#include "mbed.h"
Serial pc(USBTX, USBRX); // tx, rx
PwmOut led(LED1);
int main() {
    char c; 
    float brightness = 1.0;
    pc.printf("Press 'u' para aumentar brilho e 'd' para diminuir \n\r");
    while(1) {
        c = pc.getc();
        if((c == 'u') && (brightness > 0.0)) {
            brightness -= 0.1;
            led = brightness;
        }
        if((c == 'd') && (brightness < 1.0)) {
            brightness += 0.1;
            led = brightness;
        } 
        pc.printf("Brilho  = %2.0f %% \r", (1.0-led)*100);
     }
}