rtic_blinky_stm32f2

// run with gdb, either from terminal or in vscode
//
// from terminal:
// start openocd in separate terminal
// > openocd -f openocd.cfg
//
// start gdb
// > arm-none-eabi-gdb target/thumbv7em-none-eabihf/debug/examples/rtic_blinky -x openocd.gdb

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

use panic_semihosting as _;

#[rtic::app(device = stm32f2xx_hal::stm32, dispatchers = [EXTI0], peripherals = true)]
mod app {
    use cortex_m_semihosting::hprintln;
    use dwt_systick_monotonic::DwtSystick;
    use rtic::time::{duration::Seconds};

    const MONO_HZ: u32 = 8_000_000; // 8 MHz

    #[monotonic(binds = SysTick, default = true)]
    type MyMono = DwtSystick<MONO_HZ>;

    #[shared]
    struct Shared {
        gpioa: stm32f2xx_hal::stm32::GPIOA,
        toggle: bool,
    }

    #[local]
    struct Local {}

    #[init]
    fn init(cx: init::Context) -> (Shared, Local, init::Monotonics) {
        let mut dcb = cx.core.DCB;
        let dwt = cx.core.DWT;
        let systick = cx.core.SYST;

        let mono = DwtSystick::new(&mut dcb, dwt, systick, 8_000_000); // maybe MONO_HZ?

        let device = cx.device;

        // power on GPIOA, RM0368 6.3.11
        device.RCC.ahb1enr.modify(|_, w| w.gpioaen().set_bit());
        // configure PA5 as output, RM0368 8.4.1
        device.GPIOA.moder.modify(|_, w| w.moder5().bits(1));

        hprintln!("init").ok();

        // Schedule `toggle` to run 8e6 cycles (clock cycles) in the future
        toggle::spawn_after(Seconds(1u32)).ok();

        (
            Shared {
                gpioa: device.GPIOA,
                toggle: false,
            },
            Local {},
            init::Monotonics(mono),
        )
    }

    #[task(shared = [toggle, gpioa])]
    fn toggle(cx: toggle::Context) {
        let toggle = cx.shared.toggle;
        let gpioa = cx.shared.gpioa;



        (toggle, gpioa).lock(|toggle, gpioa| {
            hprintln!("toggle: {}  @ !", toggle).unwrap();

            if *toggle {
                gpioa.bsrr.write(|w| w.bs5().set_bit());
            } else {
                gpioa.bsrr.write(|w| w.br5().set_bit());
            }

            *toggle = !*toggle;
        });
        toggle::spawn_after(Seconds(1u32)).ok();
    }
}