// pwm_blinkled.rs - Blinks an LED using hardware PWM.
//
// Remember to add a resistor of an appropriate value in series, to prevent
// exceeding the maximum current rating of the GPIO pin and the LED.
//
// Interrupting the process by pressing Ctrl-C causes the application to exit
// immediately without disabling the PWM channel. Check out the
// gpio_blinkled_signals.rs example to learn how to properly handle incoming
// signals to prevent an abnormal termination.

use std::error::Error;
use std::thread;
use std::time::Duration;

use rppal::pwm::{Channel, Polarity, Pwm};

fn main() -> Result<(), Box<dyn Error>> {
    // Enable PWM channel 0 (BCM GPIO 18, physical pin 12) at 2 Hz with a 25% duty cycle.
    let pwm = Pwm::with_frequency(Channel::Pwm0, 2.0, 0.25, Polarity::Normal, true)?;

    // Sleep for 2 seconds while the LED blinks.
    thread::sleep(Duration::from_secs(2));

    // Reconfigure the PWM channel for an 8 Hz frequency, 50% duty cycle.
    pwm.set_frequency(8.0, 0.5)?;

    thread::sleep(Duration::from_secs(3));

    Ok(())

    // When the pwm variable goes out of scope, the PWM channel is automatically disabled.
    // You can manually disable the channel by calling the Pwm::disable() method.
}