Code to make an LED (on PA5) blink on a STM32L476RGTx using timer interrupts.

led_blink_timer_interrupt.rs

#![no_main]
#![no_std]
#![feature(type_alias_impl_trait)]

use hal;
use hal::clocks::Clocks;
use hal::gpio::Pin;
use hal::{
    gpio::{PinMode, Port},
    pac::TIM5,
    timer::{Timer, TimerInterrupt},
};
use panic_halt as _;
use rtic::app;

#[app(device = hal::pac, peripherals = true)]
mod app {
    use cortex_m::asm;

    use super::*;

    #[shared]
    struct Shared {}

    #[local]
    struct Local {
        led: Pin,
        led_timer: Timer<TIM5>,
    }

    #[init]
    fn init(cx: init::Context) -> (Shared, Local) {
        // let dp = pac::Peripherals::take().unwrap();
        let dp = cx.device;
        let clock_cfg = Clocks::default();
        clock_cfg.setup().unwrap();

        let led = Pin::new(Port::A, 5, PinMode::Output);

        let mut timer = Timer::new_tim5(dp.TIM5, 2., Default::default(), &clock_cfg);
        timer.enable_interrupt(TimerInterrupt::Update);
        timer.enable();

        (
            Shared {},
            Local {
                led_timer: timer,
                led,
            },
        )
    }

    #[idle()]
    fn idle(_: idle::Context) -> ! {
        loop {
            asm::nop();
        }
    }

    #[task(binds = TIM5, local = [led_timer, led], priority = 1)]
    fn blink_led(cx: blink_led::Context) {
        cx.local.led_timer.clear_interrupt(TimerInterrupt::Update);
        cx.local.led.toggle();
    }
}