How to make Knight Rider with STM32F411 on Mbed

1#include "mbed.h"
2
3BusOut leds(PC_8,PC_6,PC_5,PA_12,PA_11,PB_12,PB_2,PB_1);
4
5int  ms=100;
6
7int main(){
8    while(1){
9        for(int i=0; i<=7; i++){
10            leds[i]=1;
11            wait_ms(ms);
12            leds[i]=0;
13            }
14             for(int i=7; i>=0; i--){
15            leds[i]=1;
16            wait_ms(ms);
17            leds[i]=0;
18            }
19        }
20    }