embedded_hal/
delay.rs

1//! Delays.
2
3/// Nanoseconds per microsecond
4const NANOS_PER_MICRO: u32 = 1_000;
5/// Nanoseconds per millisecond
6const NANOS_PER_MILLI: u32 = 1_000_000;
7
8/// Delay with up to nanosecond precision.
9pub trait DelayNs {
10    /// Pauses execution for at minimum `ns` nanoseconds. Pause can be longer
11    /// if the implementation requires it due to precision/timing issues.
12    fn delay_ns(&mut self, ns: u32);
13
14    /// Pauses execution for at minimum `us` microseconds. Pause can be longer
15    /// if the implementation requires it due to precision/timing issues.
16    fn delay_us(&mut self, mut us: u32) {
17        const MAX_MICROS: u32 = u32::MAX / NANOS_PER_MICRO;
18
19        // Avoid potential overflow if micro -> nano conversion is too large
20        while us > MAX_MICROS {
21            us -= MAX_MICROS;
22            self.delay_ns(MAX_MICROS * NANOS_PER_MICRO);
23        }
24
25        self.delay_ns(us * NANOS_PER_MICRO);
26    }
27
28    /// Pauses execution for at minimum `ms` milliseconds. Pause can be longer
29    /// if the implementation requires it due to precision/timing issues.
30    #[inline]
31    fn delay_ms(&mut self, mut ms: u32) {
32        const MAX_MILLIS: u32 = u32::MAX / NANOS_PER_MILLI;
33
34        // Avoid potential overflow if milli -> nano conversion is too large
35        while ms > MAX_MILLIS {
36            ms -= MAX_MILLIS;
37            self.delay_ns(MAX_MILLIS * NANOS_PER_MILLI);
38        }
39
40        self.delay_ns(ms * NANOS_PER_MILLI);
41    }
42}
43
44impl<T> DelayNs for &mut T
45where
46    T: DelayNs + ?Sized,
47{
48    #[inline]
49    fn delay_ns(&mut self, ns: u32) {
50        T::delay_ns(self, ns);
51    }
52
53    #[inline]
54    fn delay_us(&mut self, us: u32) {
55        T::delay_us(self, us);
56    }
57
58    #[inline]
59    fn delay_ms(&mut self, ms: u32) {
60        T::delay_ms(self, ms);
61    }
62}
embedded_hal/delay.rs

embedded_hal/
delay.rs
