led dimming example, dont need to keep all examples, just covering ground to test api

examples/nrf/src/bin/pwm_led.rs

@@ -0,0 +1,47 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use defmt::*;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_nrf::gpio::NoPin;
+use embassy_nrf::pwm::{Prescaler, Pwm};
+use embassy_nrf::Peripherals;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let pwm = Pwm::new(p.PWM0, p.P0_13, NoPin, NoPin, NoPin);
+    // set_period doesnt actually set what you give it, because it only has a
+    // few options from the hardhware so be explicit instead
+    // Div128 is slowest, 125khz still crazy fast for our eyes
+    pwm.set_prescaler(Prescaler::Div128);
+
+    info!("pwm initialized!");
+
+    // default max_duty if not specified is 1000
+    // so 0 would be fully off and 1000 or above would be fully on
+    loop {
+        info!("100%");
+        pwm.set_duty(0, 1000);
+        Timer::after(Duration::from_millis(5000)).await;
+
+        info!("25%");
+        pwm.set_duty(0, 250);
+        Timer::after(Duration::from_millis(5000)).await;
+
+        info!("10%");
+        pwm.set_duty(0, 100);
+        Timer::after(Duration::from_millis(5000)).await;
+
+        info!("5%");
+        pwm.set_duty(0, 50);
+        Timer::after(Duration::from_millis(5000)).await;
+
+        info!("0%");
+        pwm.set_duty(0, 0);
+        Timer::after(Duration::from_millis(5000)).await;
+    }
+}