refactor: use a proper delay instead of a useless for loop

It blinks every 500ms or so!

Cargo.lock

@@ -123,6 +123,7 @@ checksum = "8d5439c4ad607c3c23abf66de8c8bf57ba8adcd1f129e699851a6e43935d339d"
 name = "nucleo-l053r8-blink"
 version = "0.1.0"
 dependencies = [
+ "cortex-m",
  "cortex-m-rt",
  "panic-halt",
  "stm32l0xx-hal",

Cargo.toml

@@ -5,6 +5,7 @@ edition = "2024"
 
 
 [dependencies]
+cortex-m = "0.7.7"
 cortex-m-rt = "0.7.5"
 panic-halt = "1.0.0"
 stm32l0xx-hal = { version = "0.10.0", features = [

src/main.rs

@@ -1,4 +1,3 @@
-#![deny(unsafe_code)]
 #![no_main]
 #![no_std]
 
@@ -10,6 +9,7 @@ use stm32l0xx_hal::{pac, prelude::*, rcc::Config};
 #[entry]
 fn main() -> ! {
     let dp = pac::Peripherals::take().unwrap();
+    let cp = cortex_m::Peripherals::take().unwrap();
 
     // Configure the clock.
     let mut rcc = dp.RCC.freeze(Config::hsi16());
@@ -21,15 +21,14 @@ fn main() -> ! {
     // Configure PA1 as output.
     let mut led = gpioa.pa5.into_push_pull_output();
 
-    loop {
-        // Set the LED high one million times in a row.
-        for _ in 0..1_000_000 {
-            led.set_high().unwrap();
-        }
+    // Get the delay provider.
+    let mut delay = cp.SYST.delay(rcc.clocks);
 
-        // Set the LED low one million times in a row.
-        for _ in 0..1_000_000 {
-            led.set_low().unwrap();
-        }
+    loop {
+        led.set_high().unwrap();
+        delay.delay_ms(500_u16);
+
+        led.set_low().unwrap();
+        delay.delay_ms(500_u16);
     }
 }