#![no_std]
#![no_main]

// pick a panicking behavior
use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch panics
                     // use panic_abort as _; // requires nightly
                     // use panic_itm as _; // logs messages over ITM; requires ITM support
                     // use panic_semihosting as _; // logs messages to the host stderr; requires a debugger

use cortex_m::peripheral::{syst, Peripherals};
use cortex_m_rt::entry;

use stm32f3::stm32f303;

#[entry]
fn main() -> ! {
    let cortex_peripherals = Peripherals::take().unwrap();
    let mut systick = cortex_peripherals.SYST;
    systick.set_clock_source(syst::SystClkSource::Core);
    systick.set_reload(8_000_000); // 1s
    systick.clear_current();

    let device_peripherals = stm32f303::Peripherals::take().unwrap();
    let rcc = device_peripherals.RCC;
    rcc.ahbenr().write(|w| w.iopeen().set_bit());
    // PE9: LD3 (red)
    // PE8: LD4 (blue)
    // PE10: LD5 (orange)
    let gpioe = device_peripherals.GPIOE;
    gpioe
        .moder()
        .write(|w| w.moder9().output().moder8().output().moder10().output());
    gpioe.bsrr().write(|w| w.bs9().set_bit());
    gpioe.bsrr().write(|w| w.bs8().set_bit());
    gpioe.bsrr().write(|w| w.bs10().set_bit());

    systick.enable_counter();
    let mut enabled = true;
    loop {
        while !systick.has_wrapped() {}
        enabled = !enabled;
        gpioe.odr().write(|w| {
            w.odr8()
                .bit(enabled)
                .odr9()
                .bit(enabled)
                .odr10()
                .bit(enabled)
        });
    }
}