Teensy 3.1 DAC audio output

[adrian]

I take the output of talkie straight from the teensy to my mixing desk and then out to my rack ... no reason why you couldn't feed it back into the teensy audio board as a line in signal ...of course if you don't have a mixing desk, you will have to match inputs and outputs.

A 10uf electrolytic cap on the hot line is a good idea, to remove dc offset.
Here is a picture of the teensy and cap goinginto my 'mobile' interface

[kenzie]

I'm not having luck with this, hopefully if I post my code and circuit someone can tell me where I've gone wrong. Thanks!

using teensy 3.2
minimum code to reproduce:

#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>

AudioSynthWaveform   sine1;          //xy=355,324
AudioOutputAnalog        dac1;           //xy=626,314
AudioConnection          patchCord1(sine1, 0, dac1, 0);

void setup() {
dac1.analogReference(EXTERNAL);
sine1.begin(WAVEFORM_SINE);
sine1.amplitude(1);
sine1.offset(0);
sine1.frequency(440);
sine1.phase(0);
}

void loop() {    

}

circuit:
(I measured 0.4v-ish from my phone playing a test tone, but couldn't get an ac measurement from the teensy DAC)
- pin A14 is the circuit input, the output is connected to "line in" on a powered speaker

[Frank B]

You have no AudioMemory().