Merge pull request #14 from timokroeger/uarte-power-optimization

UARTE power optimization and improvements

embassy-nrf/src/util/mod.rs

@@ -1,2 +1,12 @@
 pub mod peripheral;
 pub mod ring_buffer;
+
+/// Low power blocking wait loop using WFE/SEV.
+pub fn low_power_wait_until(mut condition: impl FnMut() -> bool) {
+    while !condition() {
+        // WFE might "eat" an event that would have otherwise woken the executor.
+        cortex_m::asm::wfe();
+    }
+    // Retrigger an event to be transparent to the executor.
+    cortex_m::asm::sev();
+}