DE2-115 Will Not Output Audio

I am trying to output audio from the DE2-115 board. I have the audio and the external clock in my .qsys file, and I have been using the example C code given by the Audio core documentation. I want to create a specific tone held in an array named c, and output it to the board. I am able to open the audio device, but the code does not seem to be able to write the data to the left and right buffers. Is there a way to do this?

Here is my code:

alt_up_audio_dev * audio_dev;

/* used for audio record/playback */

unsigned int l_buf;

unsigned int r_buf;

// open the Audio port

audio_dev = alt_up_audio_open_dev ("/dev/audio_0");

if ( audio_dev == NULL)

alt_printf ("Error: could not open audio device \n");

else

alt_printf ("Opened audio device \n");

/* read and echo audio data */

alt_up_audio_reset_audio_core(audio_dev);

int count = 0;

while(1)

{

// write audio buffer

int sound_size = 50;

int r_size = alt_up_audio_write_fifo_space(audio_dev, ALT_UP_AUDIO_RIGHT);

int l_size = alt_up_audio_write_fifo_space(audio_dev, ALT_UP_AUDIO_LEFT);

if((r_size > sound_size) && (l_size > sound_size)){

alt_up_audio_write_fifo_head(audio_dev, c, ALT_UP_AUDIO_RIGHT);//write the contents of the tone array to right buffer

alt_up_audio_write_fifo_head(audio_dev, c, ALT_UP_AUDIO_LEFT);

}

}

}

Sidebar: Should the audio be memory-mapped or streaming if I already have the arrays written somewhere and I just want to output them?