Merge #854

854: Implement IWDG timeout calculation r=Dirbaio a=chemicstry

Allow specifying `IndependentWatchdog` timeout as `Duration` instead of prescaler value.

Since IWDG is clocked from LSI, which differs between families, I standardized HSI/LSI definitions in RCC and used that.

Co-authored-by: chemicstry <[email protected]>

1 files changed, 46 insertions, 0 deletions

diff --git a/examples/stm32f4/src/bin/wdt.rs b/examples/stm32f4/src/bin/wdt.rs
new file mode 100644
index 000000000..bfc487c31
--- /dev/null
+++ b/examples/stm32f4/src/bin/wdt.rs
@@ -0,0 +1,46 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_stm32::gpio::{Level, Output, Speed};
+use embassy_stm32::wdg::IndependentWatchdog;
+use embassy_stm32::Peripherals;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let mut led = Output::new(p.PB7, Level::High, Speed::Low);
+
+    let mut wdt = IndependentWatchdog::new(p.IWDG, 1_000_000);
+    unsafe {
+        wdt.unleash();
+    }
+
+    let mut i = 0;
+
+    loop {
+        info!("high");
+        led.set_high();
+        Timer::after(Duration::from_millis(300)).await;
+
+        info!("low");
+        led.set_low();
+        Timer::after(Duration::from_millis(300)).await;
+
+        // Pet watchdog for 5 iterations and then stop.
+        // MCU should restart in 1 second after the last pet.
+        if i < 5 {
+            info!("Petting watchdog");
+            unsafe {
+                wdt.pet();
+            }
+        }
+
+        i += 1;
+    }
+}