File content as of revision 8:40f37287589a:

//  24/03/2018  update - I appear to be able to address the device and write something, as I am getting an ACK returned from the i2c write() function.
//however if i use the write function with 4 arguments (as opposed to just 1 argument) then it doesnt work
//only works with the 1 argument version!!!


//THIS VERSION WORKED, CHANGED SOME THINGS, THEN CHANGED THEM BACK.  NOW IT NO LONGER WORKS!!!!
#include "mbed.h"
#include "sinelookup.h" 
#include "I2S.h"   
#define sample_freq 8000
DigitalOut myled(LED1);
DigitalOut led2(LED2);
DigitalOut led3(LED3);
Ticker sampletick;
Timer t;
Timer t2;
#include "SDFileSystem.h"     
#include "WOLFSON_config.h"  
Serial pc(USBTX, USBRX); // tx, rx //FOR DEBUGGING PROGRAM USING GNU SCREEN
DigitalOut cs(p8);
I2S i2s(I2S_TRANSMIT,p5,p6,p7);
I2C i2c(p9, p10);
 
SDFileSystem sd(p11, p12, p13, p8, "sd"); // the new pinout that i am using

typedef struct uFMT_STRUCT{
  short comp_code;
  short num_channels;
  unsigned sample_rate;
  unsigned avg_Bps;
  short block_align;
  short sig_bps;
} FMT_STRUCT;

typedef struct uDATA_STRUCT {
  unsigned subchunk2_ID;
  unsigned subchunk2_size;
  char * data_buf;
}DATA_STRUCT;
short hello;
int i = 0;
int h = 0;
short bufflen = 1;
int buffer[1];
int AudioFormat, NumChannels, SampleRate, BitsPerSample ; 
char *slice_buf;
short *data_sptr;
unsigned char *data_bptr;
int *data_wptr;
unsigned channel;
int newvar;
long slice, num_slices;
int verbosity = 0;
int verbosity2 = 0;
int interrupt_condition = 1;
int sampling_freq = 8000;
short Buffer1[8];
short Buffer2[8];
short place_hold1 = 0;
short place_hold2 = 0;
int flag1 = 1;
int flag2 = 0;
int flag3 = 1;
int flag4 = 0;
short value[1];
//long long slice_value;
int slice_value[1];
FILE *my_wav;
FMT_STRUCT wav_format;
DATA_STRUCT wav_data;

Ticker flipper;
//test
void flip() {
    led2  = !led2;
}


void isr()
{
    //buffer[0] = (*data_sptr)>>1;
    //myled = 1;
    //int bufflen = sizeof(buffer);
    if(verbosity){
    printf("buffer data:  %d \n\r",buffer);
    printf("data_sptr data:  %d",data_sptr);
    short value = Buffer1[0];
    printf("value: %d",value);
    }
    //t.start();    

    //t.stop();
    //printf("The time taken was %f seconds\n", t.read());
    //t.reset();
    //myled = 0;
    if(flag1 == 0)
    {
        //access double buffer pt1
        value[0] = Buffer1[place_hold1];
        i2s.write(value,1);//Send next PWM value to amp
        place_hold1 = place_hold1 + 1;
        if(place_hold1 == 8)
        {
            place_hold1 = 0;
            place_hold2 = 0;
            flag1 = 1;
            flag2 = 0;
            flag3 = 1;
        }   
        if(verbosity2 == 1)
        {
          printf("value Buffer1: %d\n\r",value[0]);    
        }        
    }           
    else if(flag2 == 0)
    {
        //access double buffer pt2
        value[0] = Buffer1[place_hold2];
        i2s.write(value,1);//Send next PWM value to amp
        place_hold2 = place_hold2 + 1; 
        if(place_hold2 == 8)
        {
            place_hold1 = 0;
            place_hold2 = 0;
            flag1 = 0;
            flag2 = 1;
            flag3 = 1;
        }   
        if(verbosity2 == 1)
        {
         printf("value Buffer2: %d\n\r",value[0]);      
        }        
    }
    
}
    


void wm8731_setup(int chip_addr, int addr, int cmd){
    addr = addr << 1;
    addr = addr|((cmd >> 8 ))& 0x01;//mess around with order of operations
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( chip_addr );
    i2c.write( addr  );
    i2c.write( cmd );
    i2c.stop(); 
    }
    

void wm8731_config(void){
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_RESET, _WM8731_RESET );//1
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_LLINE_IN, _WM8731_LEFT_LINEIN );//2
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_RLINE_IN, _WM8731_RIGHT_LINEIN );//3
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_LHPHONE_OUT, _WM8731_LEFT_HP );//4 
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_RHPHONE_OUT, _WM8731_RIGHT_HP );//5   
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_ANALOG_PATH, _WM8731_ANALOGAUDIO );//6   
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_DIGITAL_PATH, _WM8731_DIGITALAUDIO );//7   
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_PDOWN_CTRL, _WM8731_POWER );//8   
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_DIGITAL_IF, _WM8731_DAIF );//9   
    wm8731_setup( WM8731_ADDRESS, WM8731_REG_SAMPLING_CTRL, _WM8731_SAMPLING );//10
    }    
    
void wm8731_configTEST(void){
    int addr = WM8731_REG_RESET;
    int cmd = _WM8731_RESET;
    addr = addr << 1;
    addr = addr|((cmd >> 8 ))& 0x01;//mess around with order of operations
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );
    i2c.write( addr  );
    i2c.write( cmd );
    i2c.stop();

    addr = WM8731_REG_LLINE_IN;
    cmd = _WM8731_LEFT_LINEIN;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//take Fergus' suggestion and declare these to known values EARLIER in program
    i2c.write( addr );
    i2c.write( cmd );
    i2c.stop();
    
    
    addr = WM8731_REG_RLINE_IN;
    cmd = _WM8731_RIGHT_LINEIN;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//take Fergus' suggestion and declare these to known values EARLIER in program
    i2c.write( addr );
    i2c.write( cmd );
    i2c.stop();
    
       
    //4
    addr = WM8731_REG_LHPHONE_OUT;
    cmd = _WM8731_LEFT_HP;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );
    i2c.write( addr );//WM8731_REG_LHPHONE_OUT, _WM8731_LEFT_HP   
    i2c.write(cmd);   
    i2c.stop();
      
    //5
    addr = WM8731_REG_RHPHONE_OUT;
    cmd = _WM8731_RIGHT_HP;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//WM8731_REG_RHPHONE_OUT, _WM8731_RIGHT_HP 
    i2c.write( addr );
    i2c.write( cmd );
    i2c.stop();
  
    
    //6
    addr = WM8731_REG_ANALOG_PATH;
    cmd = _WM8731_ANALOGAUDIO;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//WM8731_REG_ANALOG_PATH, _WM8731_ANALOGAUDIO
    i2c.write( addr );
    i2c.write( cmd );
    i2c.stop();
    
    //7
    addr = WM8731_REG_DIGITAL_PATH;
    cmd = _WM8731_DIGITALAUDIO;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//WM8731_REG_DIGITAL_PATH, _WM8731_DIGITALAUDIO
    i2c.write( addr  );
    i2c.write( cmd );
    i2c.stop();
    
    //8
    addr = WM8731_REG_PDOWN_CTRL;
    cmd = _WM8731_POWER;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//WM8731_REG_PDOWN_CTRL, _WM8731_POWER)
    i2c.write( addr  );
    i2c.write( cmd );
    i2c.stop();
    
    
    //9
    addr = WM8731_REG_DIGITAL_IF;
    cmd = _WM8731_DAIF;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );
    i2c.write( addr  );//WM8731_REG_DIGITAL_IF, _WM8731_DAIF
    i2c.write( cmd );
    i2c.stop();

   
    //10
    addr = WM8731_REG_SAMPLING_CTRL;
    cmd = _WM8731_SAMPLING;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;
    i2c.start();
    i2c.write( WM8731_ADDRESS );//WM8731_REG_SAMPLING_CTRL, _WM8731_SAMPLING
    i2c.write( addr  );
    i2c.write( cmd );
    i2c.stop();
    
    
   
    
    //11
    addr = WM8731_REG_ACTIVE_CTRL;
    cmd = _WM8731_ACTIVATE;
    addr = addr << 1;
    addr = addr|((cmd >> 8 )) & 0x01;
    cmd = cmd&0xFF;    
    i2c.start();
    i2c.write( WM8731_ADDRESS );//WM8731_REG_SAMPLING_CTRL, _WM8731_SAMPLING
    i2c.write( addr  );
    i2c.write( cmd );//there is also a deactive version!!
    i2c.stop();
    
    
    
    }

int main() {
    FMT_STRUCT wav_format;
    char data[2];
    pc.printf("Beginning of program\n");
    data[0] = 0x0F;
    data[1] = 0x00;
    FILE *my_wav;
    //my_wav = fopen("/sd/mydir/gp40.wav", "rb");//i think that it is "w" for write, "r"  for read.    
    //my_wav = fopen("/sd/mydir/gp40_48K.wav", "rb");//i think that it is "w" for write, "r"  for read.    
    //my_wav = fopen("/sd/mydir/gp40_48K_quieter.wav", "rb");//i think that it is "w" for write, "r"  for read.    
    //my_wav = fopen("/sd/mydir/gp40_8K.wav","rb");
    my_wav = fopen("/sd/mydir/gp40_8K_2018.wav","rb");
    //my_wav = fopen("/sd/mydir/emd_645.wav", "rb");
    fseek(my_wav, 20, SEEK_SET); // set pointer to byte 20
    fread(&AudioFormat, 2, 1, my_wav); // check file is PCM
    if (AudioFormat==0x01) {
    printf("Wav file is PCM data\n\r");
    }
    else {
    printf("Wav file is not PCM data\n\r");
    }
    
    fseek  (my_wav,20,SEEK_SET);
    fread(&wav_format,sizeof(wav_format),1,my_wav);
    printf("%d  block align\n",wav_format.block_align);
    printf("  %d channels\n",wav_format.num_channels);
    
    
    fseek(my_wav, 36, SEEK_SET);
    fread(&wav_data.subchunk2_ID,4,1,my_wav);
    fseek(my_wav, 40, SEEK_SET);
    fread(&wav_data.subchunk2_size,4,1,my_wav);
    printf("DATA chunck\n");
    printf("  %d subchunk 2 ID\n",wav_data.subchunk2_ID);
    printf("  %d subchunk 2 size\n",wav_data.subchunk2_size);
    i2c.frequency(100000);
    long j = 0;
    printf("set up the codec\n\r");
    while(j <1000){
    wm8731_configTEST();
    j = j + 1;
    }
    //i2s audio data transfer code??
    i2s.stereomono(I2S_STEREO);
    i2s.masterslave(I2S_MASTER);//MASTER definitely works!
    i2s.frequency(sample_freq);
    int yes = i2s.setup_ok();
    pc.printf("Setup went ok?: %d\n", yes);//0  = ack, 1 = Nack*/
    printf("can we get to this point?   1\n\r");
    led3 = 1;
    //myled = 1;
    led2 = 1;
    printf("can we get to this point?   2\n\r");

    myled = 1;
    i2s.start();
    //while (1) {
    fread(&wav_format,sizeof(wav_format),1,my_wav);
    printf("wav_format %d\n\r",wav_format);
       
    fseek(my_wav,20,SEEK_SET);
    fread(&wav_format,sizeof(wav_format),1,my_wav);
    fseek(my_wav,36,SEEK_SET);
    fread(&wav_data,sizeof(wav_data),1,my_wav);
    int num_slices = wav_data.subchunk2_size/wav_format.block_align;
    printf("wav_data.subchunk2_size: %d\n\r",wav_data.subchunk2_size);
    printf("wav_format.block_align: %d\n\r",wav_format.block_align);
    printf("num_slices: %d\n\r",num_slices);
    printf("num_slices*wav_format.block_align %d\n\r",num_slices*wav_format.block_align);
    printf("wav_format.num_channels*wav_format.sig_bps/8: %d\n\r",wav_format.num_channels*wav_format.sig_bps/8);
    printf("chunk_size - sizeof(wav_format) %d\n\r",wav_data.subchunk2_size-sizeof(wav_format));
    printf("sizeof(wav_format): %d\n\r",sizeof(wav_format));
    printf("do we egt to this point:\n\r");
    if (interrupt_condition == 1)
    {
      sampletick.attach(&isr,1.0/16000);  //1/16000
    }       
    slice_buf=(char *)malloc(wav_format.block_align);
    slice = 0;
    while(1){

              while(flag3 == 1)
              {
              //for (slice=0;slice<num_slices;slice+=1) 
              while(slice<num_slices){
                  //t2.start();
          fread(slice_buf,wav_format.block_align,1,my_wav);//THIS IS WHERE HE READS IN THE DATA, TO SLICE_BUF.  BUT USES WAV_FORMAT.BLOCKALIGN AS HIS SIZE GUIDE
          //I do not understand why he is not "seeking" through the file first though...
          if (feof(my_wav)){
            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[1]=0;
          for (channel=0;channel<wav_format.num_channels;channel++) {
            switch (wav_format.sig_bps) {
              case 16:
                //int mybuffer[1];
                //mybuffer[0] = data_sptr[channel];// - 32768;
                if(flag1 == 1)
                {
                   Buffer1[place_hold1] = data_sptr[channel];
                   place_hold1 = place_hold1 + 1; 
                   if(place_hold1 == 8)
                   {
                        flag4 = 1;
                        break;
                    }
                    
                }
                else if(flag2 == 0)
                {
                   Buffer2[place_hold2] = data_sptr[channel];
                   place_hold2 = place_hold2 + 1;
                   if(place_hold2 == 8)
                   {
                        flag4 = 1;
                        break;
                    }                   
                                       
                }
                
                if(interrupt_condition==1)
                {
                    
                    
                }
                else
                {
                    if(verbosity == 1)
                    {
                        t.start();
                        i2s.write(data_sptr,2);
                        t.stop();
                        printf("The time taken was %f seconds\n", t.read());
                        t.reset();      
                    }
                    
                    else
                    {
                        
                       i2s.write(data_sptr,2); 
                        
                    }
                    
                    if(sampling_freq == 48000)
                    {
                    wait_us(0.1);
                     }
                     else if(sampling_freq == 8000)
                     {
                         wait_us(2);
                      }   
                }
                
                
                


                if (verbosity)
                  printf("16 bit channel %d data=%d\n\r ",channel,data_sptr[channel]);
                slice_value[1]+=data_sptr[channel];
                break;
              case 32:
                if (verbosity)
                  printf("32 bit channel %d data=%d ",channel,data_wptr[channel]);
                slice_value[1]+=data_wptr[channel];
                break;
              case 8:
                if (verbosity)
                  printf("8 bit channel %d data=%d ",channel,(int)data_bptr[channel]);
                slice_value[1]+=data_bptr[channel];
                break;
            }
          }
          if(flag4 == 1)
          {
            flag4 = 0;
            break;
            }
          slice_value[1]/=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[1]<<=8;
                        break;
            case 16:    slice_value[1]+=32768;
                        break;
            case 32:    slice_value[1]>>=16;
                        slice_value[1]+=32768;
                        break;
          }
          if (verbosity)
          {
          printf("data_sptr data:  %d \n\r",data_sptr);
          printf("slice_value data:  %d \n\r",slice_value);
          }
        slice = slice + 1;
          //i2s.write(data_sptr,2);
          //t2.stop();
          //printf("The time taken was %f seconds\n", t2.read());
          //t2.reset();
    }
    printf("we must have filled the buffer");
}
}


 /*         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) {
          }
        }*/


    if(interrupt_condition == 1)
    {
        
        sampletick.detach();
    }
        
    i2s.stop();
    
    fclose(my_wav);
    printf("File is now closed.");
    return 0;
    }