gistfile1.txt

#![no_std]
#![no_main]

use panic_halt as _;
use stm32ral::{gpio, read_reg, write_reg};

#[cortex_m_rt::entry]
fn main() -> ! {
    //critical_section::with(|_| {
    cortex_m::interrupt::free(|_| {
        unsafe {
            if(read_reg!(gpio, GPIOA, IDR) == 1) {
                write_reg!(gpio, GPIOA, ODR, 1);
            } else {
                write_reg!(gpio, GPIOA, ODR, 2);
            }
        }
    });
    loop {}
}