From 2498fbdf52e1477ffbfcd8fafba1b04edaf8bc8c Mon Sep 17 00:00:00 2001 From: Vasil Nikolov Date: Tue, 9 Jan 2024 00:26:48 +0200 Subject: add example of pin sharing between tasks --- examples/rp/src/bin/blinky_two_tasks.rs | 61 +++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 examples/rp/src/bin/blinky_two_tasks.rs (limited to 'examples') diff --git a/examples/rp/src/bin/blinky_two_tasks.rs b/examples/rp/src/bin/blinky_two_tasks.rs new file mode 100644 index 000000000..d6c23b546 --- /dev/null +++ b/examples/rp/src/bin/blinky_two_tasks.rs @@ -0,0 +1,61 @@ +#![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, PeripheralRef}; +use embassy_sync::blocking_mutex::raw::ThreadModeRawMutex; +use embassy_sync::mutex::Mutex; +use embassy_time::Duration; +use embassy_time::{Ticker, Timer}; +use gpio::{AnyPin, Level, Output}; +use {defmt_rtt as _, panic_probe as _}; + +type LedType = Mutex>>>; +static LED: LedType = Mutex::new(None); + +#[embassy_executor::main] +async fn main(spawner: Spawner) { + let p = embassy_rp::init(Default::default()); + // set the content of the global LED reference to the real LED pin + let led = Output::new(AnyPin::from(p.PIN_25), Level::High); + // inner scope is so that once the mutex is written to, the MutexGuard is dropped, thus the + // Mutex is released + { + *(LED.lock().await) = Some(PeripheralRef::new(led)); + } + 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) + ))); +} + +async fn toggle_led(led: &'static LedType, delay: Duration) { + let mut ticker = Ticker::every(delay); + loop { + { + let mut led_unlocked = led.lock().await; + if let Some(pin_ref) = led_unlocked.as_mut() { + pin_ref.toggle(); + } + } + 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 +} -- cgit From ebf46d37aa7b8fd103c6d6008879f89f01cde70a Mon Sep 17 00:00:00 2001 From: Vasil Nikolov Date: Tue, 9 Jan 2024 00:35:11 +0200 Subject: remove unused import --- examples/rp/src/bin/blinky_two_tasks.rs | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'examples') diff --git a/examples/rp/src/bin/blinky_two_tasks.rs b/examples/rp/src/bin/blinky_two_tasks.rs index d6c23b546..6b4d35165 100644 --- a/examples/rp/src/bin/blinky_two_tasks.rs +++ b/examples/rp/src/bin/blinky_two_tasks.rs @@ -10,8 +10,7 @@ use embassy_executor::Spawner; use embassy_rp::{gpio, PeripheralRef}; use embassy_sync::blocking_mutex::raw::ThreadModeRawMutex; use embassy_sync::mutex::Mutex; -use embassy_time::Duration; -use embassy_time::{Ticker, Timer}; +use embassy_time::{Duration, Ticker}; use gpio::{AnyPin, Level, Output}; use {defmt_rtt as _, panic_probe as _}; -- cgit From 4843c060d0fcad11eb639558ccbf18d6362e94c1 Mon Sep 17 00:00:00 2001 From: Vasil Nikolov Date: Wed, 10 Jan 2024 00:47:45 +0200 Subject: no need for a PeripheralRef --- examples/rp/src/bin/blinky_two_tasks.rs | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'examples') diff --git a/examples/rp/src/bin/blinky_two_tasks.rs b/examples/rp/src/bin/blinky_two_tasks.rs index 6b4d35165..7e0b531e1 100644 --- a/examples/rp/src/bin/blinky_two_tasks.rs +++ b/examples/rp/src/bin/blinky_two_tasks.rs @@ -7,14 +7,14 @@ /// [Link explaining it](https://www.physicsclassroom.com/class/sound/Lesson-3/Interference-and-Beats) use defmt::*; use embassy_executor::Spawner; -use embassy_rp::{gpio, PeripheralRef}; +use embassy_rp::gpio; use embassy_sync::blocking_mutex::raw::ThreadModeRawMutex; use embassy_sync::mutex::Mutex; use embassy_time::{Duration, Ticker}; use gpio::{AnyPin, Level, Output}; use {defmt_rtt as _, panic_probe as _}; -type LedType = Mutex>>>; +type LedType = Mutex>>; static LED: LedType = Mutex::new(None); #[embassy_executor::main] @@ -25,7 +25,7 @@ async fn main(spawner: Spawner) { // inner scope is so that once the mutex is written to, the MutexGuard is dropped, thus the // Mutex is released { - *(LED.lock().await) = Some(PeripheralRef::new(led)); + *(LED.lock().await) = Some(led); } let dt = 100 * 1_000_000; let k = 1.003; -- cgit