File content as of revision 0:213bf9be9e9e:

#include "mbed.h"

// Blinky
DigitalOut led(LED1);

Serial pc(p9, p10); // tx, rx

// Our sensor as an InterruptIn
InterruptIn sensor(D0);

// Grove Earbud Sensor include
#include "GroveEarbudSensor.h"

// callback for receiving heartrate values
void heartrateCallback(float heartrate,void *data) {
    printf("Callback: heartrate = %.1f\r\n",heartrate);
}

int main()
{  
/* 
    // announce
    printf("Grove Earbud Sensor Example v1.0.0\r\n");
    
    // allocate the earbud sensor
    printf("Allocating earbud sensor instance...\r\n");
    GroveEarbudSensor earbud(&sensor); 
    
    // register our callback function
    printf("registering callback...\r\n");
    earbud.registerCallback(heartrateCallback);
    
    // begin main loop
    printf("Beginning main loop...\r\n");
    while (true) {
        // blink... 
        led = !led; 
        wait(0.5);
        
        // we can also call directly 
        //printf("Direct: heartrate = %.1f\r\n",earbud.getHeartRate());
    }*/
       /* pc.baud(19200);
        pc.printf("Hello World\n");*/
        
        // announce
    printf("Grove Earbud Sensor Example v1.0.0\r\n");
    
    // allocate the earbud sensor
    printf("Allocating earbud sensor instance...\r\n");
    GroveEarbudSensor earbud(&sensor); 
    
    // register our callback function
    printf("registering callback...\r\n");
    earbud.registerCallback(heartrateCallback);
    
    // begin main loop
    printf("Beginning main loop...\r\n");
    while (true) {
        // blink... 
        led = !led; 
        wait(0.5);
        
        // we can also call directly 
        //printf("Direct: heartrate = %.1f\r\n",earbud.getHeartRate());
    }
}