Send Data to LED while Playing

[bmorse526]

I have the MP3 Decoding working from a Micro SD and playing to an I2S amplifier and being triggered by a PIR sensor. This part is working fine. I have another function that I would like to implement -
Flash LED at rate of sound with brightness being determined by volume of current sound being played.

I found

void audio_process_extern(int16_t* buff, uint16_t len, bool *continueI2S){
  for(int i = 0; i < len; i += 2){
        int16_t data = buff[i];
       // do something with data.... }
}

And when I put it in the ESP32 project I can get the buffer length and data, But then data stream stops going to the I2S Amplifier.

I would like to be able to get a number that indicates the volume and send to the PCM processor to drive an LED while the stream is playing. The only other option I have come up with is a second ESP32 to monitor the sound and to drive the LED - This should be able to be done in one set of hardware. I appreciate any help or advice anyone could provide.

[schreibfaul1]

With audio_process_extern() you get every single sample in int16_t format.

uint16_t vum = audio.getVUlevel();
uint8_t left = vum >> 8; 
uint8_t right = vum & 0x00FF;

this gives you an average value for both channels, the values are between 0...127

[bmorse526]

That would be ideal. But when I try to use it I get no member named getVUlevel exists. All I can find is a getVolumn. Is that the same call?

[schreibfaul1]

strange, the function must have been around for over a year

and is used in the MiniWebRadio project as a level indicator.

[bmorse526]

I think I found the issue. The GIThub source code shows it. I am using VS code for the ESP32 and the library it shows is 2.0.7 - GitHUB show 3.0.8P
Trying to figure out how to force it in VS Code I am using in Platform.ini
lib_deps =

RECOMMENDED

Accept new functionality in a backwards compatible manner and patches

https://github.com/schreibfaul1/ESP32-audioI2S

#esphome/ESP32-audioI2S @ 2.0.7
esphome/ESP32-audioI2S @ 3.0.8P

I get SemanticVersionError: Invalid simple block '3.0.8p'

[bmorse526]

I tried using
https://github.com/schreibfaul1/ESP32-audioI2S.git
Which is supposed to pull the latest from github. But still get the SemanticVersionError: Invalid simple block '3.0.8p' so it will not compile and upload

[bmorse526]

Thank you for your help. I got the Latest Library and cleared the History so now it is compiling and working.

What is the levels that would be expected? So far looks like 0 to over 32000. Is there a built in max?

[schreibfaul1]

Yes, a uint16_t value is returned. This contains both channels "stacked on top of each other",
hence:

• x >> 8;
• x & 0x00FF;