gpio-pi: Blink example

blink.rs

extern crate gpio_pi;

use std::thread;
use gpio_pi::Gpio;
// use gpio::sys::Gpio;

fn main() {
    let gpio = Gpio::new().unwrap();
    let pinopt = gpio.pin(17);
    let pin = pinopt.output();

    for _ in 0..20 {
        pin.high();
        thread::sleep_ms(600);
        pin.low();
        thread::sleep_ms(600);
    }
}