Music Player for LPC1768 and MAPLE Board

Dependencies:   SDFileSystem mbed

Files at this revision

API Documentation at this revision

Comitter:
marutsu
Date:
Mon Feb 03 08:58:23 2014 +0000
Commit message:
mbed(LPC1768),MAPLE???,MARY-UB????????????????MicroSD????Music?????wave????????????

Changed in this revision

SDFileSystem.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
wave_player_appbd/wave_player.cpp Show annotated file Show diff for this revision Revisions of this file
wave_player_appbd/wave_player.h Show annotated file Show diff for this revision Revisions of this file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SDFileSystem.lib	Mon Feb 03 08:58:23 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/SDFileSystem/#c8f66dc765d4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Feb 03 08:58:23 2014 +0000
@@ -0,0 +1,44 @@
+#include "mbed.h"
+#include "SDFileSystem.h"
+#include "wave_player.h"
+
+#include <iostream>
+#include <vector>
+#include <string>
+
+SDFileSystem sd(p5, p6, p7, p20, "sd");  //SD card Slot
+AnalogOut DACout(p18);                   //Analog Output
+PwmOut sounder(p26);                     //PWM Sounder Output
+wave_player waver(&DACout, &sounder);    //wave player object
+
+int main() {
+    string DIRPATH("/sd/Music");
+    DIR *dir;
+    struct dirent *entry;
+    FILE *wave_file;
+    vector<string> file_list;
+    int num_file,i;
+    string file_name;
+    
+    dir = opendir(DIRPATH.c_str());
+    if ( dir != NULL ) {
+        while ( (entry = readdir(dir)) != NULL ) {
+            file_list.push_back(entry -> d_name);
+        }
+        num_file = file_list.size();
+        for(i = 0; i < num_file; i++){
+            std::cout << "File No."  << i + 1 << " " << file_list[i] << std::endl;
+            }
+        sounder.period(1.0/400000.0);
+        while(1){
+            std::cout << "Input File Number:";
+            std::cin >> i;
+            file_name = file_name.erase() + DIRPATH + "/" +file_list[i-1];
+            wave_file=fopen(file_name.c_str(),"r");
+            waver.play(wave_file);
+            fclose(wave_file);
+        }
+    }
+    closedir(dir);
+    return 0;
+}
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Mon Feb 03 08:58:23 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/a9913a65894f
\ No newline at end of file
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wave_player_appbd/wave_player.cpp	Mon Feb 03 08:58:23 2014 +0000
@@ -0,0 +1,218 @@
+//-----------------------------------------------------------------------------
+// a sample mbed library to play back wave files.
+//
+// explanation of wave file format.
+// https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
+
+// if VERBOSE is uncommented then the wave player will enter a verbose
+// mode that displays all data values as it reads them from the file
+// and writes them to the DAC.  Very slow and unusable output on the DAC,
+// but useful for debugging wave files that don't work.
+//#define VERBOSE
+
+
+#include <mbed.h>
+#include <stdio.h>
+#include <wave_player.h>
+
+
+//-----------------------------------------------------------------------------
+// constructor -- accepts an mbed pin to use for AnalogOut.  Only p18 will work
+wave_player::wave_player(AnalogOut *_dac, PwmOut *_pwm)
+{  
+
+    
+  wave_PWM= _pwm;  
+  wave_DAC=_dac;
+  wave_DAC->write_u16(32768);        //DAC is 0-3.3V, so idles at ~1.6V
+  *wave_PWM=32768;
+  verbosity=0;
+}
+
+//-----------------------------------------------------------------------------
+// if verbosity is set then wave player enters a mode where the wave file
+// is decoded and displayed to the screen, including sample values put into
+// the DAC FIFO, and values read out of the DAC FIFO by the ISR.  The DAC output
+// itself is so slow as to be unusable, but this might be handy for debugging
+// wave files that don't play
+//-----------------------------------------------------------------------------
+void wave_player::set_verbosity(int v)
+{
+  verbosity=v;
+}
+
+//-----------------------------------------------------------------------------
+// player function.  Takes a pointer to an opened wave file.  The file needs
+// to be stored in a filesystem with enough bandwidth to feed the wave data.
+// LocalFileSystem isn't, but the SDcard is, at least for 22kHz files.  The
+// SDcard filesystem can be hotrodded by increasing the SPI frequency it uses
+// internally.
+//-----------------------------------------------------------------------------
+void wave_player::play(FILE *wavefile)
+{
+        unsigned chunk_id,chunk_size,channel;
+        unsigned data,samp_int,i;
+        short unsigned dac_data;
+        long long slice_value;
+        char *slice_buf;
+        short *data_sptr;
+        unsigned char *data_bptr;
+        int *data_wptr;
+        FMT_STRUCT wav_format;
+        long slice,num_slices;
+  DAC_wptr=0;
+  DAC_rptr=0;
+  for (i=0;i<256;i+=2) {
+    DAC_fifo[i]=0;
+    DAC_fifo[i+1]=3000;
+  }
+  DAC_wptr=4;
+  DAC_on=0;
+
+  fread(&chunk_id,4,1,wavefile);
+  fread(&chunk_size,4,1,wavefile);
+  while (!feof(wavefile)) {
+    if (verbosity)
+      printf("Read chunk ID 0x%x, size 0x%x\n",chunk_id,chunk_size);
+    switch (chunk_id) {
+      case 0x46464952:
+        fread(&data,4,1,wavefile);
+        if (verbosity) {
+          printf("RIFF chunk\n");
+          printf("  chunk size %d (0x%x)\n",chunk_size,chunk_size);
+          printf("  RIFF type 0x%x\n",data);
+        }
+        break;
+      case 0x20746d66:
+        fread(&wav_format,sizeof(wav_format),1,wavefile);
+        if (verbosity) {
+          printf("FORMAT chunk\n");
+          printf("  chunk size %d (0x%x)\n",chunk_size,chunk_size);
+          printf("  compression code %d\n",wav_format.comp_code);
+          printf("  %d channels\n",wav_format.num_channels);
+          printf("  %d samples/sec\n",wav_format.sample_rate);
+          printf("  %d bytes/sec\n",wav_format.avg_Bps);
+          printf("  block align %d\n",wav_format.block_align);
+          printf("  %d bits per sample\n",wav_format.sig_bps);
+        }
+        if (chunk_size > sizeof(wav_format))
+          fseek(wavefile,chunk_size-sizeof(wav_format),SEEK_CUR);
+        break;
+      case 0x61746164:
+// allocate a buffer big enough to hold a slice
+        slice_buf=(char *)malloc(wav_format.block_align);
+        if (!slice_buf) {
+          printf("Unable to malloc slice buffer");
+          exit(1);
+        }
+        num_slices=chunk_size/wav_format.block_align;
+        samp_int=1000000/(wav_format.sample_rate);
+        if (verbosity) {
+          printf("DATA chunk\n");
+          printf("  chunk size %d (0x%x)\n",chunk_size,chunk_size);
+          printf("  %d slices\n",num_slices);
+          printf("  Ideal sample interval=%d\n",(unsigned)(1000000.0/wav_format.sample_rate));
+          printf("  programmed interrupt tick interval=%d\n",samp_int);
+        }
+
+// starting up ticker to write samples out -- no printfs until tick.detach is called
+        if (verbosity)
+          tick.attach_us(this,&wave_player::dac_out, 500000); 
+        else
+          tick.attach_us(this,&wave_player::dac_out, samp_int); 
+        DAC_on=1; 
+
+// start reading slices, which contain one sample each for however many channels
+// are in the wave file.  one channel=mono, two channels=stereo, etc.  Since
+// mbed only has a single AnalogOut, all of the channels present are averaged
+// to produce a single sample value.  This summing and averaging happens in
+// a variable of type signed long long, to make sure that the data doesn't
+// overflow regardless of sample size (8 bits, 16 bits, 32 bits).
+//
+// note that from what I can find that 8 bit wave files use unsigned data,
+// while 16 and 32 bit wave files use signed data
+//
+        for (slice=0;slice<num_slices;slice+=1) {
+          fread(slice_buf,wav_format.block_align,1,wavefile);
+          if (feof(wavefile)) {
+            printf("Oops -- not enough slices in the wave file\n");
+            exit(1);
+          }
+          data_sptr=(short *)slice_buf;     // 16 bit samples
+          data_bptr=(unsigned char *)slice_buf;     // 8 bit samples
+          data_wptr=(int *)slice_buf;     // 32 bit samples
+          slice_value=0;
+          for (channel=0;channel<wav_format.num_channels;channel++) {
+            switch (wav_format.sig_bps) {
+              case 16:
+                if (verbosity)
+                  printf("16 bit channel %d data=%d ",channel,data_sptr[channel]);
+                slice_value+=data_sptr[channel];
+                break;
+              case 32:
+                if (verbosity)
+                  printf("32 bit channel %d data=%d ",channel,data_wptr[channel]);
+                slice_value+=data_wptr[channel];
+                break;
+              case 8:
+                if (verbosity)
+                  printf("8 bit channel %d data=%d ",channel,(int)data_bptr[channel]);
+                slice_value+=data_bptr[channel];
+                break;
+            }
+          }
+          slice_value/=wav_format.num_channels;
+          
+// slice_value is now averaged.  Next it needs to be scaled to an unsigned 16 bit value
+// with DC offset so it can be written to the DAC.
+          switch (wav_format.sig_bps) {
+            case 8:     slice_value<<=8;
+                        break;
+            case 16:    slice_value+=32768;
+                        break;
+            case 32:    slice_value>>=16;
+                        slice_value+=32768;
+                        break;
+          }
+          dac_data=(short unsigned)slice_value;
+          if (verbosity)
+            printf("sample %d wptr %d slice_value %d dac_data %u\n",slice,DAC_wptr,(int)slice_value,dac_data);
+          DAC_fifo[DAC_wptr]=dac_data;
+          DAC_wptr=(DAC_wptr+1) & 0xff;
+          while (DAC_wptr==DAC_rptr) {
+          }
+        }
+        DAC_on=0;
+        tick.detach();
+        free(slice_buf);
+        break;
+      case 0x5453494c:
+        if (verbosity)
+          printf("INFO chunk, size %d\n",chunk_size);
+        fseek(wavefile,chunk_size,SEEK_CUR);
+        break;
+      default:
+        printf("unknown chunk type 0x%x, size %d\n",chunk_id,chunk_size);
+        data=fseek(wavefile,chunk_size,SEEK_CUR);
+        break;
+    }
+    fread(&chunk_id,4,1,wavefile);
+    fread(&chunk_size,4,1,wavefile);
+  }
+}
+
+
+void wave_player::dac_out()
+{
+  if (DAC_on) {
+#ifdef VERBOSE
+  printf("ISR rdptr %d got %u\n",DAC_rptr,DAC_fifo[DAC_rptr]);
+#endif
+    //scale down Analog voltage by 8 for PC speakers
+    wave_DAC->write_u16(DAC_fifo[DAC_rptr]>>3);
+    //Output to onboard speaker using PWM (Class D Audio Amp!)
+    wave_PWM->write(float(DAC_fifo[DAC_rptr]/65536.0));
+    DAC_rptr=(DAC_rptr+1) & 0xff;
+  }
+}
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wave_player_appbd/wave_player.h	Mon Feb 03 08:58:23 2014 +0000
@@ -0,0 +1,73 @@
+#include <mbed.h>
+
+typedef struct uFMT_STRUCT {
+  short comp_code;
+  short num_channels;
+  unsigned sample_rate;
+  unsigned avg_Bps;
+  short block_align;
+  short sig_bps;
+} FMT_STRUCT;
+
+
+/** wave file player class.
+ *
+ * Example:
+ * @code
+ * #include <mbed.h>
+ * #include <wave_player.h>
+ *
+ * AnalogOut DACout(p18);
+ * wave_player waver(&DACout);
+ *
+ * int main() {
+ *  FILE *wave_file;
+ *  
+ *  printf("\n\n\nHello, wave world!\n");
+ *  wave_file=fopen("/sd/44_8_st.wav","r");
+ *  waver.play(wave_file);
+ *  fclose(wave_file); 
+ * }
+ * @endcode
+ */
+class wave_player {
+
+public:
+/** Create a wave player using a pointer to the given AnalogOut object.
+ *
+ * @param _dac pointer to an AnalogOut object to which the samples are sent.
+ */
+wave_player(AnalogOut *_dac, PwmOut *_pwm);
+
+/** the player function.
+ *
+ * @param wavefile  A pointer to an opened wave file
+ */
+void play(FILE *wavefile);
+
+/** Set the printf verbosity of the wave player.  A nonzero verbosity level
+ * will put wave_player in a mode where the complete contents of the wave
+ * file are echoed to the screen, including header values, and including
+ * all of the sample values placed into the DAC FIFO, and the sample values
+ * removed from the DAC FIFO by the ISR.  The sample output frequency is
+ * fixed at 2 Hz in this mode, so it's all very slow and the DAC output isn't
+ * very useful, but it lets you see what's going on and may help for debugging
+ * wave files that don't play correctly.
+ *
+ * @param v the verbosity level
+ */
+void set_verbosity(int v);
+
+private:
+void dac_out(void);
+int verbosity;
+AnalogOut *wave_DAC;
+PwmOut *wave_PWM;
+Ticker tick;
+unsigned short DAC_fifo[256];
+short DAC_wptr;
+volatile short DAC_rptr;
+short DAC_on;
+};
+
+