) file formats are supported. EPUB 2 and EPUB 3 formats are fully supported. FB2 files support metadata, TOC navigation, and text formatting (no inline images). HTML files render as standalone documents with formatting. Markdown files render with basic formatting (headers, bold, italic, lists). The device supports both FAT32 and exFAT formatted SD cards.

Note: The following folders are automatically hidden from the file browser:

System Volume Information, LOST.DIR, $RECYCLE.BIN — OS system folders

config — Papyrix configuration files

XTCache — XTC format cache

sleep — Custom sleep screen images

.papyrix — Internal cache (dot-prefix hidden by default)

Note: Each folder can display up to 1000 items. Organize large libraries into subfolders if you exceed this limit.

Note: You cannot delete the currently open book. Close the book first before deleting it.

3.3 Reading Screen

Test:

Images:

Arabic (RTL):

Landscape:

See 4. Reading Mode below for more information.

3.4 File Transfer (Sync)

File transfer is accessible from the Home screen by pressing the Left button (or from the file browser, select Sync). This allows you to upload new e-books to the device over WiFi or connect to Calibre.

When you enter the screen, you'll be prompted to choose a network mode:

Join Network: Connect to an existing WiFi network. You'll see a list of available networks and can enter passwords as needed. Previously saved networks will connect automatically.
Create Hotspot: The X4 creates its own WiFi network that you can connect to directly from your computer or phone.

Once connected, your X4 will start hosting a web server. See the webserver docs for more information on how to connect and upload files.

Note: When you exit File Transfer, the device will automatically restart to reclaim memory used by WiFi.

3.5 Settings

The Settings screen is organized into four categories:

Reader

Reading and display settings:

Theme (default: light)
- Select from available themes (light, dark, or custom themes from SD card)
- Themes control colors, layout, and fonts
- See Customization Guide for creating custom themes
Font Size (default: Small)
- Options: XSmall (12pt), Small (14pt), Normal (16pt), Large (18pt)
- Text size for reading
Text Layout (default: Standard)
- Options: Compact, Standard, Large
- Controls first-line indentation and paragraph spacing:
  - Compact: No indent, no extra spacing (dense text)
  - Standard: Normal indent (em-space), small spacing between paragraphs
  - Large: Large indent, full line spacing between paragraphs
Line Spacing (default: Normal)
- Options: Compact, Normal, Relaxed, Large
- Controls vertical spacing between lines within paragraphs:
  - Compact: Tighter line spacing (0.85×)
  - Normal: Standard line spacing (0.95×)
  - Relaxed: More space between lines (1.10×)
  - Large: Maximum line spacing (1.20×)
- Adjusting line spacing can improve readability for different fonts and preferences
Text Anti-Aliasing (default: OFF)
- Enable grayscale text rendering for smoother font edges
- Works with both builtin fonts and custom fonts converted with --2bit
- Disable for faster page turns and to eliminate the brief "thick text" flash during transitions
Paragraph Alignment (default: Justified)
- Options: Justified, Left, Center, Right
- Text alignment for paragraphs (headers remain centered)
Hyphenation (default: ON)
- Break long words at soft hyphen positions embedded in EPUB content
- Words too wide for the line are automatically split with character-level hyphenation
- Reduces large gaps in justified text and prevents words from overflowing
Show Images (default: ON)
- Display inline images within EPUB content and book covers
- Disable for faster page rendering (images show "[Image]" placeholder)
Status Bar (default: Full)
- Options: None, No Progress, Full
- Controls the reading screen status bar display
- Full: Shows battery, book title, and page number (e.g., "5 / 12")
- No Progress: Shows battery and book title only
- None: Hides the status bar entirely for maximum reading area
- Note: The total page count for a chapter appears only after the chapter is fully cached. While reading through a chapter for the first time, only the current page number is shown until all pages have been rendered. Overall book completion percentage is not available due to memory constraints on the device.
Reading Orientation (default: Portrait)
- Options: Portrait, Landscape CW, Inverted, Landscape CCW
- Screen orientation for reading

Device

Power and device behavior settings:

Auto Sleep Timeout (default: 10 min)
- Options: 5 min, 10 min, 15 min, 30 min, Never
- Time of inactivity before the device automatically sleeps
Sleep Screen (default: Dark)
- Options: Dark, Light, Custom, Cover
- Which image to display when the device sleeps
Startup Behavior (default: Last Document)
- Options: Last Document, Home
- Last Document: Resume reading the last opened book on startup
- Home: Always start at the Home screen
Short Power Button (default: Ignore)
- Options: Ignore, Sleep, Page Turn
- Ignore: Short press does nothing (long press for sleep)
- Sleep: Short press puts device to sleep
- Page Turn: Short press turns to next page while reading (convenient for one-handed reading)
Pages Per Refresh (default: 15)
- Options: 1, 5, 10, 15, 30
- Number of pages to turn before performing a full e-paper refresh (clears ghosting)
Sunlight Fading Fix (default: OFF)
- Powers down the display after each page refresh
- Prevents screen fading in bright sunlight (UV exposure causes the SSD1677 driver IC to fade to white)
- Adds ~100-200ms overhead per page turn
- Recommended for white X4 devices used outdoors
Front Buttons (default: B/C/L/R)
- Options: B/C/L/R, L/R/B/C
- B/C/L/R: Back, Confirm, Left, Right (default layout)
- L/R/B/C: Left, Right, Back, Confirm (swapped layout)
Side Buttons (default: Prev/Next)
- Options: Prev/Next, Next/Prev
- Prev/Next: Volume Up = previous page, Volume Down = next page
- Next/Prev: Volume Up = next page, Volume Down = previous page

Cleanup

Maintenance actions for the device:

Clear Book Cache — Delete all cached book data and reading progress
Clear Device Storage — Erase internal flash storage (requires restart)
Factory Reset — Erase ALL data (caches, settings, WiFi credentials, fonts) and restart device

System Info

View device information: firmware version, uptime, WiFi status, MAC address, free memory, internal disk usage, SD card usage

3.6 Calibre Wireless

Calibre Wireless allows you to send books directly from Calibre (the popular ebook management software) to your Papyrix Reader over WiFi. This is the fastest way to transfer books if you already use Calibre.

Prerequisites

Calibre installed on your computer
Both devices on the same WiFi network

Connecting to Calibre

From the Home screen, press Left to access Sync, then select Calibre Wireless
Connect to your WiFi network (same as your computer)
The device will show its IP address and port (e.g., 192.168.1.42:9090)
The screen displays "Waiting for Calibre..."

In Calibre Desktop

Click Connect/Share in the toolbar
Select Start wireless device connection
Calibre will automatically discover your Papyrix Reader
Your device appears as "Papyrix Reader" (or your custom name)

Sending Books

Once connected:

Right-click any book in Calibre
Select Send to device > Send to main memory
The book transfers wirelessly to your reader's /Books/ folder

Bidirectional Sync

Calibre can also:

See your library - View books already on your device
Delete books - Remove books from the device remotely

Configuration

Customize settings via /config/calibre.ini on your SD card:

[Settings]
device_name = Papyrix Reader
password =

device_name: How your device appears in Calibre
password: Optional password (must match Calibre's wireless device password)

For detailed instructions, see the Calibre Wireless Guide.

Note: When you exit Calibre Wireless, the device will automatically restart to reclaim memory used by WiFi.

3.7 Sleep Screen

You can customize the sleep screen by placing custom images in specific locations on the SD card:

Single Image: Place a file named sleep.bmp in the root directory.
Multiple Images: Create a sleep directory in the root of the SD card and place any number of .bmp images inside. If images are found in this directory, they will take priority over the sleep.bmp file, and one will be randomly selected each time the device sleeps.

Note

You'll need to set the Sleep Screen setting to Custom in order to use these images.

Image Parameters

Resolution: 480 × 800 pixels (portrait mode)
Color depth: 8-bit grayscale or 24-bit color
Format: BMP, uncompressed (BI_RGB)
Display levels: 4 grayscale (black, dark gray, light gray, white)

Tip

Use 8-bit grayscale for best results - it's widely supported by image editors
Larger images will be automatically scaled down while preserving aspect ratio
All color images are converted to 4-level grayscale on the e-ink display

Tip

The Cover sleep screen option displays the cover of the currently open book when the device sleeps.

Cover mode:

4. Reading Mode

Once you have opened a book, the button layout changes to facilitate reading.

Page Turning

Previous Page: Press Left or Volume Up
Next Page: Press Right or Volume Down
Power Button: When Short Power Button is set to Page Turn in Settings, pressing the power button also turns to the next page (convenient for one-handed reading)

Chapter Navigation

Next Chapter: Press and hold the Right (or Volume Down) button briefly, then release.
Previous Chapter: Press and hold the Left (or Volume Up) button briefly, then release.

System Navigation

Return to Home: Press Back to close the book and return to the Book Selection screen.
Reader Menu: Press Confirm to open the Reader Menu (access chapters and bookmarks).

4.1 Reader Menu

Press Confirm while reading to open the Reader Menu. The menu provides two options:

Chapters — Open the Table of Contents / Chapter Selection screen
Bookmarks — Open the Bookmarks overlay for the current book

Use Left/Right to highlight a menu item and Confirm to select. Press Back to close the menu and return to reading.

4.2 Bookmarks

The Bookmarks overlay lists all saved bookmarks for the current book, sorted by page position.

Controls

Back — Close the bookmarks overlay
Go — Jump to the selected bookmark's page
Add — Bookmark the current page
Del — Remove the selected bookmark

Use Left/Right (or Volume Up/Down) to move the selection cursor through the bookmark list.

Details

Each book supports up to 20 bookmarks. Adding a bookmark when the limit is reached is silently ignored.
Duplicate bookmarks at the same position are not allowed.
Bookmarks are persisted to the SD card and survive device restarts.
Each book has its own independent set of bookmarks.

5. Chapter Selection Screen