Initial commit

src/main.rs

@@ -0,0 +1,63 @@
+#![no_std]
+#![no_main]
+use cortex_m::peripheral::{syst, Peripherals};
+use cortex_m_rt::{entry, exception};
+use cortex_m_semihosting::hprintln;
+
+use embedded_hal::digital::v2::OutputPin;
+use nrf52832_hal as hal;
+use nrf52832_hal::gpio::Level;
+
+use panic_semihosting as _;
+
+const F_CPU:u32 = 64_000_000;
+
+static mut FIRE_1S:bool = false;
+
+#[entry]
+fn main() -> ! {
+    hprintln!("Hello, world!").unwrap();
+
+    let peripherals = Peripherals::take().unwrap();
+    let mut systick = peripherals.SYST;
+    systick.set_clock_source(syst::SystClkSource::Core);
+    systick.set_reload(F_CPU / 1000 - 1);
+    systick.clear_current();
+    systick.enable_interrupt();
+    systick.enable_counter();
+
+    let p = hal::pac::Peripherals::take().unwrap();
+    let port0 = hal::gpio::p0::Parts::new(p.P0);
+    let mut led = port0.p0_17.into_push_pull_output(Level::Low);
+    led.set_low().unwrap();
+
+    let mut state:bool = false;
+    loop {
+        unsafe {
+            if FIRE_1S {
+                FIRE_1S = false;
+                if state {
+                    hprintln!("off").unwrap();
+                    led.set_low().unwrap();
+                    state = false;
+                } else {
+                    hprintln!("on").unwrap();
+                    led.set_high().unwrap();
+                    state = true;
+                }
+            }
+        }
+    }
+}
+
+#[exception]
+fn SysTick() {
+    static mut CNT:u32 = 0;
+    *CNT += 1;
+    if *CNT == 1000 {
+        *CNT = 0;
+        unsafe {
+            FIRE_1S = true;
+        }
+    }
+}