3.0 KiB
Audiobook Player (Audio variant only)
Press P from the home screen to open the audiobook player.
Place .mp3, .m4b, .m4a, or .wav files in /audiobooks/ on the SD card.
Files can be organised into subfolders (e.g. by author) — use Enter to
browse into folders and .. (up) to go back.
| Key | Action |
|---|---|
| W / S | Scroll file list / Volume up-down |
| Enter | Select book or folder / Play-Pause |
| A | Seek back 30 seconds |
| D | Seek forward 30 seconds |
| [ | Previous chapter (M4B only) |
| ] | Next chapter (M4B only) |
| Q | Leave player (audio continues) / Close book (when paused) / Exit (from file list) |
Recommended Format
MP3 is the recommended format. M4B/M4A files are supported but currently have playback issues with the ESP32-audioI2S library — some files may fail to decode or produce silence. MP3 files play reliably and are the safest choice.
MP3 files should be encoded at a 44100 Hz sample rate. Lower sample rates (e.g. 22050 Hz) can cause distortion or playback failure due to ESP32-S3 I2S hardware limitations.
Bookmarks are saved automatically every 30 seconds during playback and when you stop or exit. Reopening a book resumes from your last position.
Cover art from M4B files is displayed as dithered monochrome on the e-ink screen, along with title, author, and chapter information.
Metadata caching — the first time you open the audiobook player, it reads title and author tags from each file (which can take a few seconds with many files). This metadata is cached to the SD card so subsequent visits load near-instantly. If you add or remove files the cache updates automatically.
Background Playback
Audio continues playing when you leave the audiobook player screen. Press Q while audio is playing to return to the home screen — a >> indicator will appear in the status bar next to the battery icon to show that audio is active in the background. Press P at any time to return to the player screen and resume control.
If you pause or stop playback first and then press Q, the book is closed and you're returned to the file list instead.
Audio Hardware
The audiobook player uses the PCM5102A I2S DAC on the audio variant of the T-Deck Pro (I2S pins: BCLK=7, DOUT=8, LRC=9). Audio is output via the 3.5mm headphone jack.
Note: The audiobook player is not available on the 4G modem variant due to I2S pin conflicts.
SD Card Folder Structure
SD Card
├── audiobooks/
│ ├── .bookmarks/ (auto-created, stores resume positions)
│ │ ├── mybook.bmk
│ │ └── another.bmk
│ ├── .metacache (auto-created, speeds up file list loading)
│ ├── Ann Leckie/
│ │ ├── Ancillary Justice.mp3
│ │ └── Ancillary Sword.mp3
│ ├── Iain M. Banks/
│ │ └── The Algebraist.mp3
│ ├── mybook.mp3
│ └── podcast.mp3
├── books/ (existing — text reader)
│ └── ...
└── ...