File content as of revision 2:d0b2bfd92a6b:

#include "mbed.h"

DigitalOut myled1(LED1);
DigitalOut myled2(LED2);
DigitalOut myled3(LED3);
DigitalOut myled4(LED4);

DigitalIn down(p12);
DigitalIn left(p13);
DigitalIn up(p15);
DigitalIn right(p16);

Serial xbee(p9,p10);
int main() {
    xbee.baud(57600);
    while(1) {
        if(up&&!left&&!right){
            myled1 = 1;
            xbee.putc(0);
        }
        if(up&&right){
            myled1=1;
            myled2=1;
        }
        if(right&&!up&&!down){
            myled2 = 1;
        }
        if(down&&right){
            myled2=1;
            myled3=1;
        }
        if(down&&!left&&!right){
            myled3 = 1;
        }
        if(down&&left){
            myled3=1;
            myled4=1;
        }
        if(left&&!up&&!down){
            myled4 = 1;
        }
        if(up&&left){
            myled1=1;
            myled4=1;
        }
        myled1=0;
        myled2=0;
        myled3=0;
        myled4=0;
    }
}