Teensy 4: No Blink or sound for Tutorial Part 1 05 'Do More While Playing'

[greycells]

Hi

I'm working through the audio board tutorial using a Teensy 4 and have stumbled at Part 1 05 'Do More While Playing'.

The code below is a simplification of the 1.05 sketch that isolates the problem - that is: I can either play the sound -or- I can blink. But I can't do both!

If I comment out the

pinMode(13, OUTPUT); // LED on pin 13

, the sound will play. If I comment out the block starting

if (playSdWav1.isPlaying() == false) {...}

the LED will blink, but I cannot play and blink together.

Am I missing something obvious?

// Advanced Microcontroller-based Audio Workshop
//
// http://www.pjrc.com/store/audio_tutorial_kit.html
// https://hackaday.io/project/8292-microcontroller-audio-workshop-had-supercon-2015
// 
// Part 1-3: First "Hello World" program, play a music file
//
// WAV files for this and other Tutorials are here:
// http://www.pjrc.com/teensy/td_libs_AudioDataFiles.html

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

AudioPlaySdWav           playSdWav1;
AudioOutputI2S           i2s1;
AudioConnection          patchCord1(playSdWav1, 0, i2s1, 0);
AudioConnection          patchCord2(playSdWav1, 1, i2s1, 1);
AudioControlSGTL5000     sgtl5000_1;

// Use these with the Teensy Audio Shield
#define SDCARD_CS_PIN    10
#define SDCARD_MOSI_PIN  7
#define SDCARD_SCK_PIN   14

// Use these with the Teensy 3.5 & 3.6 SD card
//#define SDCARD_CS_PIN    BUILTIN_SDCARD
//#define SDCARD_MOSI_PIN  11  // not actually used
//#define SDCARD_SCK_PIN   13  // not actually used

// Use these for the SD+Wiz820 or other adaptors
//#define SDCARD_CS_PIN    4
//#define SDCARD_MOSI_PIN  11
//#define SDCARD_SCK_PIN   13

elapsedMillis blinkTime;


void setup() {
  Serial.begin(9600);
  AudioMemory(8);
  sgtl5000_1.enable();
  sgtl5000_1.volume(0.2);
  SPI.setMOSI(SDCARD_MOSI_PIN);
  SPI.setSCK(SDCARD_SCK_PIN);
  if (!(SD.begin(SDCARD_CS_PIN))) {
    while (1) {
      Serial.println("Unable to access the SD card");
      delay(500);
    }
  }
  //Comment this line out, audio plays from SD card
  pinMode(13, OUTPUT); // LED on pin 13
  delay(2000);
}

void loop() {

  //Comment this block out and LED will blink.
  if (playSdWav1.isPlaying() == false) {
    Serial.println("Start playing");
    playSdWav1.play("SDTEST2.WAV");
    delay(10); // wait for library to parse WAV info
  }
  // do nothing while playing...
  // blink the LED without delays
  if (blinkTime < 250) {
    digitalWrite(13, LOW);
  } else if (blinkTime < 500) {
    digitalWrite(13, HIGH);
  } else {
    blinkTime = 0; // start blink cycle over again
  }

  
}

 

[defragster]

T_4 uses pin 13 for SCK - so pin blink needs to move to another pin and supplied LED.

Is this a T_4.0 with a Rev D Audio board? Rev C or before won't work on T_4

If so then the SPI for SD card needs to be these lines commented:

#define SDCARD_CS_PIN    10
#define SDCARD_MOSI_PIN  7
#define SDCARD_SCK_PIN   14

Check the PJRC Audio card page to confirm - the T_4.0 with Rev D can use standard pins IIRC - but the page will indicate that for sure in the appropriate table.

 

[greycells]

Thanks for the reply - I noticed the pin changes for SCK on between Rev C and Rev D (I'm using Rev D) but the SD card worked with CS/MOSI/SCK pins as per Rev C but on Rev D, so I kinda went with it!

I've now updated to:

#define SDCARD_CS_PIN    10
#define SDCARD_MOSI_PIN  11
#define SDCARD_SCK_PIN   13

as per the specs here https://www.pjrc.com/store/teensy3_audio.html

but I guess that means the on board LED is always off limits if using the SD card on Teesny4/Rev D?

Quick follow up, just to improve my understanding: do you know why the SD card still worked with the old config?

 

[Tronder]

"I noticed the pin changes for SCK on between Rev C and Rev D (I'm using Rev D) but the SD card worked with CS/MOSI/SCK pins as per Rev C, but on Rev D"

Yeah, what bugs me is that it DID work just fine (everything except the LED blink, for some reason) with the default settings of:

// Use these with the Teensy Audio Shield
#define SDCARD_CS_PIN 10
#define SDCARD_MOSI_PIN 7
#define SDCARD_SCK_PIN 14

When clearly the 'correct' settings are

#define SDCARD_CS_PIN 10
#define SDCARD_MOSI_PIN 11
#define SDCARD_SCK_PIN 13

So, by correcting these settings, nothing was really gained or achieved (the LED didn't work before the change, but it's most definitely buggered after this change). I might just ignore these useless (as in, being overridden by the compiler anyway) SDCARD settings going forward, lol.

Btw, the default volume of 0.5 blows out my headphones and distort the sound. Volume of 0.2 makes it listenable.