Volume not adjustable - Max98257 / ESP32

[DonRonito]

I'm currently running the following code, but can't seem to get the volume adjusted. No matter the value the speaker is playing 100%. What am I missing? :)

`/**

• @file streams-url_mp3-i2s.ino
• @author Phil Schatzmann
• @brief decode MP3 stream from url and output it on I2S
• @Version 0.1
• @Date 2021-96-25
• @copyright Copyright (c) 2021
  */

// install https://github.com/pschatzmann/arduino-libhelix.git

#include "AudioTools.h"
#include "AudioCodecs/CodecMP3Helix.h"

URLStream url("abcd","1234");
I2SStream i2s; // final output of decoded stream
VolumeStream volume(i2s);
EncodedAudioStream dec(&i2s, new MP3DecoderHelix()); // Decoding stream
StreamCopy copier(dec, url); // copy url to decoder

void setup(){
Serial.begin(115200);
AudioLogger::instance().begin(Serial, AudioLogger::Info);

// setup i2s
auto config = i2s.defaultConfig(TX_MODE);
// you could define e.g your pins and change other settings
config.pin_ws = 21;
config.pin_bck = 18;
config.pin_data = 19;
//config.mode = I2S_STD_FORMAT;
i2s.begin(config);

// set initial volume
volume.begin(config); // we need to provide the bits_per_sample and channels
volume.setVolume(0.3);

// setup I2S based on sampling rate provided by decoder
dec.setNotifyAudioChange(i2s);
dec.begin();

// mp3 radio
url.begin("http://stream.srg-ssr.ch/m/rsj/mp3_128","audio/mp3");

}

void loop(){
copier.copy();
}
`

[pschatzmann]

You send the output directly to i2s instead of to volume, so volume is not used anywhere!

[DonRonito]

Thank you. I edited to the following and it's now working :).

#include "AudioTools.h"
#include "AudioCodecs/CodecMP3Helix.h"

URLStream url("abcd","1234");
I2SStream i2s; // final output of decoded stream
VolumeStream volume(i2s);
EncodedAudioStream dec(&volume, new MP3DecoderHelix()); // Decoding stream
StreamCopy copier(dec, url); // copy url to decoder

void setup(){
Serial.begin(115200);
AudioLogger::instance().begin(Serial, AudioLogger::Info);

// setup i2s
auto config = i2s.defaultConfig(TX_MODE);
config.pin_ws = 21;
config.pin_bck = 18;
config.pin_data = 19;
i2s.begin(config);

// setup I2S based on sampling rate provided by decoder
dec.setNotifyAudioChange(i2s);
dec.begin();

// set initial volume
volume.begin(config); // we need to provide the bits_per_sample and channels
volume.setVolume(0.2);

// mp3 radio
url.begin("http://stream.srg-ssr.ch/m/rsj/mp3_128","audio/mp3");
}

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