Trait embedded_hal::timer::CountDown
source · pub trait CountDown {
type Time;
// Required methods
fn start<T>(&mut self, count: T)
where T: Into<Self::Time>;
fn wait(&mut self) -> Result<(), Void>;
}
Expand description
A count down timer
Contract
self.start(count); block!(self.wait());
MUST block for AT LEAST the time specified bycount
.
Note that the implementer doesn’t necessarily have to be a downcounting timer; it could also be an upcounting timer as long as the above contract is upheld.
Examples
You can use this timer to create delays
extern crate embedded_hal as hal;
#[macro_use(block)]
extern crate nb;
use hal::prelude::*;
fn main() {
let mut led: Led = {
// ..
};
let mut timer: Timer6 = {
// ..
};
Led.on();
timer.start(1.s());
block!(timer.wait()); // blocks for 1 second
Led.off();
}
Required Associated Types§
Required Methods§
sourcefn wait(&mut self) -> Result<(), Void>
fn wait(&mut self) -> Result<(), Void>
Non-blockingly “waits” until the count down finishes
Contract
- If
Self: Periodic
, the timer will start a new count down right after the last one finishes. - Otherwise the behavior of calling
wait
after the last call returnedOk
is UNSPECIFIED. Implementers are suggested to panic on this scenario to signal a programmer error.