File content as of revision 0:86aaef96170e:

#include "mbed.h"
#include "MODSERIAL.h"

DigitalOut led(LED_GREEN);
DigitalIn button(PTA4);
MODSERIAL pc(USBTX, USBRX);

const int baudrate = 115200;
const int ms_wait = 100;

const float period_led = 0.1;
const float t_on = 0.1;
const float t_off = period_led - t_on;

const int led_on = 0;
const int led_off = 1;

const int button_pressed = 0;


void blink(int number_of_blinks)
{
    for(int i = 0; i < 5 ; i++) {
        led.write(led_on); //turn led on
        wait(t_on);
        led.write(led_off); // toggle led
        wait(t_off);
    }
}

int main()
{
    int waittime = 0;
    led.write(led_off);
    pc.baud(baudrate);
    pc.printf("Hello World!\n");
    
    while (true) {
        wait_ms(ms_wait); //const value
        if(button.read() == button_pressed) //button pressed
        {
            waittime++;
            pc.printf("Pressed for %d ms\n", waittime * ms_wait);  //const used again -> updating it at the top gives consistent results!!
        }
        else //button released
        {
            waittime = 0;
        }
        if(pc.readable()) //if character available. If expresseion is non-zero, it's true
        {
            pc.rxBufferFlush();    //flush the buffer. Otherwise pc.readable() will stay larger than zero
            blink(1);
        }
    }
}