Max9814 to mp3 sdfat example

[luke2023]

I have made a beTA version of adc to mp3 example,but I don't have max9814 now ,so I'll simply upload my beta code
Question ; I don't know if I need to create a empty mp3

[luke2023]

V0.1

////input:gpio 34
#include "Arduino.h"
#include "AudioTools.h"
#include "SdFat.h"
const uint16_t sample_rate =44100;
AnalogAudioStream in; 
int channels = 1;
SdFat SD;
File audioFile;                                                   // final output stream
EncodedAudioStream out(&audioFile, new MP3EncoderLAME());             // encode as mp3 file  
StreamCopy copier(out, in); // copy i2sStream to CsvStream
// Arduino Setup
void setup(void) {
  Serial.begin(115200);
  AudioLogger::instance().begin(Serial, AudioLogger::Info);

  // RX automatically uses port 0 with pins GPIO34,GPIO35
  auto cfgRx = in.defaultConfig(RX_MODE);
  cfgRx.sample_rate = sample_rate;
  cfgRx.channels = channels;
  in.begin(cfgRx);

 auto cfg = noise.defaultConfig();
  cfg.sample_rate = sample_rate;
  cfg.channels = channels;
  cfg.bits_per_sample = 16;
  
  out.begin(cfg);
SD.begin(SdSpiConfig(PIN_CS, DEDICATED_SPI, SD_SCK_MHZ(2)));
  audioFile = SD.open("/test/002.mp3", O_WRITE | O_CREAT);//how to create empty mp3 with esp32?
}

// Arduino loop - copy data 
void loop() {
  copier.copy();
}

[pschatzmann]

You need to add some logic to close the file: otherwise it will be empty.
To overwrite the file you can just move to the beginning after opening it. If I remember right it's with audioFile.seek(0)
I am not sure if this logic will not work: You define what needs to be done with the file even before it (really) exists.

[luke2023]

@pschatzmann Thank you for your suggestion!And do I need to create a empty mp3 file in my computer?And what does this "o_creat"and "o_write"means?

audioFile = SD.open("/test/002.mp3", O_WRITE | O_CREAT);

[luke2023]

@pschatzmann Thank you for your suggestion!And do I need to create a empty mp3 file in my computer?And what does this "o_creat"and "o_write"means?

audioFile = SD.open("/test/002.mp3", O_WRITE | O_CREAT);

[pschatzmann]

Google is your friend: this has nothing to do with my library!

[luke2023]

@pschatzmann hi,is this normal?thank you!