File content as of revision 0:436ae35cdd94:

/*
Reaction time measurement
Result output to terminal
your result should be about 0.220+-0.060s
best result https://www.youtube.com/watch?v=XsU5AMxvlKg (youtube)
*/
#include "mbed.h"

DigitalOut myled(LED1);             //define LED
DigitalIn mybutton(USER_BUTTON);    //define BUTTON
Timer t;                            //define timer
int x;                              //x for random number storage

int main()
{
    printf("Reaction test!\n");
    printf("Push the button when the LED is on!\n");

    while(1) {

        while(1) {
            
            x=rand()%2000;                  //generate random number 0-2000
            wait_ms(1000+x);                //wait random time between 1 and 3 seconds

            t.start();                      //start the timer

            if(mybutton == 0)break;         //to early for push or cheating
    
            myled=1;                        //LED on
            
            while(1) {                      //wait for push
                if (mybutton == 0)break;    
            }

            t.stop();                       //stop the timer
            
            myled=0;                        //LED off
            
            printf("The time taken was %f seconds\n", t.read());
            
            t.reset();                      //reset the timer
            
            wait(0.5);                      //debounce the BUTTON

        }
        printf("Cheeting!!!\n");    
        wait(0.5);//debounce the BUTTON
    }
}