rust blue pill access GPIO with stm32f1 PAC

blue_pill_pac.rs

#![no_std]
#![cfg_attr(not(doc), no_main)]

//use panic_rtt_target as _;
use panic_halt as _;

use cortex_m_rt::entry;
//use core::ptr;

use stm32f1::stm32f103;



#[entry]
fn main() -> ! {
    let mut peripherals = stm32f103::Peripherals::take().unwrap();
    

   
    


    // // Set up named variables for the register addresses we'll use. These are defined in the STM32's
    // // reference manual (RM): rm0008. You can find base addresses under the Memory and bus architecture chapter, and the offsets (Things we | the base addresses with), under the RCC and GPIO chapters, registers sections.

    // let RCC_AHB2ENR = 0x4002_1000 | 0x18;
    // let GPIOC_BASE = 0x4001_1000;
    let gpioc = &peripherals.GPIOC;
    let rcc = &peripherals.RCC;

    // // You can find these offsets under each RM register table: `Address Offset`
    // let GPIOC_CRH = GPIOC_BASE | 0x04;
    // let GPIOC_BSRR = GPIOC_BASE | 0x10;
    

    // let gpioaen_field = 4;
    // let output_pin_num = 13;  // A variable to indicate with GPIO pin number we're using. Ie PC13
    

    // unsafe {
    //     // Set the GPIOCEN field of the RCC register block, AHB2_ENR register. This enables the peripheral clock
    //     // to all pins on the GPIOC port.
    //     ptr::write_volatile(RCC_AHB2ENR as *mut u32, 1 << gpioaen_field);
    rcc.apb2enr.write(|w| w.iopcen().set_bit());

    //     // Set the mode of PC13 to Output, The hex values 0b01 is defined in the GPIO registers section of the RM
    //     // We Multiply the pin numbers by 4, since each field of this register is 4 bits wide. Also note that we  perform a register read, as not to override previous settings. 

    //     let mut existing_val = ptr::read_volatile(GPIOC_CRH as *const u32);
    //     // We use binary arithmetic here to 0 out the fields we’ll write to. Modifying single-bit fields is simpler.
    //     existing_val = existing_val & !(0b1111 <<  ((output_pin_num -8) * 4) );  //-8 being the offset for CRH register

    //     ptr::write_volatile(
    //         GPIOC_CRH as *mut u32, 
    //         existing_val | (0b0001 << ((output_pin_num -8) * 4) )  // output mode @ 10MHz max speed; general purpose push-pull
    //     );
    gpioc.crh.write(|w| {
        w.mode13().bits(0b11);
        w.cnf13().bits(0b00)
    });
    //     // check schematic for this bit inverse

    //     // light up LED; RESET PC13 (0V)
    //     ptr::write_volatile(GPIOC_BSRR as *mut u32, 1 << (output_pin_num + 16));
        
    gpioc.bsrr.write(|w| w.br13().set_bit());

        
    //     // turn off LED; SET PC13 (3.3V)
    //     //ptr::write_volatile(GPIOC_BSRR as *mut u32, 1 << (output_pin_num));


    // }
    loop {}
}