Add timeout_at convenience function and example.

1 files changed, 80 insertions, 0 deletions

diff --git a/examples/rp/src/bin/debounce.rs b/examples/rp/src/bin/debounce.rs
new file mode 100644
index 000000000..bf1579091
--- /dev/null
+++ b/examples/rp/src/bin/debounce.rs
@@ -0,0 +1,80 @@
+//! This example shows the ease of debouncing a button with async rust.
+//! Hook up a button or switch between pin 9 and ground.
+
+#![no_std]
+#![no_main]
+
+use defmt::info;
+use embassy_executor::Spawner;
+use embassy_rp::gpio::{Input, Level, Pull};
+use embassy_time::{timeout_at, Duration, Instant, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+pub struct Debouncer<'a> {
+    input: Input<'a>,
+    debounce: Duration,
+}
+
+impl<'a> Debouncer<'a> {
+    pub fn new(input: Input<'a>, debounce: Duration) -> Self {
+        Self { input, debounce }
+    }
+
+    pub async fn debounce(&mut self) -> Level {
+        loop {
+            let l1 = self.input.get_level();
+
+            self.input.wait_for_any_edge().await;
+
+            Timer::after(self.debounce).await;
+
+            let l2 = self.input.get_level();
+            if l1 != l2 {
+                break l2;
+            }
+        }
+    }
+}
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_rp::init(Default::default());
+    let mut btn = Debouncer::new(Input::new(p.PIN_9, Pull::Up), Duration::from_millis(20));
+
+    info!("Debounce Demo");
+
+    loop {
+        // button pressed
+        btn.debounce().await;
+        let start = Instant::now();
+        info!("Button Press");
+
+        match timeout_at(start + Duration::from_secs(1), btn.debounce()).await {
+            // Button Released < 1s
+            Ok(_) => {
+                info!("Button pressed for: {}ms", start.elapsed().as_millis());
+                continue;
+            }
+            // button held for > 1s
+            Err(_) => {
+                info!("Button Held");
+            }
+        }
+
+        match timeout_at(start + Duration::from_secs(5), btn.debounce()).await {
+            // Button released <5s
+            Ok(_) => {
+                info!("Button pressed for: {}ms", start.elapsed().as_millis());
+                continue;
+            }
+            // button held for > >5s
+            Err(_) => {
+                info!("Button Long Held");
+            }
+        }
+
+        // wait for button release before handling another press
+        btn.debounce().await;
+        info!("Button pressed for: {}ms", start.elapsed().as_millis());
+    }
+}