ESP32 Wroom 32E A2DP sink + sound reactive Led Stripe

[cocowayco]

Hi,

I am streaming audio via Bluetooth to an ESP 32 Wroom Board and via I2S to MAX98357.
I hooked up an 8 Leds Stripe (WS2812B) to a GPIO.
Do you know how can I make the Leds react to the audio like a VU meter?

[pschatzmann]

Just use the functionality of the AudioTools library.
Use a MultiOutput to send the output to an I2SStream and a VolumeMeter. From the latter you can pick up the volume.
Further info can be found into the Wiki...

[cocowayco]

ok you are saying to send the same signal to both the output chip and the Led stripe?
I can't find an audio meter function

[pschatzmann]

I's not audio meter but VolumeMeter!
And yes, a MultiOutput sends the output to any audio sink that has been added.

[Ives-Heymans]

Hi Phil, I hope you can give some guidance here, I used this simple example and tried numerous of ordering and assigning but as soon as I add the VolumeMeter to the MultiOutput (in any order) the output does not give any music anymore. Commenting out the multiOut.add(vuMeter); brings the output back. Any suggestions on what I am missing ? Thank you, have a nice day, Ives #include "AudioTools.h" #include "BluetoothA2DPSink.h" // Define streams AudioInfo input_stream_info(44100, 2, 16); // Define Outputs I2SStream I2Sout; VolumeMeter vuMeter; MultiOutput multiOut; // Link BT Input - send to multiOut ? BluetoothA2DPSink a2dp_sink(multiOut); void setup() { Serial.begin(115200); delay(200); // Set vuOutput vuMeter.begin(input_stream_info); // Setup I2S Output auto cfg = I2Sout.defaultConfig(); cfg.copyFrom(input_stream_info); cfg.pin_bck = 22; cfg.pin_ws = 25; cfg.pin_data = 21; I2Sout.begin(cfg); // Add Outputs //multiOut.add(vuMeter); multiOut.add(I2Sout); multiOut.begin(input_stream_info); // start a2dp_sink.set_auto_reconnect(true, 100); a2dp_sink.start("BTPlayer"); } void loop() { Serial.print(vuMeter.volumePercent(0)); Serial.print("\n"); Serial.print(vuMeter.volumePercent(1)); Serial.print("\n"); }

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________________________________ From: Phil Schatzmann Sent: Wednesday, April 23, 2025 3:29 PM To: pschatzmann/ESP32-A2DP Cc: Subscribed Subject: Re: [pschatzmann/ESP32-A2DP] ESP32 Wroom 32E A2DP sink + sound reactive Led Stripe (Discussion #703) I's not audio meter but VolumeMeter<https://pschatzmann.github.io/arduino-audio-tools/classaudio__tools_1_1_volume_meter.html>! And yes, a MultiOutput<https://pschatzmann.github.io/arduino-audio-tools/classaudio__tools_1_1_multi_output.html> sends the output to any audio sink that has been added. — Reply to this email directly, view it on GitHub<#703 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/A2TVDDEGS4KFOV3AJCHEQCT226IURAVCNFSM6AAAAAB3WEBJSSVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEOJSGMYTKNA>. You are receiving this because you are subscribed to this thread.

[pschatzmann]

Hmm, I will need to look into this.

However, I just realized that the VolumeMeter can also be used in a chain, so the MultiOutput is not needed.
Can you try this instead:

I2SStream I2Sout;
VolumeMeter vuMeter(i2Sout);
BluetoothA2DPSink a2dp_sink(vuMeter);

[pschatzmann]

I also recommend to add some delay() to the loop...

[cocowayco]

this is how I did it. Maybe can help
With this lines:
volumeL *= 10; // Increase volume sensitivity by a factor of 10
volumeR *= 10; // Increase volume sensitivity by a factor of 10

you control the "strenght" of the signal, aka how many Led will lit, so you might need to change it according to your input signal

#include "AudioTools.h"
#include "BluetoothA2DPSink.h"
#include "FastLED.h"

// ==== LED Setup ====
#define NUM_LEDS 8
#define DATA_PIN_LEFT 4 // GPIO4 - Left channel
#define DATA_PIN_RIGHT 2 // GPIO2 - Right channel

CRGB ledsLeft[NUM_LEDS];
CRGB ledsRight[NUM_LEDS];

// ==== Audio Setup ====
I2SStream i2s;
MultiOutput multi;
BluetoothA2DPSink a2dp_sink(multi);

// ==== Volume Meter Class ====
class StereoVolumeMeter : public AudioStream {
public:
StereoVolumeMeter() {}

virtual size_t write(const uint8_t data, size_t len) {
const int16_t samples_data = (const int16_t*)data;
int frames = len / 4; // 4 bytes per stereo frame (16 bits left + 16 bits right)

int32_t sumL = 0;
int32_t sumR = 0;

for (int i = 0; i < frames; i++) {
  int16_t left = samples_data[i * 2];     // even indexes = left
  int16_t right = samples_data[i * 2 + 1]; // odd indexes = right

  sumL += abs(left);
  sumR += abs(right);
}

int avgL = sumL / frames;
int avgR = sumR / frames;

// Debug: Output volume levels for both left and right channels
Serial.print("Volume Left: ");
Serial.print(avgL);
Serial.print("  Volume Right: ");
Serial.println(avgR);

showVolumeOnLEDs(avgL, avgR);

return len;

}

void showVolumeOnLEDs(int volumeL, int volumeR) {
// Increase sensitivity by scaling the volume values
volumeL *= 10; // Increase volume sensitivity by a factor of 10
volumeR *= 10; // Increase volume sensitivity by a factor of 10

// Make sure the volume is not larger than the max value (32767)
volumeL = min(volumeL, 32767);
volumeR = min(volumeR, 32767);

// Map volume to LED count (increased sensitivity)
int ledsL = map(volumeL, 0, 32767, 0, NUM_LEDS);
int ledsR = map(volumeR, 0, 32767, 0, NUM_LEDS);

// Debug: Output LED count based on volume for both channels
Serial.print("LEDs Left: ");
Serial.print(ledsL);
Serial.print("  LEDs Right: ");
Serial.println(ledsR);

// Left Strip (GPIO4) - Dynamic color based on volume
for (int i = 0; i < NUM_LEDS; i++) {
  ledsLeft[i] = (i < ledsL) ? getColorForVolume(volumeL) : CRGB::Black;
}

// Right Strip (GPIO2) - Dynamic color based on volume
for (int i = 0; i < NUM_LEDS; i++) {
  ledsRight[i] = (i < ledsR) ? getColorForVolume(volumeR) : CRGB::Black;
}

FastLED.show();

}

CRGB getColorForVolume(int volume) {
if (volume < 10000) return CRGB::Green; // Low volume -> Green
else if (volume < 20000) return CRGB::Yellow; // Medium volume -> Yellow
else return CRGB::Red; // High volume -> Red
}
};

// Create instance of StereoVolumeMeter
StereoVolumeMeter myVolumeMeter;

void setup() {
// Initialize Serial monitor for debugging
Serial.begin(115200);

// ==== Setup LEDs ====
FastLED.addLeds<WS2812B, DATA_PIN_LEFT, GRB>(ledsLeft, NUM_LEDS);
FastLED.addLeds<WS2812B, DATA_PIN_RIGHT, GRB>(ledsRight, NUM_LEDS);
FastLED.clear();
FastLED.show();

// ==== Setup Audio ====
auto cfg = i2s.defaultConfig();

cfg.sample_rate = 44100;
cfg.bits_per_sample = 16; // 16-bit
cfg.channels = 2;
cfg.i2s_format = I2S_MSB_FORMAT;

cfg.pin_bck = 33; // BCLK
cfg.pin_ws = 15; // LRCK / WS
cfg.pin_data = 13; // DATA

// ==== Buffer Size and Count ====
cfg.buffer_size = 1024; // Set buffer size to 1024 as you mentioned
cfg.buffer_count = 4; // You can adjust buffer count for better stability

i2s.begin(cfg);

multi.add(i2s); // First output: I2S DAC
multi.add(myVolumeMeter); // Second output: our own StereoVolumeMeter

a2dp_sink.start("SOUNDit2"); // Bluetooth Device Name
}

void loop() {

}

[pschatzmann]

Hmm, the VolumeMeter already supports multiple channels, so why did you create your own class?

[cocowayco]

You suggested to create a multiple output to send the data to the Volume meter

[pschatzmann]

OK, I see, you process the update of the LEDs in your custom StereoVolumeMeter instead of the loop

[cocowayco]

It shouldn't be critical where to do it. isn'it?

[pschatzmann]

It depends how much delay is added: It does not make any difference if it is very fast.
If a condiderable delay is added, then it is better to do it in the loop.

[pschatzmann]

There was indeed a bug in the VolumeMeter. I committed a correction which should resolve the issue.
Don't forget to set the core debug level, so that you can see any A2DP errors or warnings....

[Ives-Heymans]

Thank you Phil, Confirmed - fixed.

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________________________________ From: Phil Schatzmann ***@***.***> Sent: Tuesday, April 29, 2025 9:47 PM To: pschatzmann/ESP32-A2DP ***@***.***> Cc: Ives-Heymans ***@***.***>; Comment ***@***.***> Subject: Re: [pschatzmann/ESP32-A2DP] ESP32 Wroom 32E A2DP sink + sound reactive Led Stripe (Discussion #703) There was indeed a bug in the VolumeMeter. I committed a correction<pschatzmann/arduino-audio-tools@e8497cd> which should resolve the issue. Don't forget to set the core debug level, so that you can see any A2DP errors or warnings.... — Reply to this email directly, view it on GitHub<#703 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/A2TVDDBVQHNSDRYGK4QKDFT237JNLAVCNFSM6AAAAAB3WEBJSSVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEOJYGQ4DEOA>. You are receiving this because you commented.Message ID: ***@***.***>