Fix nrf monotonics (#852)

* Fix nrf::timer

* Bootstrap nrf52840-blinky example

* More work on nrf blinky example

* Fix README

* Add asserts for correct timer functionality

* Add correctness check to other monotonics as well

* Update Changelog

* Fix potential timing issues

* Fix race condition in nrf::rtc

* Add changelog

* Add rtc blinky example

* Change rtc example to RC lf clock source

* Add changelog to rtic-time

* Add changelog

* Attempt to fix CI

* Update teensy4-blinky Cargo.lock

1 files changed, 4 insertions, 2 deletions

diff --git a/rtic-monotonics/src/stm32.rs b/rtic-monotonics/src/stm32.rs
index c86005ef..601196a3 100644
--- a/rtic-monotonics/src/stm32.rs
+++ b/rtic-monotonics/src/stm32.rs
@@ -272,12 +272,14 @@ macro_rules! make_timer {
                 // Full period
                 if $timer.sr().read().uif() {
                     $timer.sr().modify(|r| r.set_uif(false));
-                    $overflow.fetch_add(1, Ordering::Relaxed);
+                    let prev = $overflow.fetch_add(1, Ordering::Relaxed);
+                    assert!(prev % 2 == 1, "Monotonic must have missed an interrupt!");
                 }
                 // Half period
                 if $timer.sr().read().ccif(2) {
                     $timer.sr().modify(|r| r.set_ccif(2, false));
-                    $overflow.fetch_add(1, Ordering::Relaxed);
+                    let prev = $overflow.fetch_add(1, Ordering::Relaxed);
+                    assert!(prev % 2 == 0, "Monotonic must have missed an interrupt!");
                 }
             }
         }