emmanuel63
Well-known member
Hello,
I have made a little sample player with a teensy 3.5.
Samples are stored on SD card. I use the builtin DACs to get a line level audio output. I use a 10 microF cap to remove DC.
I have some noise when playing samples that I can't get rid of. I tried filtering the power supply, I also made test with batteries, I still have this noise. Samples format : wav, 16bits, stereo.
Wit loud samples, the noise is not hearable. But some of my samples fade from loud to zero, and the noise is really annoying. It's a "digital" noise. It's really sounds like "digital artefacts". No noise on the output when nothing is reading.
Here is the code. This is a simplified version, but It reproduce the problem.
Thanks for any help.
Emmanuel
#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>
AudioPlaySdWav playSdWav1;
AudioOutputAnalogStereo dacs1;
AudioConnection patchCord1(playSdWav1, 0, dacs1, 0);
AudioConnection patchCord2(playSdWav1, 1, dacs1, 1);
void setup() {
Serial.begin(9600);
AudioMemory(12);
SD.begin(BUILTIN_SDCARD);
}
void loop() {
if (playSdWav1.isPlaying() == false) {
playSdWav1.play("m_c3.wav");
delay(10);
}
// do nothing while playing...
}
I have made a little sample player with a teensy 3.5.
Samples are stored on SD card. I use the builtin DACs to get a line level audio output. I use a 10 microF cap to remove DC.
I have some noise when playing samples that I can't get rid of. I tried filtering the power supply, I also made test with batteries, I still have this noise. Samples format : wav, 16bits, stereo.
Wit loud samples, the noise is not hearable. But some of my samples fade from loud to zero, and the noise is really annoying. It's a "digital" noise. It's really sounds like "digital artefacts". No noise on the output when nothing is reading.
Here is the code. This is a simplified version, but It reproduce the problem.
Thanks for any help.
Emmanuel
#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>
AudioPlaySdWav playSdWav1;
AudioOutputAnalogStereo dacs1;
AudioConnection patchCord1(playSdWav1, 0, dacs1, 0);
AudioConnection patchCord2(playSdWav1, 1, dacs1, 1);
void setup() {
Serial.begin(9600);
AudioMemory(12);
SD.begin(BUILTIN_SDCARD);
}
void loop() {
if (playSdWav1.isPlaying() == false) {
playSdWav1.play("m_c3.wav");
delay(10);
}
// do nothing while playing...
}