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Fabian Schlenz fa208858d9 Webinterface: Added an overlay to display when the websocket isn't connected. 1 year ago
bin Added empty (for now) update.manifest. 1 year ago
include Debug and Trace modes can now be (de)activated via API commands and are persisted across reboots. 1 year ago
lib Initial commit. 2 years ago
src Webinterface: Added an overlay to display when the websocket isn't connected. 1 year ago
test Initial commit. 2 years ago
.gitignore Add config.h to .gitignore. 1 year ago
.travis.yml Initial commit. 2 years ago Better deploy script. 1 year ago Debug and Trace modes can now be (de)activated via API commands and are persisted across reboots. 1 year ago Added FTP server and automatic version generation. 2 years ago Fix calculation error. 1 year ago
partitions.csv Moved index.html from SPIFFS to program memory. Removed dependencies to SPIFFS. Also, we can use a different partition scheme with much more program space instead of reserving some of it for SPIFFS. 1 year ago
platformio.ini Disabled the custom partitioning stuff because the ESP32 entered a boot loop after flashing it. So we are back at ~85% memory used... 1 year ago


What you need

Please note: This list is a "things I used", neither "these are the best things for this stuff" nor "you can only use these things". But please be aware that using other stuff may lead to you having to make more or less easy modifications.

Prizes are more or less the cheapest I could find on Aliexpress.

What?  For what?  Price (approx)
ESP-32-WROOM-32D  Controlling everything   4€
WS1053B on a PCB with SD card slot  Play the MP3 files; provide an SD card slot   5€
MFRC522  RFID reader 1€
5V Amplifier(s) (e.g. 2x PAM-8302)  Single-channel Amplifier   2€
Speaker(s) matching your amp (e.g. 2pcs 4 Ohm 5W)  Enabling you to hear the sounds   4€
RFID tags (ISO14443A) - e.g. 10 cards  You can also get Keyfobs or stickers   4€
4 buttons Prev/Next track, Volume up/down   1€

You'all also need an SD card, some breadboard(s), jumper cables and a soldering iron. Also, some kind of box for the finished player.

How to connect

Schematics coming soon...ish...

How to install

Format your SD card with FAT32 and put files on it: Every album has to go into its own folder in the root of the SD card. Folders and files should not contain special characters (meaning stuff like äöüß). Spaces and dashes an alike are okay. Put the SD card into the SD card slot.

Copy include/config.sample.h to include/config.h. Modify it to at least contain the correct login details for your WiFi.

The code then should compile in PlatformIO without errors. Upload it to your ESP32. After that, upload static files using PlatformIO's task "Upload file system image".

The serial console in PlatformIO should give you more or less useful messages about what's going on. There will also be a line saying "WiFi connected. IP address:" when the connection to your WiFi succeeded.

In your browser, enter "" (using the IP address) from above. From there you can define mappings between RFID tag IDs and folders on the SD card.


Via webinterface

To create a new mapping between an RFID tag and an folder, you can use the web interface. Click the button with the cogs icon. After putting your rfid tag on the reader (and possibly removing it again), its ID will be shown in the dialog. Click the button with the arrows behind the ID to start the mapping mode.

The dialog showing all folders with media files will be shown. Click the button with the arrows behind the correct folder, to create the mapping.


Mapping are stored on the SD card in the file /_mapping.txt. Every mapping goes on its own line. Lines should be separated by \n (Unix- style line endings); the last line should also end with a newline.

Format of a line is <RFID id>=<folder>. RFID id is the UID of an RFID tag, expressed as 8 lowercase characters with leading 0 (if necessary). Folder is the foldername to play; starting with a slash and ending without one.

A valid _mapping.txt could look like this:

1a2b3c4d=/Christmas Music Vol. 17
003aab7f=/Let it go
b691a22c=/Frozen Audiobook
22cb6ae9=/Let it go

(Yes, more than one tag can map to a folder.)

Technical details


Device Port Connected to
VS1053 CS 16
VS1053 MISO 19
VS1053 MOSI 23
VS1053 SCK 18
VS1053 XCS 4
VS1053 XDCS 2
VS1053 DREQ 15
RC522 SDA 17
RC522 SCK 18
RC522 MOSI 23
RC522 MISO 19

Buttons pull to GND if pushed -> Internal Pull-Up needed!

RFID tags

The mapping of rfid tags to files uses the ID of the tag. A file called _mapping.txt in the root folder of the SD card defines the mappings between RFID tag ids and folders to play.

The easiest way to create this file is to use the mapping functionality of the webinterface.

Special modes

You can also save data on the tags to further manipulate the system. Position of the data is irrelevant, the whole tag will be searched.

Using [random] will play the files in a random order. [random:2] will randomize everything except the first 2 files. This can be useful for having the favorite song of your kids playing, but after that getting a bit of randomness.

Using [lock] will turn this key into a key for the locking mode. Scanning the tag enables locking mode. The next album started will keep running until the end. Removing the tag will be deactivated, as are the buttons for prev and next track. You can disable locking mode by again scanning the lock tag again.

[advent] is used for christmas time. An album with this tag will only play in December. On December 1st, only track 1 will play. On December 2nd, track 2 followed by track 1. On December 3rd, tracks 3, 1 and 2. From December 24th on, track 24 followed by tracks 1-23. So your kid will get the "daily track" first, followed by all previous tags in the right order.


You can send commands to ESMP3 using three different ways:

  • Through a websocket connection to ws://<IP>/ws.
  • Through the serial console using an USB cable.
  • Via HTTP POST request to http://<IP>/cmd, having the command in the variable cmd.

Supported commands are:

Command Action
play <PATH> Starts playing the given path. Path may be a path on the
sd card or a http(s) URL of a webstream (direct links to mp3/4/ogg streams,
PLS files, M3U files or podcast XML feeds are supported).
play Continues playing the previously played thing.
stop Stops playing.
volume=<X> Sets the volume to X (0-255).
track_prev Starts the previous track, if available.
track_next Starts the next track, if available.
track=<X> Starts playing track no. X of the currently playing album.
reset_vs1053 Resets the VS1053 audio chip.
reboot Reboots ESMP3.
add_mapping=<ID>=<PATH> Adds a mapping between RFID card and path
. See play for valid path formats.
update Runs an update check.
`debug=<0 1>`
`trace=<0 1>`