File content as of revision 1:78ca0566c062:

#include "mbed.h"
#include "max32630fthr.h"
#include "USBSerial.h"
#include "stdio.h"
#include "SDFileSystem.h"

//still needs BITS PER SAMPLE PARSING.
//do this like so: PWM.write(WavValue/2^BPS)

#define BUFFER_SIZE 128
#define HALF_BUFFER 64

DigitalOut rLED(LED1);
DigitalOut gLED(LED2);
DigitalOut bLED(LED3);

DigitalIn Button(P2_3);

MAX32630FTHR pegasus(MAX32630FTHR::VIO_3V3);
PwmOut PWM(P5_6);
AnalogIn POT(AIN_0);
volatile int bufferPOS = 0;
volatile unsigned int g=0;

Serial daplink(P2_1,P2_0);
USBSerial microUSB;
SDFileSystem sd(P0_5, P0_6, P0_4, P0_7, "sd");

float audioDataBuffer[BUFFER_SIZE];

struct WavFile
{
    long int size;
    int channels;
    int sampleRate;
    int bitsPerSample;
};

float potval,reading;

void placeNewSample(void)
{
    PWM.write(audioDataBuffer[bufferPOS++]*!Button); //multiply by POT value for volume.
    bufferPOS = (bufferPOS+1) & 0x07F;
}

int main()
{   
    WavFile Track;
    Ticker SampleTime;
    
    daplink.printf("\f---DAPLINK SERIAL PORT---\r\n\r\nPLAY TONE VER 26 \r\n (CHANGEABLE TONE) MAX FREQUENCY: 1680. \r\n AFTER 1680Hz INPUTS CANNOT BE PROCESSED.\r\n\r\n");
    microUSB.printf("micro USB serial port\r\n");
    rLED = LED_ON;
    wait_ms(500);
    rLED = LED_OFF;
    gLED = LED_ON;
    wait_ms(500);
    bLED = LED_ON;
    gLED = LED_OFF;
    
    printf("Generating sine...\r\n");
    int i;
    for(i=0; i<128;i++)
    {
        audioDataBuffer[i] =((1.0 + sin((double(i)/16.0*6.28318530717959)))/2.0); //formula copied from mbed example
    }
    
    printf("Playing tone...\r\n");
    
    int PlayingFreq = 500;
    
    while(1)
    {
    
        Track.sampleRate = PlayingFreq * 16; //TONE FREQ = SAMPLE RATE / SAMPLES PER CYCLE
        
        PWM.period_us(1); //1MHz
        
        float ticker_period = (float) 1/(Track.sampleRate);
        
        printf("\r\nTicker Period: %f\tTicker Freq: %f\r\nTarget Freq: %i\r\n\r\n",ticker_period, 1/ticker_period, PlayingFreq);

        SampleTime.attach(&placeNewSample,ticker_period);
        bLED = LED_OFF;
        
        char c;
        char number[10];
        for(i=0;i<10 && c != '\r' && c != '\n'; i++)
        {
               c = daplink.getc();
               number[i] = c;
        }
        
        gLED = LED_ON;
        PlayingFreq = strtol(number,NULL,0);
        gLED = LED_OFF;
        rLED = !rLED;
        SampleTime.detach();
    }
};