Random Led

#include "mbed.h"

Serial pc( USBTX, USBRX );

int main()
{
    pc.baud( 115200 );
    DigitalOut leds[] = {PTC0, PTC1, PTC2, PTC3, PTC4, PTC5, PTC7, PTC8};
    float brightness[] = {0, 0.25, 0.50, 1, 0.50, 0.25, 0, 0};
    float T = 15;
    DigitalIn btn_left( PTC9 );
    DigitalIn btn_right( PTC10 );
    DigitalIn speed_down( PTC11 );
    DigitalIn speed_up( PTC12 );
    bool speed_down_pressed = false;
    bool speed_up_pressed = false;
    int direction = 1;
    int speed = 25;
    long long counter = 0;

    while(1) {
        for(float i = 0; i < T; i+=1) {
            for(int j = 0; j < 8; j++) {
                if(i < (T * brightness[j])) {
                    leds[j] = true;
                } else {
                    leds[j] = false;
                }
            }
            wait_ms(1);
        }

        if(counter % speed == 0) {
            if(direction == -1) {
                float tmp = brightness[0];
                for(int i = 0; i < 7; i++) {
                    brightness[i] = brightness[i + 1];
                }
                brightness[7] = tmp;
            } else if(direction == 1) {
                float tmp = brightness[7];
                for(int i = 7; i > 0; i--) {
                    brightness[i] = brightness[i - 1];
                }
                brightness[0] = tmp;
            }

        }

        if(!btn_left) {
            direction = -1;
        }
        if(!btn_right) {
            direction = 1;
        }
        if(!speed_up) {
            speed_up_pressed = true;
        }
        if(!speed_down) {
            speed_down_pressed = true;
        }

        if(counter % 20 == 0) {
            if(speed_up_pressed) {
                speed--;
                speed_up_pressed = false;
            }
            if(speed_down_pressed) {
                speed++;
                speed_down_pressed = false;
            }
        }

        counter++;
    }
}