Replace spinlock with thread::sleep; print timings

examples/src/bin/moving-pixel.rs

@@ -3,6 +3,9 @@
 //! with DIN-Pin. You just need DIN pin, no clock. WS2818 uses one-wire-protocol.
 //! See the specification for details
 
+use std::ops::Add;
+use std::time::{Duration, Instant};
+use std::thread;
 use ws2818_examples::{get_led_num_from_args, sleep_busy_waiting_ms};
 use ws2818_rgb_led_spi_driver::adapter_gen::WS28xxAdapter;
 use ws2818_rgb_led_spi_driver::adapter_spi::WS28xxSpiAdapter;
@@ -31,6 +34,28 @@ fn main() {
         adapter.write_encoded_rgb(&data).unwrap();
 
         i = (i + 1) % num_leds;
-        sleep_busy_waiting_ms(1000 / 10); // 100ms / 10Hz
+        let ms = 1000 / 10; // 100ms / 10Hz
+        let before = Instant::now(); // For printing time this takes
+
+        // Using thread::sleep() - DOES NOT WORK - lights turn solid white
+        thread::sleep(Duration::from_millis(ms));
+
+        // Original code - WORKS FINE
+        /*
+        let target_time = Instant::now().add(Duration::from_millis(ms));
+        loop {
+            if Instant::now() >= target_time {
+                break;
+            }
+        }
+        */
+
+        let after = Instant::now();
+
+        // With original code:
+        //     100.0010 to 100.0025 (about 1 to 2.5 microseconds extra)
+        // With thread::sleep
+        //     100.09 to 100.1 (about 90-100 microseconds extra)
+        println!("{:?}", after - before);
     }
 }