Meck/Audiobook Player Guide.md

Audiobook Player (Audio variant only)

Press P from the home screen to open the audiobook player. Place .m4b, .m4a, .mp3, or .wav files in /audiobooks/ on the SD card.

Key	Action
W / S	Scroll file list / Volume up-down
Enter	Select book / 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)

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.

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. MP3 format is recommended over M4B for best compatibility with the ESP32-audioI2S library.

SD Card Folder Structure

SD Card
├── audiobooks/
│   ├── .bookmarks/          (auto-created, stores resume positions)
│   │   ├── mybook.bmk
│   │   └── another.bmk
│   ├── mybook.m4b
│   ├── another.m4b
│   └── podcast.mp3
├── books/                   (existing — text reader)
│   └── ...
└── ...