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Topic: MP3 Shield Trigger  (Read 963 times) previous topic - next topic

Ad120

Hello,
I'm using this MP3 Shield Trigger code that runs different mp3 tracks base on the button you push.
It works OK but every time a track ends it won't start unless 1. I push the stop button 2. I play another track (which starts with no problem) .
When I push some other button the tracks switch with no problem so its basically a problem with the way the track ends in the code.
I was wondering how to change the code so it will allow the same track to be played again even if it is the same track that was the last one to be playing.
thank you!

Code: [Select]
/*
  MP3 Shield Trigger
  by: Jim Lindblom
      SparkFun Electronics
  date: September 23, 2013

  This is an example MP3 trigger sketch for the SparkFun MP3 Shield.
  Pins 0, 1, 5, 10, A0, A1, A2, A3, and A4 are setup to trigger tracks
  "track001.mp3", "track002.mp3", etc. on an SD card loaded into
  the shield. Whenever any of those pins are shorted to ground,
  their respective track will start playing.

  When a new pin is triggered, any track currently playing will
  stop, and the new one will start.

  A5 is setup to globally STOP playing a track when triggered.

  If you need more triggers, the shield's jumpers on pins 3 and 4
  (MIDI-IN and GPIO1) can be cut open and used as additional
  trigger pins. Also, because pins 0 and 1 are used as triggers
  Serial is not available for debugging. Disable those as
  triggers if you want to use serial.

  Much of this code was grabbed from the FilePlayer example
  included with the SFEMP3Shield library. Major thanks to Bill
  Porter and Michael Flaga, again, for this amazing library!
*/

#include <SPI.h>           // SPI library
#include <SdFat.h>         // SDFat Library
#include <SdFatUtil.h>     // SDFat Util Library
#include <SFEMP3Shield.h>  // Mp3 Shield Library

SdFat sd; // Create object to handle SD functions

SFEMP3Shield MP3player; // Create Mp3 library object
// These variables are used in the MP3 initialization to set up
// some stereo options:
const uint8_t volume = 0; // MP3 Player volume 0=max, 255=lowest (off)
const uint16_t monoMode = 1;  // Mono setting 0=off, 3=max

/* Pin setup */
#define TRIGGER_COUNT 9
int triggerPins[TRIGGER_COUNT] = {0, 1, 5, 10, A0, A1, A2, A3, A4};
int stopPin = A5; // This pin triggers a track stop.
int lastTrigger = 0; // This variable keeps track of which tune is playing

void setup()
{
  /* Set up all trigger pins as inputs, with pull-ups activated: */
  for (int i=0; i<TRIGGER_COUNT; i++)
  {
    pinMode(triggerPins[i], INPUT_PULLUP);
  }
  pinMode(stopPin, INPUT_PULLUP);

  initSD();  // Initialize the SD card
  initMP3Player(); // Initialize the MP3 Shield
}

// All the loop does is continuously step through the trigger
//  pins to see if one is pulled low. If it is, it'll stop any
//  currently playing track, and start playing a new one.
void loop()
{
  for (int i=0; i<TRIGGER_COUNT; i++)
  {
    if ((digitalRead(triggerPins[i]) == LOW) && ((i+1) != lastTrigger))
    {
      lastTrigger = i+1; // Update lastTrigger variable to current trigger
      /* If another track is playing, stop it: */
      if (MP3player.isPlaying())
        MP3player.stopTrack();

      /* Use the playTrack function to play a numbered track: */
      uint8_t result = MP3player.playTrack(lastTrigger);
      // An alternative here would be to use the
      //  playMP3(fileName) function, as long as you mapped
      //  the file names to trigger pins.

      if (result == 0)  // playTrack() returns 0 on success
      {
        // Success
      }
      else // Otherwise there's an error, check the code
      {
        // Print error code somehow, someway
      }
    }
  }
  // After looping through and checking trigger pins, check to
  //  see if the stopPin (A5) is triggered.
  if (digitalRead(stopPin) == LOW)
  {
    lastTrigger = 0; // Reset lastTrigger
    // If another track is playing, stop it.
    if (MP3player.isPlaying())
      MP3player.stopTrack();
  }
}

// initSD() initializes the SD card and checks for an error.
void initSD()
{
  //Initialize the SdCard.
  if(!sd.begin(SD_SEL, SPI_HALF_SPEED))
    sd.initErrorHalt();
  if(!sd.chdir("/"))
    sd.errorHalt("sd.chdir");
}

// initMP3Player() sets up all of the initialization for the
// MP3 Player Shield. It runs the begin() function, checks
// for errors, applies a patch if found, and sets the volume/
// stero mode.
void initMP3Player()
{
  uint8_t result = MP3player.begin(); // init the mp3 player shield
  if(result != 0) // check result, see readme for error codes.
  {
    // Error checking can go here!
  }
  MP3player.setVolume(volume, volume);
  MP3player.setMonoMode(monoMode);
}

PaulS

Quote
I was wondering how to change the code so it will allow the same track to be played again even if it is the same track that was the last one to be playing.
Get rid of the code that compares the track to be played (based on the switch that was pressed) to the last track played (lastTrigger). That would be the " && ((i+1) != lastTrigger)" of the if statement.
The art of getting good answers lies in asking good questions.

Ad120

It took me a while to test this but it works - thank you very much!

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