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-rw-r--r--book/en/src/by-example/tips_monotonic_impl.md58
1 files changed, 11 insertions, 47 deletions
diff --git a/book/en/src/by-example/tips_monotonic_impl.md b/book/en/src/by-example/tips_monotonic_impl.md
index 608281a5..fdecfc2b 100644
--- a/book/en/src/by-example/tips_monotonic_impl.md
+++ b/book/en/src/by-example/tips_monotonic_impl.md
@@ -11,55 +11,19 @@ RTIC 0.6 we have moved to assume the user has a time library, e.g. [`fugit`] or
as the basis for all time-based operations when implementing `Monotonic`. This is why in RTIC 0.6
it is almost trivial to implement the `Monotonic` trait and use any timer in a system for scheduling.
-The trait documents the requirements for each method, however a small PoC implementation is provided
-below.
+The trait documents the requirements for each method, however below you can find a list of
+implementations in the wild that can be used as inspiration:
+
+- [`STM32F411 timers`], implemented for the 32-bit timers
+- [`Systick based`], runs at a fixed rate - some overhead but simple
+- [`DWT and Systick based`], a more efficient `Systick` based implementation, but requires `DWT`
+
+If you know of more implementations feel free to add them to this list.
[`rtic_monotonic::Monotonic`]: https://docs.rs/rtic-monotonic/
[`fugit`]: https://docs.rs/fugit/
[`embedded_time`]: https://docs.rs/embedded_time/
+[`STM32F411 timers`]: https://github.com/kalkyl/f411-rtic/blob/main/src/bin/mono.rs
+[`Systick based`]: https://github.com/rtic-rs/systick-monotonic
+[`DWT and Systick based`]: https://github.com/rtic-rs/dwt-systick-monotonic
-```rust
-pub use fugit::{self, ExtU32};
-use rtic_monotonic::Monotonic;
-
-/// Example wrapper struct for a timer
-pub struct Timer<const TIMER_HZ: u32> {
- tim: TIM2,
-}
-
-impl<const TIMER_HZ: u32> Monotonic for Timer<TIMER_HZ> {
- type Instant = fugit::TimerInstantU32<TIMER_HZ>;
- type Duration = fugit::TimerDurationU32<TIMER_HZ>;
-
- fn now(&mut self) -> Self::Instant {
- // Read the timer count
- Self::Instant::from_ticks(Self::count())
- }
-
- fn zero() -> Self::Instant {
- // This is used while the app is in `#[init]`, if the system cannot
- // support time in `#[init]` this can also be a `panic!(..)`
- Self::Instant::from_ticks(0)
- }
-
- unsafe fn reset(&mut self) {
- // Reset timer counter
- self.tim.cnt.write(|_, w| w.bits(0));
-
- // Since reset is only called once, we use it to enable
- // the interrupt generation bit.
- self.tim.dier.modify(|_, w| w.cc1ie().set_bit());
- }
-
- fn set_compare(&mut self, instant: Instant<Self>) {
- // Use Compare channel 1 for Monotonic
- self.tim
- .ccr1
- .write(|w| w.ccr().bits(instant.ticks()));
- }
-
- fn clear_compare_flag(&mut self) {
- self.tim.sr.modify(|_, w| w.cc1if().clear_bit());
- }
-}
-```