Merge pull request #2422 from embassy-rs/cleanup-docs

Cleanup docs and example

3 files changed, 54 insertions, 15 deletions

diff --git a/examples/rp/.cargo/config.toml b/examples/rp/.cargo/config.toml
index 3d7d61740..04490c789 100644
--- a/examples/rp/.cargo/config.toml
+++ b/examples/rp/.cargo/config.toml
@@ -1,5 +1,5 @@
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
-runner = "probe-rs run --chip RP2040"
+runner = "probe-rs run --chip RP2040 --probe 1209:4853:0e0039001450563641333620"
 
 [build]
 target = "thumbv6m-none-eabi"        # Cortex-M0 and Cortex-M0+
diff --git a/examples/rp/src/bin/blinky_two_channels.rs b/examples/rp/src/bin/blinky_two_channels.rs
new file mode 100644
index 000000000..b2eec2a21
--- /dev/null
+++ b/examples/rp/src/bin/blinky_two_channels.rs
@@ -0,0 +1,50 @@
+#![no_std]
+#![no_main]
+/// This example demonstrates how to access a given pin from more than one embassy task
+/// The on-board LED is toggled by two tasks with slightly different periods, leading to the
+/// apparent duty cycle of the LED increasing, then decreasing, linearly. The phenomenon is similar
+/// to interference and the 'beats' you can hear if you play two frequencies close to one another
+/// [Link explaining it](https://www.physicsclassroom.com/class/sound/Lesson-3/Interference-and-Beats)
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_rp::gpio;
+use embassy_sync::blocking_mutex::raw::ThreadModeRawMutex;
+use embassy_sync::channel::{Channel, Sender};
+use embassy_time::{Duration, Ticker};
+use gpio::{AnyPin, Level, Output};
+use {defmt_rtt as _, panic_probe as _};
+
+enum LedState {
+    Toggle,
+}
+static CHANNEL: Channel<ThreadModeRawMutex, LedState, 64> = Channel::new();
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_rp::init(Default::default());
+    let mut led = Output::new(AnyPin::from(p.PIN_25), Level::High);
+
+    let dt = 100 * 1_000_000;
+    let k = 1.003;
+
+    unwrap!(spawner.spawn(toggle_led(CHANNEL.sender(), Duration::from_nanos(dt))));
+    unwrap!(spawner.spawn(toggle_led(
+        CHANNEL.sender(),
+        Duration::from_nanos((dt as f64 * k) as u64)
+    )));
+
+    loop {
+        match CHANNEL.receive().await {
+            LedState::Toggle => led.toggle(),
+        }
+    }
+}
+
+#[embassy_executor::task(pool_size = 2)]
+async fn toggle_led(control: Sender<'static, ThreadModeRawMutex, LedState, 64>, delay: Duration) {
+    let mut ticker = Ticker::every(delay);
+    loop {
+        control.send(LedState::Toggle).await;
+        ticker.next().await;
+    }
+}
diff --git a/examples/rp/src/bin/blinky_two_tasks.rs b/examples/rp/src/bin/blinky_two_tasks.rs
index 7e0b531e1..a03f3a592 100644
--- a/examples/rp/src/bin/blinky_two_tasks.rs
+++ b/examples/rp/src/bin/blinky_two_tasks.rs
@@ -30,13 +30,11 @@ async fn main(spawner: Spawner) {
     let dt = 100 * 1_000_000;
     let k = 1.003;
 
-    unwrap!(spawner.spawn(toggle(&LED, Duration::from_nanos(dt))));
-    unwrap!(spawner.spawn(toggle_slightly_slower(
-        &LED,
-        Duration::from_nanos((dt as f64 * k) as u64)
-    )));
+    unwrap!(spawner.spawn(toggle_led(&LED, Duration::from_nanos(dt))));
+    unwrap!(spawner.spawn(toggle_led(&LED, Duration::from_nanos((dt as f64 * k) as u64))));
 }
 
+#[embassy_executor::task(pool_size = 2)]
 async fn toggle_led(led: &'static LedType, delay: Duration) {
     let mut ticker = Ticker::every(delay);
     loop {
@@ -49,12 +47,3 @@ async fn toggle_led(led: &'static LedType, delay: Duration) {
         ticker.next().await;
     }
 }
-#[embassy_executor::task]
-async fn toggle(led: &'static LedType, delay: Duration) {
-    toggle_led(led, delay).await
-}
-
-#[embassy_executor::task]
-async fn toggle_slightly_slower(led: &'static LedType, delay: Duration) {
-    toggle_led(led, delay).await
-}