Looking for a very basic Example: mp3 from SD-Card to I2S with custom pin-config

[FerFemNemBem]

Hi,
I'm new to C & Arduino but in most cases I can find examples that work for me. Now I'm struggeling with a very simple thing:
I want to play a single mp3-file from an SD-Card to I2S. Sounds simple (maybe it is) but I have no Idea how to configure the pins and define the file(name). The maybe most related example "player-sd-i2s". But this has a "startFilePath" and an "extension" only, not a filename itself defined. Further - where can I define my pin-config for I2S and the SPI? The following pseudocode-snippets hopefully explain what I want toi do and what I'm missing:

#include <Arduino.h>
#include <FS.h>
#include "AudioTools.h"
#include "AudioCodecs/CodecMP3Helix.h"

#define USE_HELIX 
#define USE_SDFAT

SPIClass spiSD(HSPI);
#define SD_CS 5

File mp3File;

#define LRCLK 25
#define BCLK 26
#define DIN 33

AudioSourceSdFat source(startFilePath, ext);
I2SStream i2s; **=> where to config my i2s pins?**
MP3DecoderHelix decoder;
AudioPlayer player(source, i2s, decoder);

void setup() 
{
  **=> Where to define the SPI-Pins for the "AudioSourceSdFat" like the spiSD.begin(...) method?**
  //spiSD.begin(14, 12, 13, SD_CS);
  //SD.begin(SD_CS, spiSD))
  //mp3File = SD.open("/Sound/test.mp3");
  ...
  player.begin();
}

void loop()
{
  player.copy();
}

Thank you!

Best regards,
FFNB

[pschatzmann]

I suggest that you take the example streams-sd_mp3-i2s.

The AudioPlayer is for playing many files, therefore you indicate just a directory. In addition please notice that this class is using the https://github.com/greiman/SdFat library!

For the pins I suggest that you read the chapter about External-DAC

I also recommend that you have a look at the class documentation where you find all the classes with their methods and the pubic attributes

[FerFemNemBem]

@pschatzmann

You nailed it! This is exactly what I was looking for!
Thank you!

Best regards,
Jan