Play music using arduino uno and tpa3118

Using Arduino Storage
1

I made a project to play music from the sd card reader using arduino uno and the tpa3118 mono amplifier. the project scheme is as follows:

Untitled Sketch 2_bb
Untitled Sketch 2_bb1920×1949 182 KB

The code I use is the following:


#include <Arduino.h>
#include "SD.h"
#define SD_ChipSelectPin 4
#include "TMRpcm.h"
#include "SPI.h"

TMRpcm tmrpcm;

void setup()
{
  tmrpcm.speakerPin = 9;
  Serial.begin(9600);
  if (!SD.begin(SD_ChipSelectPin))
  {
    Serial.println('SD fail');
    return;
  }

  tmrpcm.setVolume(5);
  tmrpcm.play("audio.wav");
}

void loop()
{
  // put your main code here, to run repeatedly:
}

The problem is that if I increase the volume of the potentiometer to more than a quarter, a very strong background noise appears and the music is no longer heard well. Audio files are in .wav format. I think that I should use an input filter in the amplifier, which will eliminate the background noise. For the amplifier I use a 12V, 2A source. Does anyone have an idea how I could solve the background noise problem?

2

Is it a high-pitch whine?

I've never used TMRpcm but since the regular Arduino doesn't have a DAC (no true-analog output) it's actually PWM and it's putting-out a 5V PWM signal even with "silence".

You probably need a low-pass filter. Do you know the PWM frequency? "Full power" PWM can potentially do "bad things" to an audio amplifier.

And, I believe it's only 8-bits at up-to 32kHz so it's not exactly "high fidelity".

...Class D amplifiers are basically PWM too but it's usually very high frequency, way above the audio range and better filtered-out, usually with an LC filter.

3

Thanks for the reply. Unfortunately I don't know the pwm frequency. yes, is it a high-pitch whine. I will try to use a low pass filter to see if it has any results.

4

HI!! Do you have any pictures do how you made these connections? I´m a hard time making it work! Thanks in advance

5

download latest tonos de llamada 2023 for free as mp3 to add to andruino and tpa3118

6

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