DCC SOUNDCENTER 2.1
===================

Release 2.1 based on the tested 2.0 release.

Playback changes in 2.1:
- No MP3 starts automatically when SoundCenter powers up.
- The Play button on an individual MP3 plays only that file, then stops.
- The Play button at the top of a playlist plays the playlist sequence.
- Playlist playback remains confined to the selected playlist.

Main features:
- ESP32 based DCC controlled MP3 sound system
- DCC input on GPIO27 via 6N137
- Web based MP3 library, upload and playlists
- Permanent MP3 IDs and playlist references
- Metadata, search and sortable tables
- Play/Stop toggle directly from the library
- OLED status pages for network, playback and SD card
- SD card capacity, used/free space and file counts
- Three status LEDs: green WiFi, yellow DCC, blue Play
- Compact dark/gold DCC SOUNDCENTER logo
- OTA firmware update through ProjectUNION

Important:
- Keep partitions.csv in the same folder as the .ino file.
- If Arduino IDE reports a 1,310,720 byte maximum, choose a larger
  OTA-capable partition scheme under Tools > Partition Scheme.
- First upload after changing partition layout should be made by USB.

Hardware status LEDs:
- Green: WiFi connected
- Yellow: DCC signal / command activity
- Blue: MP3 playback active
