I have a Teensy 3.2 soldered on Top of Teensy Audio Board with SGTL5000.
Line In connection is soldered to ground.
Output is USB Audio, Clock of Teensy is 96 MHz
USB 5V is disconnected, Power is 9V battery with 5V linear regulator
Following sketch i am using:
#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>
// GUItool: begin automatically generated code
AudioInputI2S i2s1; //xy=236,337
AudioOutputUSB usb2; //xy=518,247
AudioOutputI2S i2s2; //xy=518,311
AudioConnection patchCord1(i2s1, 0, usb2, 0);
AudioConnection patchCord2(i2s1, 0, i2s2, 0);
AudioConnection patchCord3(i2s1, 1, usb2, 1);
AudioConnection patchCord4(i2s1, 1, i2s2, 1);
AudioControlSGTL5000 sgtl5000_1; //xy=376,109
// GUItool: end automatically generated code
void setup() {
AudioMemory(10);
sgtl5000_1.enable();
sgtl5000_1.inputSelect(AUDIO_INPUT_LINEIN);
sgtl5000_1.volume(0.8); // headphone volume
sgtl5000_1.adcHighPassFilterDisable(); // reduction of noise floor in some cases
sgtl5000_1.lineInLevel(0);
}
void loop() {
while(1);
}
I record the Audio Ouput with Adobe Audition and i get following graph.
I have amplified the audio a little, so that it can be seen. It always can be heared direct when connecting a headphone to the teensy audio board.
I have recorded the audio, but i do not know how to submit this mp3 file.
I made several tests with the audio board. USB Audio ouput from PC to Teensy generated absolute no noise. Line In always has a lot of noise, even when setting Line In to 0 dB.
Question: Is this normal behavior of the Audio board and if Yes, which Audio Board could be a replacement with much better Signal to Noise ratio of the Line Input.
Thanks in advance
Line In connection is soldered to ground.
Output is USB Audio, Clock of Teensy is 96 MHz
USB 5V is disconnected, Power is 9V battery with 5V linear regulator
Following sketch i am using:
#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>
// GUItool: begin automatically generated code
AudioInputI2S i2s1; //xy=236,337
AudioOutputUSB usb2; //xy=518,247
AudioOutputI2S i2s2; //xy=518,311
AudioConnection patchCord1(i2s1, 0, usb2, 0);
AudioConnection patchCord2(i2s1, 0, i2s2, 0);
AudioConnection patchCord3(i2s1, 1, usb2, 1);
AudioConnection patchCord4(i2s1, 1, i2s2, 1);
AudioControlSGTL5000 sgtl5000_1; //xy=376,109
// GUItool: end automatically generated code
void setup() {
AudioMemory(10);
sgtl5000_1.enable();
sgtl5000_1.inputSelect(AUDIO_INPUT_LINEIN);
sgtl5000_1.volume(0.8); // headphone volume
sgtl5000_1.adcHighPassFilterDisable(); // reduction of noise floor in some cases
sgtl5000_1.lineInLevel(0);
}
void loop() {
while(1);
}
I record the Audio Ouput with Adobe Audition and i get following graph.
I have amplified the audio a little, so that it can be seen. It always can be heared direct when connecting a headphone to the teensy audio board.
I have recorded the audio, but i do not know how to submit this mp3 file.
I made several tests with the audio board. USB Audio ouput from PC to Teensy generated absolute no noise. Line In always has a lot of noise, even when setting Line In to 0 dB.
Question: Is this normal behavior of the Audio board and if Yes, which Audio Board could be a replacement with much better Signal to Noise ratio of the Line Input.
Thanks in advance
Last edited: