path: root/src/main.rs

#![no_std]
#![feature(asm)]

#[macro_use] extern crate stm32f103xx;
extern crate cortex_m;

use stm32f103xx::{GPIOA, GPIOB, RCC, SYST, I2C1, EXTI, NVIC, Interrupt, AFIO, Peripherals};
use stm32f103xx::{gpioa};
use cortex_m::peripheral::SystClkSource;

mod mutex;
mod i2c;
mod ds3231;
mod at24c;

const SYNC_PERIOD: u8 = 10;

struct ShiftRegister<'a> {
    gpioa: &'a gpioa::RegisterBlock,
    width: u8,
}

struct Clock {
    sec: u8,
    min: u8,
    hr: u8,
    reset: u8
}

struct GlobalState {
    disp: Option<ShiftRegister<'static>>,
    i2c: Option<i2c::I2C<'static>>,
    i2c_inited: bool,
    buff: [u8; 6],
    time: Clock,
    perip: Option<Peripherals<'static>>,
    bs: bool
}

static mut GS: GlobalState =
    GlobalState{disp: None,
                i2c: None,
                i2c_inited: false,
                buff: [0; 6],
                time: Clock{sec: 0, min: 0, hr: 0, reset: 0},
                perip: None,
                bs: false};

fn get_gs() -> &'static mut GlobalState {
    unsafe {&mut GS}
}

fn digits2bcds(digs: &[u8]) -> u32 {
    let mut res: u32 = 0;
    for d in digs.iter().rev() {
        res = (res << 4) | (*d as u32);
    }
    res
}

fn display() {
    let gs = get_gs();
    gs.disp.as_ref().unwrap().output_bits(digits2bcds(&gs.buff[..]));
}

fn digits_countup() {
    let gs = get_gs();
    let mut digits = gs.buff;
    gs.disp.as_ref().unwrap().output_bits(digits2bcds(&digits[..]));
    let mut i = 0;
    let mut carry = 1;
    while carry > 0 && i < digits.len() {
        digits[i] += carry;
        carry = if digits[i] > 9 {digits[i] = 0; 1} else {0};
        i += 1;
    }
}

fn render_clock() {
    let gs = get_gs();
    let mut digits = gs.buff;
    let time = &gs.time;
    if gs.bs {
        digits[1] = time.sec / 10; digits[0] = time.sec - digits[1] * 10;
        digits[3] = time.min / 10; digits[2] = time.min - digits[3] * 10;
        digits[5] = time.hr / 10; digits[4] = time.hr - digits[5] * 10;
    } else {
        for i in &mut digits {
            *i = 0xf;
        }