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atomic14 / esp32_audio

Sample code for reading audio samples from the ESP32 ADC using I2S
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Audio Issue: Audio file received from the ESP32 with INMP441 microphone is distorted #7

Closed vjsyong closed 3 years ago

vjsyong commented 3 years ago

Hi,

I currently am using the INMP441 microphone connected to the ESP32 as per the wiring diagram on the github page. I have been able to get the esp32 to connect over wifi to stream the i2s data back. However, I am running into an issue with the quality of the audio received. I have been importing the audio into audacity with the setting.

  1. 16 bit signed PCM
  2. 16000hz sampling rate
  3. Mono channel.

While I am able to hear most of the high level features of the audio, the audio file is generally very distorted and has lots of hissing and popping noises in the background. From watching your previous videos, my first intuition was that it might be a power supply issue, so I added a 1mF capacitor between VCC and GND in order to try to smooth out the electrical noise but to no avail.

Here is sample of the audio received from the ESP32 in a raw format. I have recorded two samples, 1 at 44100hz and the other at 16000hz. The 44100hz sample is a little better but still heavily distorted.

audiosamples.zip

StuartIanNaylor commented 3 years ago

https://drive.google.com/open?id=1FQkvVXz-4xSGMut8JCYTe96_uW_Absuy Stereo 16bit 44100 raw 2x INMP441using https://github.com/atomic14/ICS-43434-breakout-board

I did get 1x INMP441 that just made this horrid cyclic clicking and replaced it was fine so must be defective. They are 3.3v devices but sounds like yours is defective

jonaslimads commented 3 years ago

I was able to remove some noise and hissing by changing to these pins:

i2s_pin_config_t i2sPins = {
    .bck_io_num = 2,
    .ws_io_num = 15,
    .data_out_num = I2S_PIN_NO_CHANGE,
    .data_in_num = 13};

I have also noted that some near cables may interfere with the audio sampling. In fact the inmp441 was touching some USB cable and the audio was horrible, then I moved to a clean area and the output got clean. I'm using the same Audicity settings you are using

StuartIanNaylor commented 3 years ago

I2S is a pure digital signal not analogue you sure you just didn't have your connections right?

badyast commented 2 years ago

My raw audio sounds like yours. In my case i solved it using a powerbank as powersupply.