///////////////////////////////////
//
// program_10 project
//
// created 7/13/21 by tj
// rev 0
//
///////////////////////////////////
//
// Use PWM to generate notes for duration
//
// .
//
///////////////////////////////////

#include "mbed.h"
#include <stdio.h>

#define DUTY 0.5        // 50%
#define T_WAIT 5000000   // in us - 0.5s

// function prototypes
void get_input(int * freq, int * length);
void output_note(int per, int length);

// Global HARDWARE Objects
// Create a PWM object to drive pin D7
PwmOut Audio_Out(D7);

int main(void){
    setbuf(stdout, NULL);
    
    // splash 
    printf("program_10 - example for EE2905\n");
    printf("Using Mbed OS version %d.%d.%d\n\n", 
            MBED_MAJOR_VERSION, MBED_MINOR_VERSION, MBED_PATCH_VERSION);

    // working variables
    int frequency;  // hz
    int period;     // us
    int duration;   // ms
    
    // setup PWM
    Audio_Out.write(DUTY);

    // continuously check the reostat and update the PWM
    while(1){
        // get input
        get_input(&frequency, &duration);
        
        // convert freq to period in us
        period = 1000000/frequency;
        
        //update the PWM
        output_note(period, duration);
    }// end while
    
    return 0;
}// end main

void get_input(int * freq, int * length){
    // get values
    printf("Please enter a frequency in Hz and a duration in us: ");
    scanf("%i %i", freq, length);
    
    return;
}// end get_input

void output_note(int per, int length){
    Audio_Out.resume();
    Audio_Out.period_us(per);
    wait_us(length);
    Audio_Out.suspend();
    
    return;
}// end output_note