I am attempting to play a wav file from an SD card using a Teensy 3.5. I am using this buzzer and I have the following code currently:

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

// GUItool: begin automatically generated code
AudioPlaySdWav           playSdWav1;     //xy=557,157
AudioOutputPWM           pwm1;           //xy=889,184
AudioConnection          patchCord1(playSdWav1, 0, pwm1, 0);
AudioConnection          patchCord2(playSdWav1, 1, pwm1, 0);
// GUItool: end automatically generated code

void setup() {
  // put your setup code here, to run once:

void loop() {
  // put your main code here, to run repeatedly:
  while (playSdWav1.isPlaying()) {
    delay (100);

I don't know which pin is supposed to be outputting the PWM signal. I tried searching "patchCord1" to see what the parameters for it are, but was unsuccessful. The code was generated by The Audio System Design Tool.

As for the hardware configuration, I am attempting to wire the I/O pin to various PWM pins (to check for output) with no success. I have GND to Analog Ground and VCC to 3.3V (250 mA max). This is according to this diagram.

Which PIN is the Teensy supposed to output the pulses to?


I can get the buzzer to work by using manual PWM (analogWrite), so I know that it functions.

  • I will edit the question to add a little bit of specifics. But, my question is first, which pin is supposed to be connected to I/O. And second, am I doing this right at all?
    – STF_ZBR
    Sep 19, 2020 at 22:44

1 Answer 1


The documentation implies you have to combine pins 3 and 4.

Here is a circuit diagram:


enter image description here



  • After wiring it this way, I still receive no sound. But, I am noticing that the serial monitor is constantly entering "Play." But, it seems it shouldn't do that until the sound has completed? The sound is 5 seconds and it's doing about 10 per second.
    – STF_ZBR
    Sep 22, 2020 at 1:08

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