stm32f4disc-demo/src/main.rs

#![deny(unsafe_code)]
#![deny(warnings)]
#![no_main]
#![no_std]

extern crate panic_semihosting;

//use cortex_m_semihosting::hprintln;
use hal::gpio::{ExtiPin, Output, PushPull};
use hal::prelude::*;
use rtfm::app;

type Led = hal::gpio::gpiod::PD<Output<PushPull>>;

const PERIOD: u32 = 8_000_000;

#[app(device = hal::stm32)]
const APP: () = {
    static mut index: usize = ();
    static mut leds: [Led; 4] = ();

    #[init(spawn = [switch_leds])]
    fn init() -> init::LateResources {
        // Set up the LEDs and spawn the LEDs switch task.
        let gpiod = device.GPIOD.split();
        let leds = [
            gpiod.pd12.into_push_pull_output().downgrade(),
            gpiod.pd13.into_push_pull_output().downgrade(),
            gpiod.pd14.into_push_pull_output().downgrade(),
            gpiod.pd15.into_push_pull_output().downgrade(),
        ];
        spawn.switch_leds().unwrap();


        init::LateResources { index: 0, leds }
    }

    #[task(schedule = [switch_leds], resources = [index, leds])]
    fn switch_leds() {
        let index = *resources.index;
        let num_leds = resources.leds.len();
        resources.leds[index].set_high();
        resources.leds[(index + 2) % num_leds].set_low();
        *resources.index = (index + 1) % 4;

        schedule.switch_leds(scheduled + PERIOD.cycles()).unwrap();
    }

    extern "C" {
        fn UART4();
    }
};