rtfm-blinky systick

examples/rtfm-blinky.rs

+#![feature(proc_macro)]
+#![deny(unsafe_code)]
+// #![deny(warnings)]
+#![no_std]
+
+extern crate cortex_m;
+extern crate cortex_m_rtfm as rtfm;
+extern crate stm32f4x_hal as hal;
+
+use hal::gpio::gpioa::PA5;
+use hal::gpio::{Output, PushPull};
+use hal::prelude::*;
+use hal::stm32f4x;
+use hal::timer::{Event, Timer};
+use rtfm::{app, Threshold};
+
+app! {
+    device: stm32f4x,
+
+    resources: {
+        static LED: PA5<Output<PushPull>>;
+    },
+
+    tasks: {
+        SYS_TICK: {
+            path: sys_tick,
+            resources: [LED],
+        },
+    }
+}
+
+fn init(p: init::Peripherals) -> init::LateResources {
+    let mut flash = p.device.FLASH.constrain();
+    let mut rcc = p.device.RCC.constrain();
+
+    let clocks = rcc.cfgr.freeze(&mut flash.acr);
+    let mut gpioa = p.device.GPIOA.split(&mut rcc.ahb1);
+
+    let led = gpioa
+        .pa5
+        .into_push_pull_output(&mut gpioa.moder, &mut gpioa.otyper);
+
+    Timer::syst(p.core.SYST, 1.hz(), clocks).listen(Event::TimeOut);
+
+    init::LateResources { LED: led }
+}
+
+fn idle() -> ! {
+    loop {
+        rtfm::wfi();
+    }
+}
+
+fn sys_tick(_t: &mut Threshold, mut r: SYS_TICK::Resources) {
+    if r.LED.is_low() {
+        r.LED.set_high()
+    } else {
+        r.LED.set_low()
+    }
+}