forked from M-Labs/thermostat
49 lines
1.1 KiB
Rust
49 lines
1.1 KiB
Rust
use core::cell::RefCell;
|
|
use core::ops::Deref;
|
|
use cortex_m::interrupt::Mutex;
|
|
use cortex_m_rt::exception;
|
|
use stm32f4xx_hal::{
|
|
rcc::Clocks,
|
|
time::U32Ext,
|
|
timer::{Timer, Event as TimerEvent},
|
|
stm32::SYST,
|
|
};
|
|
|
|
/// Rate in Hz
|
|
const TIMER_RATE: u32 = 500;
|
|
/// Interval duration in milliseconds
|
|
const TIMER_DELTA: u32 = 1000 / TIMER_RATE;
|
|
/// Elapsed time in milliseconds
|
|
static TIMER_MS: Mutex<RefCell<u32>> = Mutex::new(RefCell::new(0));
|
|
|
|
/// Setup SysTick exception
|
|
pub fn setup(syst: SYST, clocks: Clocks) {
|
|
let mut timer = Timer::syst(syst, TIMER_RATE.hz(), clocks);
|
|
timer.listen(TimerEvent::TimeOut);
|
|
}
|
|
|
|
/// SysTick exception (Timer)
|
|
#[exception]
|
|
fn SysTick() {
|
|
cortex_m::interrupt::free(|cs| {
|
|
*TIMER_MS.borrow(cs)
|
|
.borrow_mut() += TIMER_DELTA;
|
|
});
|
|
}
|
|
|
|
/// Obtain current time in milliseconds
|
|
pub fn now() -> u32 {
|
|
cortex_m::interrupt::free(|cs| {
|
|
*TIMER_MS.borrow(cs)
|
|
.borrow()
|
|
.deref()
|
|
})
|
|
}
|
|
|
|
/// block for at least `amount` milliseconds
|
|
pub fn sleep(amount: u32) {
|
|
use crate::timer::now;
|
|
let start = now();
|
|
while now() - start <= amount {}
|
|
}
|