stm32l0xx-hal 0.3.0

//! Real-time clock (RTC) example
//!
//! This example initializes the RTC with a specific time and prints this time
//! to the USART. You should see this time counting up, even if you reset the
//! device, or hold it in reset for a while.
//!
//! If you disconnect the device from power, the RTC should reset to the initial
//! time programmed here after you connect it again. If you press the button,
//! that should rapidly change the seconds while you hold it down.


#![no_main]
#![no_std]


extern crate panic_semihosting;


use core::fmt::Write;

use cortex_m_rt::entry;
use stm32l0xx_hal::{
    prelude::*,
    pac,
    pwr::PWR,
    rcc,
    rtc::{
        Instant,
        RTC,
    },
    serial,
};


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

    let mut rcc   = dp.RCC.freeze(rcc::Config::hsi16());
    let mut pwr   = PWR::new(dp.PWR, &mut rcc);
    let     gpioa = dp.GPIOA.split(&mut rcc);
    let     gpiob = dp.GPIOB.split(&mut rcc);

    let button = gpiob.pb2.into_floating_input();

    let serial = dp.USART2
        .usart(
            (gpioa.pa2, gpioa.pa3),
            serial::Config::default()
                .baudrate(115_200.bps()),
            &mut rcc,
        )
        .unwrap();
    let (mut tx, _) = serial.split();

    let instant = Instant::new()
        .set_year(19)
        .set_month(8)
        .set_day(9)
        .set_hour(13)
        .set_minute(36)
        .set_second(0);

    let mut rtc = RTC::new(
        dp.RTC,
        &mut rcc,
        &mut pwr,
        instant,
    );

    loop {
        let mut instant = rtc.now();

        if button.is_low().unwrap() {
            let second = instant.second() + 1;

            instant = if second < 60 {
                instant.set_second(second)
            }
            else {
                instant.set_second(0)
            };

            rtc.set(instant);
        }

        write!(
            tx,
            "20{:02}-{:02}-{:02} {:02}:{:02}:{:02}\r\n",
            instant.year(),
            instant.month(),
            instant.day(),
            instant.hour(),
            instant.minute(),
            instant.second(),
        )
        .unwrap();
    }
}