Rust STM32f103c8 external interrupt demo

ext.rs

#![no_std]
#![no_main]

use panic_halt;
use cortex_m::asm::delay;
use cortex_m_rt::entry; // The runtime
use embedded_hal::digital::v2::OutputPin; // the `set_high/low`function

use stm32f1xx_hal::{delay::Delay, pac, prelude::*}; // STM32F1 specific functions
use stm32f1xx_hal::usb::{Peripheral, UsbBus};
use stm32f1xx_hal::pac::{Interrupt};
use stm32f1xx_hal::{stm32};
use stm32f1xx_hal::pac::interrupt;
use stm32f1xx_hal::gpio::*;

use core::panic::PanicInfo;
use core::mem::MaybeUninit;

static mut LED: MaybeUninit<stm32f1xx_hal::gpio::gpioc::PC13<Output<PushPull>>> = MaybeUninit::uninit();
static mut INT_PIN: MaybeUninit<stm32f1xx_hal::gpio::gpioa::PA7<Input<Floating>>> = MaybeUninit::uninit();

#[interrupt]
fn EXTI9_5() {
    let led = unsafe { &mut *LED.as_mut_ptr() };
    let int_pin = unsafe { &mut *INT_PIN.as_mut_ptr() };

    if int_pin.check_interrupt() {
        led.toggle();

        // if we don't clear this bit, the ISR would trigger indefinitely
        int_pin.clear_interrupt_pending_bit();
    }
}



#[entry]
fn main() -> ! {
    
    let mut dp = pac::Peripherals::take().unwrap();
    let cp = cortex_m::Peripherals::take().unwrap();

    let mut rcc = dp.RCC.constrain();
    let mut gpioa = dp.GPIOA.split(&mut rcc.apb2);
    let mut gpiob = dp.GPIOB.split(&mut rcc.apb2);
    let mut gpioc = dp.GPIOC.split(&mut rcc.apb2);
    let mut flash = dp.FLASH.constrain();

    // let mut led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);

    // let mut led_but = gpiob.pb5.into_push_pull_output(&mut gpiob.crl);
    // led_but.set_high().ok();
    let mut afio = dp.AFIO.constrain(&mut rcc.apb2);
   
    let led = unsafe { &mut *LED.as_mut_ptr() };
    *led = gpioc.pc13.into_push_pull_output(&mut gpioc.crh);

    let int_pin = unsafe { &mut *INT_PIN.as_mut_ptr() };
    *int_pin = gpioa.pa7.into_floating_input(&mut gpioa.crl);
    int_pin.make_interrupt_source(&mut afio);
    int_pin.trigger_on_edge(&mut dp.EXTI, Edge::RISING_FALLING);
    int_pin.enable_interrupt(&mut dp.EXTI);

    let clocks = rcc
        .cfgr
        .use_hse(8.mhz())
        .sysclk(48.mhz())
        .pclk1(24.mhz())
        .freeze(&mut flash.acr);
    
    
    unsafe {
        pac::NVIC::unmask(pac::Interrupt::EXTI9_5);
    }


    loop {

    }

}