[Newbs] code problem with Arduino Uno + Waveshield

Hi,

My project team trying to use Arduino Uno + wave shield play wave file from the SD card on the shield. We are trying to use two buttons to control the songs as followed:

  1. When one pressed play next, and another one pressed to play previous. ( Two buttons are connected to the digital input on the wave shield. We tested it with the pin 13 LED, and it worked fine. )
  2. It stops play any song after the last song.

The following code is developed based on the example code from wave shield. We could really use help here. Thanks for any advise or suggestion.

Here is the code

 #include <FatReader.h>
#include <SdReader.h>
#include <avr/pgmspace.h>
#include "WaveUtil.h"
#include "WaveHC.h"


SdReader card;    // This object holds the information for the card
FatVolume vol;    // This holds the information for the partition on the card
FatReader root;   // This holds the information for the filesystem on the card
FatReader f;      // This holds the information for the file we're play

WaveHC wave;      // This is the only wave (audio) object, since we will only play one at a time

#define DEBOUNCE 5  // button debouncer

// here is where we define the buttons that we'll use. button "1" is the first, button "6" is the 6th, etc
byte buttons[] = {14, 15};
// This handy macro lets us determine how big the array up above is, by checking the size
#define NUMBUTTONS sizeof(buttons)
// we will track if a button is just pressed, just released, or 'pressed' (the current state
volatile byte pressed[NUMBUTTONS], justpressed[NUMBUTTONS], justreleased[NUMBUTTONS];

char* sounds[]={"MustangSoundA.wav","MustangSoundB.wav","TeslaSoundA.wav","TeslaSoundB.wav","TrainSoundA.wav","TrainSoundB.wav"};

int whichSound=0;
// this handy function will return the number of bytes currently free in RAM, great for debugging!   
int freeRam(void)
{
  extern int  __bss_end; 
  extern int  *__brkval; 
  int free_memory; 
  if((int)__brkval == 0) {
    free_memory = ((int)&free_memory) - ((int)&__bss_end); 
  }
  else {
    free_memory = ((int)&free_memory) - ((int)__brkval); 
  }
  return free_memory; 
} 

void sdErrorCheck(void)
{
  if (!card.errorCode()) return;
  putstring("\n\rSD I/O error: ");
  Serial.print(card.errorCode(), HEX);
  putstring(", ");
  Serial.println(card.errorData(), HEX);
  while(1);
}

void setup() {
  byte i;
  
  // set up serial port
  Serial.begin(9600);
  putstring_nl("WaveHC with ");
  Serial.print(NUMBUTTONS, DEC);
  putstring_nl("buttons");
  
  putstring("Free RAM: ");       // This can help with debugging, running out of RAM is bad
  Serial.println(freeRam());      // if this is under 150 bytes it may spell trouble!
  
  // Set the output pins for the DAC control. This pins are defined in the library
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
 
  // pin13 LED
  pinMode(13, OUTPUT);
 
  // Make input & enable pull-up resistors on switch pins
  for (i=0; i< NUMBUTTONS; i++) {
    pinMode(buttons[i], INPUT);
    digitalWrite(buttons[i], HIGH);
  }
  
  //  if (!card.init(true)) { //play with 4 MHz spi if 8MHz isn't working for you
  if (!card.init()) {         //play with 8 MHz spi (default faster!)  
    putstring_nl("Card init. failed!");  // Something went wrong, lets print out why
    sdErrorCheck();
    while(1);                            // then 'halt' - do nothing!
  }
  
  // enable optimize read - some cards may timeout. Disable if you're having problems
  card.partialBlockRead(true);
 
// Now we will look for a FAT partition!
  uint8_t part;
  for (part = 0; part < 5; part++) {     // we have up to 5 slots to look in
    if (vol.init(card, part)) 
      break;                             // we found one, lets bail
  }
  if (part == 5) {                       // if we ended up not finding one  :(
    putstring_nl("No valid FAT partition!");
    sdErrorCheck();      // Something went wrong, lets print out why
    while(1);                            // then 'halt' - do nothing!
  }
  
  // Lets tell the user about what we found
  putstring("Using partition ");
  Serial.print(part, DEC);
  putstring(", type is FAT");
  Serial.println(vol.fatType(),DEC);     // FAT16 or FAT32?
  
  // Try to open the root directory
  if (!root.openRoot(vol)) {
    putstring_nl("Can't open root dir!"); // Something went wrong,
    while(1);                             // then 'halt' - do nothing!
  }
  
  // Whew! We got past the tough parts.
  putstring_nl("Ready!");
  
  TCCR2A = 0;
  TCCR2B = 1<<CS22 | 1<<CS21 | 1<<CS20;

  //Timer2 Overflow Interrupt Enable
  TIMSK2 |= 1<<TOIE2;


}

SIGNAL(TIMER2_OVF_vect) {
  check_switches();
}

void check_switches()
{
  static byte previousstate[NUMBUTTONS];
  static byte currentstate[NUMBUTTONS];
  byte index;

  for (index = 0; index < NUMBUTTONS; index++) {
    currentstate[index] = digitalRead(buttons[index]);   // read the button
    
    /*     
    Serial.print(index, DEC);
    Serial.print(": cstate=");
    Serial.print(currentstate[index], DEC);
    Serial.print(", pstate=");
    Serial.print(previousstate[index], DEC);
    Serial.print(", press=");
    */
    
    //[zhou]  I think you only care when state has changed
    if (currentstate[index] != previousstate[index]) {
      //digital HIGH means NOT pressed,  digital LOW means pressed
      if ((previousstate[index] == HIGH) && (currentstate[index] == LOW)) {
          // just pressed
          pressed[index] = 1;
      }     
    }   
    previousstate[index] = currentstate[index];   // keep a running tally of the buttons
  }
}


void loop() {
  byte i;
  
  if (pressed[0]) {
    pressed[0] = 0;
    whichSound = (whichSound+1)%6; 
    playfile(sounds[whichSound]);
    
  }
  else if (pressed[1]) {
      pressed[1] = 0;
      whichSound = (whichSound+5)%6;    //By this, you are guaranteed not to overflow the array
      playfile(sounds[whichSound]);      
  }
}



// Plays a full file from beginning to end with no pause.
void playcomplete(char *name) {
  // call our helper to find and play this name
  playfile(name);
  while (wave.isplaying) {
  // do nothing while its playing
  }
  // now its done playing
}

void playfile(char *name) {
  // see if the wave object is currently doing something
  if (wave.isplaying) {// already playing something, so stop it!
    wave.stop(); // stop it
  }
  // look in the root directory and open the file
  if (!f.open(root, name)) {
    putstring("Couldn't open file "); Serial.print(name); return;
  }
  // OK read the file and turn it into a wave object
  if (!wave.create(f)) {
    putstring_nl("Not a valid WAV"); return;
  }
  
  // ok time to play! start playback
  wave.play();
}

what is the problem?

We tested the code, the button didn't work. So we are trying to find out if the code have any problem.

We tested the code, the button didn't work.

Where did you define which pin the switch is connected to? Where did you read whether the switch was pressed?

PaulS:

Where did you define which pin the switch is connected to? Where did you read whether the switch was pressed?

Hi,
Thanks for the reply. I’m sorry I think I put a different code there. I just edited it and the pin switch is defined:

#define DEBOUNCE 5

byte buttons = {14, 15}
#define NUMBUTTONS sizeof(buttons)



And we use the following code to checkswitch status.



SIGNAL(TIMER2_OVF_vect) {
 check_switches();
}

void check_switches()
{
 static byte previousstate[NUMBUTTONS];
 static byte currentstate[NUMBUTTONS];
 byte index;

for (index = 0; index < NUMBUTTONS; index++) {
   currentstate[index] = digitalRead(buttons[index]);   // read the button
   
   /*    
   Serial.print(index, DEC);
   Serial.print(": cstate=");
   Serial.print(currentstate[index], DEC);
   Serial.print(", pstate=");
   Serial.print(previousstate[index], DEC);
   Serial.print(", press=");
   */
   
   //I think you only care when state has changed
   if (currentstate[index] != previousstate[index]) {
     //digital HIGH means NOT pressed,  digital LOW means pressed
     if ((previousstate[index] == HIGH) && (currentstate[index] == LOW)) {
         // just pressed
         pressed[index] = 1;
     }    
   }  
   previousstate[index] = currentstate[index];   // keep a running tally of the buttons
 }
}

void loop() {
 byte i;
 
 if (pressed[0]) {
   pressed[0] = 0;
   whichSound = (whichSound+1)%6;  
   playfile(sounds[whichSound]);
   
 }
 else if (pressed[1]) {
     pressed[1] = 0;
     whichSound = (whichSound+5)%6;    //By this, you are guaranteed not to overflow the array
     playfile(sounds[whichSound]);      
 }
}






i guess that's what we have for the code.
Can you give any suggestion on how to define which pin the button is connected to?
And is there a way to figure out what is the next song to play when the button is pressed?

I'm sorry I think I put a different code there. I just edited it

Don't do that. Post the correct code in another post.

#define NUMBUTTONS sizeof(buttons)

This only works because buttons is an array of bytes. To be accurate, NUMBUTTONS should be sizeof(buttons)/sizeof(buttons[0]). This way, the number of elements in the array will be correct for any type.

Can you give any suggestion on how to define which pin the button is connected to?

That is that the buttons array is doing.

And is there a way to figure out what is the next song to play when the button is pressed?

That is what whichSound is doing, at least as far as defining the index into the array of song names.

#define NUMBUTTONS sizeof(buttons)

This only works because buttons is an array of bytes. To be accurate, NUMBUTTONS should be sizeof(buttons)/sizeof(buttons[0]). This way, the number of elements in the array will be correct for any type.

Can you give any suggestion on how to define which pin the button is connected to?

That is that the buttons array is doing.

Thanks for the quick reply. We connected two buttons to the digital input pin6 7 on the wave shield. I am just wondering if this is correct code for it?

We connected two buttons to the digital input pin6 7 on the wave shield

Then why did you put values of 14 and 15 in the array?

PaulS:

We connected two buttons to the digital input pin6 7 on the wave shield

Then why did you put values of 14 and 15 in the array?

#define DEBOUNCE 5
byte buttons[] = {6, 7}
#define NUMBUTTONS sizeof(buttons)

Will this be enough to define the buttons that connected to digital input pin6 7? Thanks

Let's time how long it takes to compile and link that code, and upload it to the Arduino, vs. the time it takes to post here and wait for a response.

Compile and link and try it!

PaulS:
Let’s time how long it takes to compile and link that code, and upload it to the Arduino, vs. the time it takes to post here and wait for a response.

Compile and link and try it!

Thanks for the help. I just tried the code. It seems the microcontroller reads the input and somehow produced some sounds. But I think there is problem with the “play next track function”. When I pressed the button it didn’t play the next track, but played all the tracks in a loop. Here is the code I just tried. Can you please check it and give us some advice? Thank you very much.

#include <FatReader.h>
#include <SdReader.h>
#include <avr/pgmspace.h>
#include "WaveUtil.h"
#include "WaveHC.h"


SdReader card;    // This object holds the information for the card
FatVolume vol;    // This holds the information for the partition on the card
FatReader root;   // This holds the information for the filesystem on the card
FatReader f;      // This holds the information for the file we're play

WaveHC wave;      // This is the only wave (audio) object, since we will only play one at a time

#define DEBOUNCE 5  // button debouncer

// here is where we define the buttons that we'll use. button "1" is the first, button "6" is the 6th, etc
byte buttons[] = {6,7};
// This handy macro lets us determine how big the array up above is, by checking the size
#define NUMBUTTONS sizeof(buttons)
// we will track if a button is just pressed, just released, or 'pressed' (the current state
volatile byte pressed[NUMBUTTONS], justpressed[NUMBUTTONS], justreleased[NUMBUTTONS];

char* sounds[]={"1k.wav","2k.wav","3k.wav","4k.wav","5k.wav"};

int whichSound=0;
// this handy function will return the number of bytes currently free in RAM, great for debugging!   
int freeRam(void)
{
  extern int  __bss_end; 
  extern int  *__brkval; 
  int free_memory; 
  if((int)__brkval == 0) {
    free_memory = ((int)&free_memory) - ((int)&__bss_end); 
  }
  else {
    free_memory = ((int)&free_memory) - ((int)__brkval); 
  }
  return free_memory; 
} 

void sdErrorCheck(void)
{
  if (!card.errorCode()) return;
  putstring("\n\rSD I/O error: ");
  Serial.print(card.errorCode(), HEX);
  putstring(", ");
  Serial.println(card.errorData(), HEX);
  while(1);
}

void setup() {
  byte i;
  
  // set up serial port
  Serial.begin(9600);
  putstring_nl("WaveHC with ");
  Serial.print(NUMBUTTONS, DEC);
  putstring_nl("buttons");
  
  putstring("Free RAM: ");       // This can help with debugging, running out of RAM is bad
  Serial.println(freeRam());      // if this is under 150 bytes it may spell trouble!
  
  // Set the output pins for the DAC control. This pins are defined in the library
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
 
  // pin13 LED
  pinMode(13, OUTPUT);
 
  // Make input & enable pull-up resistors on switch pins
  for (i=0; i< NUMBUTTONS; i++) {
    pinMode(buttons[i], INPUT);
    digitalWrite(buttons[i], HIGH);
  }
  
  //  if (!card.init(true)) { //play with 4 MHz spi if 8MHz isn't working for you
  if (!card.init()) {         //play with 8 MHz spi (default faster!)  
    putstring_nl("Card init. failed!");  // Something went wrong, lets print out why
    sdErrorCheck();
    while(1);                            // then 'halt' - do nothing!
  }
  
  // enable optimize read - some cards may timeout. Disable if you're having problems
  card.partialBlockRead(true);
 
// Now we will look for a FAT partition!
  uint8_t part;
  for (part = 0; part < 5; part++) {     // we have up to 5 slots to look in
    if (vol.init(card, part)) 
      break;                             // we found one, lets bail
  }
  if (part == 5) {                       // if we ended up not finding one  :(
    putstring_nl("No valid FAT partition!");
    sdErrorCheck();      // Something went wrong, lets print out why
    while(1);                            // then 'halt' - do nothing!
  }
  
  // Lets tell the user about what we found
  putstring("Using partition ");
  Serial.print(part, DEC);
  putstring(", type is FAT");
  Serial.println(vol.fatType(),DEC);     // FAT16 or FAT32?
  
  // Try to open the root directory
  if (!root.openRoot(vol)) {
    putstring_nl("Can't open root dir!"); // Something went wrong,
    while(1);                             // then 'halt' - do nothing!
  }
  
  // Whew! We got past the tough parts.
  putstring_nl("Ready!");
  
  TCCR2A = 0;
  TCCR2B = 1<<CS22 | 1<<CS21 | 1<<CS20;

  //Timer2 Overflow Interrupt Enable
  TIMSK2 |= 1<<TOIE2;


}

SIGNAL(TIMER2_OVF_vect) {
  check_switches();
}

void check_switches()
{
  static byte previousstate[NUMBUTTONS];
  static byte currentstate[NUMBUTTONS];
  byte index;

  for (index = 0; index < NUMBUTTONS; index++) {
    currentstate[index] = digitalRead(buttons[index]);   // read the button
    
    /*     
    Serial.print(index, DEC);
    Serial.print(": cstate=");
    Serial.print(currentstate[index], DEC);
    Serial.print(", pstate=");
    Serial.print(previousstate[index], DEC);
    Serial.print(", press=");
    */
    
    //I think you only care when state has changed
    if (currentstate[index] != previousstate[index]) {
      //digital HIGH means NOT pressed,  digital LOW means pressed
      if ((previousstate[index] == HIGH) && (currentstate[index] == LOW)) {
          // just pressed
          pressed[index] = 1;
      }     
    }   
    previousstate[index] = currentstate[index];   // keep a running tally of the buttons
  }
}


void loop() {
  byte i;
  
  if (pressed[0]) {
    pressed[0] = 0;
    whichSound = (whichSound+1)%6;  //it's better to avoid using constant number directly here. 
                                    //INstead, define it somewhere or compute it
                                    // you probably need to do something smarter like in playall.cpp to figure out which one is next song
    playfile(sounds[whichSound]);
    
  }
  else if (pressed[1]) {
      pressed[1] = 0;
      whichSound = (whichSound+5)%6;    //By this, you are guaranteed not to overflow the array
      playfile(sounds[whichSound]);      
  }
}



// Plays a full file from beginning to end with no pause.
void playcomplete(char *name) {
  // call our helper to find and play this name
  playfile(name);
  while (wave.isplaying) {
  // do nothing while its playing
  }
  // now its done playing
}

void playfile(char *name) {
  // see if the wave object is currently doing something
  if (wave.isplaying) {// already playing something, so stop it!
    wave.stop(); // stop it
  }
  // look in the root directory and open the file
  if (!f.open(root, name)) {
    putstring("Couldn't open file "); Serial.print(name); return;
  }
  // OK read the file and turn it into a wave object
  if (!wave.create(f)) {
    putstring_nl("Not a valid WAV"); return;
  }
  
  // ok time to play! start playback
  wave.play();
}

The amount of free RAM is not your problem. Get rid of stuff that is not related to your problem.

Forget trying to make the switches DO anything useful for the moment. Forget trying to play songs, for the moment.

Create a sketch that simply reads and prints the state of the switches, once per second. While that sketch is running, press and release the switches. Does the serial output ALWAYS match the actual switch states?

Checking the state of the switches periodically, whatever that mess with the timer means, seems like a strange thing to do. You have a function already that gets called periodically, loop(), and it happens that loop() gets called far more often than your interrupt.

I fail to see what value the timer based interrupt is adding to the sketch.

You should get rid of playComplete. It is not called, and it simply clutters up the sketch.

But I think there is problem with the "play next track function".

What play next track function?