Move examples to a subdirectory

47 files changed, 2491 insertions, 0 deletions

diff --git a/examples/nrf/.cargo/config.toml b/examples/nrf/.cargo/config.toml
new file mode 100644
index 000000000..58ac3debd
--- /dev/null
+++ b/examples/nrf/.cargo/config.toml
@@ -0,0 +1,21 @@
+[unstable]
+build-std = ["core"]
+
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+# replace nRF82840_xxAA with your chip as listed in `probe-run --list-chips`
+runner = "probe-run --chip nRF52840_xxAA"
+
+rustflags = [
+  # LLD (shipped with the Rust toolchain) is used as the default linker
+  "-C", "link-arg=--nmagic",
+  "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=-Tdefmt.x",
+
+  # Code-size optimizations.
+  "-Z", "trap-unreachable=no",
+  "-C", "inline-threshold=5",
+  "-C", "no-vectorize-loops",
+]
+
+[build]
+target = "thumbv7em-none-eabi"
diff --git a/examples/nrf/Cargo.toml b/examples/nrf/Cargo.toml
new file mode 100644
index 000000000..fa1dab360
--- /dev/null
+++ b/examples/nrf/Cargo.toml
@@ -0,0 +1,31 @@
+[package]
+authors = ["Dario Nieuwenhuis <[email protected]>"]
+edition = "2018"
+name = "embassy-nrf-examples"
+version = "0.1.0"
+
+[features]
+default = [
+    "defmt-default",
+]
+defmt-default = []
+defmt-trace = []
+defmt-debug = []
+defmt-info = []
+defmt-warn = []
+defmt-error = []
+
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-trace"] }
+embassy-traits = { version = "0.1.0", path = "../../embassy-traits", features = ["defmt"] }
+embassy-nrf = { version = "0.1.0", path = "../../embassy-nrf", features = ["defmt", "defmt-trace", "nrf52840"] }
+
+defmt = "0.2.0"
+defmt-rtt = "0.2.0"
+
+cortex-m = { version = "0.7.1", features = ["inline-asm"] }
+cortex-m-rt = "0.6.13"
+embedded-hal    = { version = "0.2.4" }
+panic-probe = { version = "0.2.0", features = ["print-defmt"] }
+futures = { version = "0.3.8", default-features = false, features = ["async-await"] }
diff --git a/examples/nrf/build.rs b/examples/nrf/build.rs
new file mode 100644
index 000000000..d534cc3df
--- /dev/null
+++ b/examples/nrf/build.rs
@@ -0,0 +1,31 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+}
diff --git a/examples/nrf/memory.x b/examples/nrf/memory.x
new file mode 100644
index 000000000..9b04edec0
--- /dev/null
+++ b/examples/nrf/memory.x
@@ -0,0 +1,7 @@
+MEMORY
+{
+  /* NOTE 1 K = 1 KiBi = 1024 bytes */
+  /* These values correspond to the NRF52840 with Softdevices S140 7.0.1 */
+  FLASH : ORIGIN = 0x00000000, LENGTH = 1024K
+  RAM : ORIGIN = 0x20000000, LENGTH = 256K
+}
diff --git a/examples/nrf/src/bin/blinky.rs b/examples/nrf/src/bin/blinky.rs
new file mode 100644
index 000000000..8f12cfda9
--- /dev/null
+++ b/examples/nrf/src/bin/blinky.rs
@@ -0,0 +1,28 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_nrf::gpio::{Level, Output, OutputDrive};
+use embassy_nrf::Peripherals;
+use embedded_hal::digital::v2::OutputPin;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let mut led = Output::new(p.P0_13, Level::Low, OutputDrive::Standard);
+
+    loop {
+        led.set_high().unwrap();
+        Timer::after(Duration::from_millis(300)).await;
+        led.set_low().unwrap();
+        Timer::after(Duration::from_millis(300)).await;
+    }
+}
diff --git a/examples/nrf/src/bin/buffered_uart.rs b/examples/nrf/src/bin/buffered_uart.rs
new file mode 100644
index 000000000..c800e64fc
--- /dev/null
+++ b/examples/nrf/src/bin/buffered_uart.rs
@@ -0,0 +1,68 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::io::{AsyncBufReadExt, AsyncWriteExt};
+use embassy_nrf::gpio::NoPin;
+use embassy_nrf::{buffered_uarte::BufferedUarte, interrupt, uarte, Peripherals};
+use example_common::*;
+use futures::pin_mut;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let mut config = uarte::Config::default();
+    config.parity = uarte::Parity::EXCLUDED;
+    config.baudrate = uarte::Baudrate::BAUD115200;
+
+    let mut tx_buffer = [0u8; 4096];
+    let mut rx_buffer = [0u8; 4096];
+
+    let irq = interrupt::take!(UARTE0_UART0);
+    let u = unsafe {
+        BufferedUarte::new(
+            p.UARTE0,
+            p.TIMER0,
+            p.PPI_CH0,
+            p.PPI_CH1,
+            irq,
+            p.P0_08,
+            p.P0_06,
+            NoPin,
+            NoPin,
+            config,
+            &mut rx_buffer,
+            &mut tx_buffer,
+        )
+    };
+    pin_mut!(u);
+
+    info!("uarte initialized!");
+
+    unwrap!(u.write_all(b"Hello!\r\n").await);
+    info!("wrote hello in uart!");
+
+    // Simple demo, reading 8-char chunks and echoing them back reversed.
+    loop {
+        info!("reading...");
+        let mut buf = [0u8; 8];
+        unwrap!(u.read_exact(&mut buf).await);
+        info!("read done, got {}", buf);
+
+        // Reverse buf
+        for i in 0..4 {
+            buf.swap(i, 7 - i);
+        }
+
+        info!("writing...");
+        unwrap!(u.write_all(&buf).await);
+        info!("write done");
+    }
+}
diff --git a/examples/nrf/src/bin/executor_fairness_test.rs b/examples/nrf/src/bin/executor_fairness_test.rs
new file mode 100644
index 000000000..797be4335
--- /dev/null
+++ b/examples/nrf/src/bin/executor_fairness_test.rs
@@ -0,0 +1,47 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use core::task::Poll;
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Instant, Timer};
+use embassy_nrf::{interrupt, Peripherals};
+
+#[embassy::task]
+async fn run1() {
+    loop {
+        info!("DING DONG");
+        Timer::after(Duration::from_ticks(16000)).await;
+    }
+}
+
+#[embassy::task]
+async fn run2() {
+    loop {
+        Timer::at(Instant::from_ticks(0)).await;
+    }
+}
+
+#[embassy::task]
+async fn run3() {
+    futures::future::poll_fn(|cx| {
+        cx.waker().wake_by_ref();
+        Poll::<()>::Pending
+    })
+    .await;
+}
+
+#[embassy::main]
+async fn main(spawner: Spawner, _p: Peripherals) {
+    unwrap!(spawner.spawn(run1()));
+    unwrap!(spawner.spawn(run2()));
+    unwrap!(spawner.spawn(run3()));
+}
diff --git a/examples/nrf/src/bin/gpiote_channel.rs b/examples/nrf/src/bin/gpiote_channel.rs
new file mode 100644
index 000000000..9800aed98
--- /dev/null
+++ b/examples/nrf/src/bin/gpiote_channel.rs
@@ -0,0 +1,72 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy_nrf::gpio::{Input, Pull};
+use embassy_nrf::gpiote::{InputChannel, InputChannelPolarity};
+use embassy_nrf::{interrupt, Peripherals};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Starting!");
+
+    let ch1 = InputChannel::new(
+        p.GPIOTE_CH0,
+        Input::new(p.P0_11, Pull::Up),
+        InputChannelPolarity::HiToLo,
+    );
+    let ch2 = InputChannel::new(
+        p.GPIOTE_CH1,
+        Input::new(p.P0_12, Pull::Up),
+        InputChannelPolarity::LoToHi,
+    );
+    let ch3 = InputChannel::new(
+        p.GPIOTE_CH2,
+        Input::new(p.P0_24, Pull::Up),
+        InputChannelPolarity::Toggle,
+    );
+    let ch4 = InputChannel::new(
+        p.GPIOTE_CH3,
+        Input::new(p.P0_25, Pull::Up),
+        InputChannelPolarity::Toggle,
+    );
+
+    let button1 = async {
+        loop {
+            ch1.wait().await;
+            info!("Button 1 pressed")
+        }
+    };
+
+    let button2 = async {
+        loop {
+            ch2.wait().await;
+            info!("Button 2 released")
+        }
+    };
+
+    let button3 = async {
+        loop {
+            ch3.wait().await;
+            info!("Button 3 toggled")
+        }
+    };
+
+    let button4 = async {
+        loop {
+            ch4.wait().await;
+            info!("Button 4 toggled")
+        }
+    };
+
+    futures::join!(button1, button2, button3, button4);
+}
diff --git a/examples/nrf/src/bin/gpiote_port.rs b/examples/nrf/src/bin/gpiote_port.rs
new file mode 100644
index 000000000..4a7951cd3
--- /dev/null
+++ b/examples/nrf/src/bin/gpiote_port.rs
@@ -0,0 +1,43 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::traits::gpio::{WaitForHigh, WaitForLow};
+use embassy_nrf::gpio::{AnyPin, Input, Pin as _, Pull};
+use embassy_nrf::gpiote::PortInput;
+use embassy_nrf::interrupt;
+use embassy_nrf::Peripherals;
+use example_common::*;
+
+#[embassy::task(pool_size = 4)]
+async fn button_task(n: usize, mut pin: PortInput<'static, AnyPin>) {
+    loop {
+        pin.wait_for_low().await;
+        info!("Button {:?} pressed!", n);
+        pin.wait_for_high().await;
+        info!("Button {:?} released!", n);
+    }
+}
+
+#[embassy::main]
+async fn main(spawner: Spawner, p: Peripherals) {
+    info!("Starting!");
+
+    let btn1 = PortInput::new(Input::new(p.P0_11.degrade(), Pull::Up));
+    let btn2 = PortInput::new(Input::new(p.P0_12.degrade(), Pull::Up));
+    let btn3 = PortInput::new(Input::new(p.P0_24.degrade(), Pull::Up));
+    let btn4 = PortInput::new(Input::new(p.P0_25.degrade(), Pull::Up));
+
+    spawner.spawn(button_task(1, btn1)).unwrap();
+    spawner.spawn(button_task(2, btn2)).unwrap();
+    spawner.spawn(button_task(3, btn3)).unwrap();
+    spawner.spawn(button_task(4, btn4)).unwrap();
+}
diff --git a/examples/nrf/src/bin/multiprio.rs b/examples/nrf/src/bin/multiprio.rs
new file mode 100644
index 000000000..79fa029b3
--- /dev/null
+++ b/examples/nrf/src/bin/multiprio.rs
@@ -0,0 +1,162 @@
+//! This example showcases how to create multiple Executor instances to run tasks at
+//! different priority levels.
+//!
+//! Low priority executor runs in thread mode (not interrupt), and uses `sev` for signaling
+//! there's work in the queue, and `wfe` for waiting for work.
+//!
+//! Medium and high priority executors run in two interrupts with different priorities.
+//! Signaling work is done by pending the interrupt. No "waiting" needs to be done explicitly, since
+//! when there's work the interrupt will trigger and run the executor.
+//!
+//! Sample output below. Note that high priority ticks can interrupt everything else, and
+//! medium priority computations can interrupt low priority computations, making them to appear
+//! to take significantly longer time.
+//!
+//! ```not_rust
+//!     [med] Starting long computation
+//!     [med] done in 992 ms
+//!         [high] tick!
+//! [low] Starting long computation
+//!     [med] Starting long computation
+//!         [high] tick!
+//!         [high] tick!
+//!     [med] done in 993 ms
+//!     [med] Starting long computation
+//!         [high] tick!
+//!         [high] tick!
+//!     [med] done in 993 ms
+//! [low] done in 3972 ms
+//!     [med] Starting long computation
+//!         [high] tick!
+//!         [high] tick!
+//!     [med] done in 993 ms
+//! ```
+//!
+//! For comparison, try changing the code so all 3 tasks get spawned on the low priority executor.
+//! You will get an output like the following. Note that no computation is ever interrupted.
+//!
+//! ```not_rust
+//!         [high] tick!
+//!     [med] Starting long computation
+//!     [med] done in 496 ms
+//! [low] Starting long computation
+//! [low] done in 992 ms
+//!     [med] Starting long computation
+//!     [med] done in 496 ms
+//!         [high] tick!
+//! [low] Starting long computation
+//! [low] done in 992 ms
+//!         [high] tick!
+//!     [med] Starting long computation
+//!     [med] done in 496 ms
+//!         [high] tick!
+//! ```
+//!
+
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use cortex_m_rt::entry;
+use defmt::panic;
+use embassy::executor::{Executor, InterruptExecutor};
+use embassy::interrupt::InterruptExt;
+use embassy::time::{Duration, Instant, Timer};
+use embassy::util::Forever;
+use embassy_nrf::{interrupt, peripherals, rtc};
+
+#[embassy::task]
+async fn run_high() {
+    loop {
+        info!("        [high] tick!");
+        Timer::after(Duration::from_ticks(27374)).await;
+    }
+}
+
+#[embassy::task]
+async fn run_med() {
+    loop {
+        let start = Instant::now();
+        info!("    [med] Starting long computation");
+
+        // Spin-wait to simulate a long CPU computation
+        cortex_m::asm::delay(32_000_000); // ~1 second
+
+        let end = Instant::now();
+        let ms = end.duration_since(start).as_ticks() / 33;
+        info!("    [med] done in {} ms", ms);
+
+        Timer::after(Duration::from_ticks(23421)).await;
+    }
+}
+
+#[embassy::task]
+async fn run_low() {
+    loop {
+        let start = Instant::now();
+        info!("[low] Starting long computation");
+
+        // Spin-wait to simulate a long CPU computation
+        cortex_m::asm::delay(64_000_000); // ~2 seconds
+
+        let end = Instant::now();
+        let ms = end.duration_since(start).as_ticks() / 33;
+        info!("[low] done in {} ms", ms);
+
+        Timer::after(Duration::from_ticks(32983)).await;
+    }
+}
+
+static RTC: Forever<rtc::RTC<peripherals::RTC1>> = Forever::new();
+static ALARM_HIGH: Forever<rtc::Alarm<peripherals::RTC1>> = Forever::new();
+static EXECUTOR_HIGH: Forever<InterruptExecutor<interrupt::SWI1_EGU1>> = Forever::new();
+static ALARM_MED: Forever<rtc::Alarm<peripherals::RTC1>> = Forever::new();
+static EXECUTOR_MED: Forever<InterruptExecutor<interrupt::SWI0_EGU0>> = Forever::new();
+static ALARM_LOW: Forever<rtc::Alarm<peripherals::RTC1>> = Forever::new();
+static EXECUTOR_LOW: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let p = embassy_nrf::init(Default::default());
+
+    let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
+    rtc.start();
+    unsafe { embassy::time::set_clock(rtc) };
+
+    // High-priority executor: SWI1_EGU1, priority level 6
+    let irq = interrupt::take!(SWI1_EGU1);
+    irq.set_priority(interrupt::Priority::P6);
+    let alarm = ALARM_HIGH.put(rtc.alarm2());
+    let executor = EXECUTOR_HIGH.put(InterruptExecutor::new(irq));
+    executor.set_alarm(alarm);
+    executor.start(|spawner| {
+        unwrap!(spawner.spawn(run_high()));
+    });
+
+    // Medium-priority executor: SWI0_EGU0, priority level 7
+    let irq = interrupt::take!(SWI0_EGU0);
+    irq.set_priority(interrupt::Priority::P7);
+    let alarm = ALARM_MED.put(rtc.alarm1());
+    let executor = EXECUTOR_MED.put(InterruptExecutor::new(irq));
+    executor.set_alarm(alarm);
+    executor.start(|spawner| {
+        unwrap!(spawner.spawn(run_med()));
+    });
+
+    // Low priority executor: runs in thread mode, using WFE/SEV
+    let alarm = ALARM_LOW.put(rtc.alarm0());
+    let executor = EXECUTOR_LOW.put(Executor::new());
+    executor.set_alarm(alarm);
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(run_low()));
+    });
+}
diff --git a/examples/nrf/src/bin/ppi.rs b/examples/nrf/src/bin/ppi.rs
new file mode 100644
index 000000000..717604b9e
--- /dev/null
+++ b/examples/nrf/src/bin/ppi.rs
@@ -0,0 +1,87 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use core::future::pending;
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy_nrf::gpio::{Input, Level, Output, OutputDrive, Pull};
+use embassy_nrf::gpiote::{self, InputChannel, InputChannelPolarity};
+use embassy_nrf::ppi::Ppi;
+use embassy_nrf::{interrupt, Peripherals};
+use gpiote::{OutputChannel, OutputChannelPolarity};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Starting!");
+
+    let button1 = InputChannel::new(
+        p.GPIOTE_CH0,
+        Input::new(p.P0_11, Pull::Up),
+        InputChannelPolarity::HiToLo,
+    );
+    let button2 = InputChannel::new(
+        p.GPIOTE_CH1,
+        Input::new(p.P0_12, Pull::Up),
+        InputChannelPolarity::HiToLo,
+    );
+    let button3 = InputChannel::new(
+        p.GPIOTE_CH2,
+        Input::new(p.P0_24, Pull::Up),
+        InputChannelPolarity::HiToLo,
+    );
+    let button4 = InputChannel::new(
+        p.GPIOTE_CH3,
+        Input::new(p.P0_25, Pull::Up),
+        InputChannelPolarity::HiToLo,
+    );
+
+    let led1 = OutputChannel::new(
+        p.GPIOTE_CH4,
+        Output::new(p.P0_13, Level::Low, OutputDrive::Standard),
+        OutputChannelPolarity::Toggle,
+    );
+
+    let led2 = OutputChannel::new(
+        p.GPIOTE_CH5,
+        Output::new(p.P0_14, Level::Low, OutputDrive::Standard),
+        OutputChannelPolarity::Toggle,
+    );
+
+    let mut ppi = Ppi::new(p.PPI_CH0);
+    ppi.set_event(button1.event_in());
+    ppi.set_task(led1.task_out());
+    ppi.enable();
+
+    let mut ppi = Ppi::new(p.PPI_CH1);
+    ppi.set_event(button2.event_in());
+    ppi.set_task(led1.task_clr());
+    ppi.enable();
+
+    let mut ppi = Ppi::new(p.PPI_CH2);
+    ppi.set_event(button3.event_in());
+    ppi.set_task(led1.task_set());
+    ppi.enable();
+
+    let mut ppi = Ppi::new(p.PPI_CH3);
+    ppi.set_event(button4.event_in());
+    ppi.set_task(led1.task_out());
+    ppi.set_fork_task(led2.task_out());
+    ppi.enable();
+
+    info!("PPI setup!");
+    info!("Press button 1 to toggle LED 1");
+    info!("Press button 2 to turn on LED 1");
+    info!("Press button 3 to turn off LED 1");
+    info!("Press button 4 to toggle LEDs 1 and 2");
+
+    // Block forever so the above drivers don't get dropped
+    pending::<()>().await;
+}
diff --git a/examples/nrf/src/bin/pwm.rs b/examples/nrf/src/bin/pwm.rs
new file mode 100644
index 000000000..d2874a29b
--- /dev/null
+++ b/examples/nrf/src/bin/pwm.rs
@@ -0,0 +1,104 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use defmt::{panic, *};
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_nrf::pwm::{Prescaler, Pwm};
+use embassy_nrf::{interrupt, Peripherals};
+
+// for i in range(1024): print(int((math.sin(i/512*math.pi)*0.4+0.5)**2*32767), ', ', end='')
+static DUTY: [u16; 1024] = [
+    8191, 8272, 8353, 8434, 8516, 8598, 8681, 8764, 8847, 8931, 9015, 9099, 9184, 9269, 9354, 9440,
+    9526, 9613, 9700, 9787, 9874, 9962, 10050, 10139, 10227, 10316, 10406, 10495, 10585, 10675,
+    10766, 10857, 10948, 11039, 11131, 11223, 11315, 11407, 11500, 11592, 11685, 11779, 11872,
+    11966, 12060, 12154, 12248, 12343, 12438, 12533, 12628, 12723, 12818, 12914, 13010, 13106,
+    13202, 13298, 13394, 13491, 13587, 13684, 13781, 13878, 13975, 14072, 14169, 14266, 14364,
+    14461, 14558, 14656, 14754, 14851, 14949, 15046, 15144, 15242, 15339, 15437, 15535, 15632,
+    15730, 15828, 15925, 16023, 16120, 16218, 16315, 16412, 16510, 16607, 16704, 16801, 16898,
+    16995, 17091, 17188, 17284, 17380, 17477, 17572, 17668, 17764, 17859, 17955, 18050, 18145,
+    18239, 18334, 18428, 18522, 18616, 18710, 18803, 18896, 18989, 19082, 19174, 19266, 19358,
+    19449, 19540, 19631, 19722, 19812, 19902, 19991, 20081, 20169, 20258, 20346, 20434, 20521,
+    20608, 20695, 20781, 20867, 20952, 21037, 21122, 21206, 21290, 21373, 21456, 21538, 21620,
+    21701, 21782, 21863, 21943, 22022, 22101, 22179, 22257, 22335, 22412, 22488, 22564, 22639,
+    22714, 22788, 22861, 22934, 23007, 23079, 23150, 23220, 23290, 23360, 23429, 23497, 23564,
+    23631, 23698, 23763, 23828, 23892, 23956, 24019, 24081, 24143, 24204, 24264, 24324, 24383,
+    24441, 24499, 24555, 24611, 24667, 24721, 24775, 24828, 24881, 24933, 24983, 25034, 25083,
+    25132, 25180, 25227, 25273, 25319, 25363, 25407, 25451, 25493, 25535, 25575, 25615, 25655,
+    25693, 25731, 25767, 25803, 25838, 25873, 25906, 25939, 25971, 26002, 26032, 26061, 26089,
+    26117, 26144, 26170, 26195, 26219, 26242, 26264, 26286, 26307, 26327, 26346, 26364, 26381,
+    26397, 26413, 26427, 26441, 26454, 26466, 26477, 26487, 26496, 26505, 26512, 26519, 26525,
+    26530, 26534, 26537, 26539, 26540, 26541, 26540, 26539, 26537, 26534, 26530, 26525, 26519,
+    26512, 26505, 26496, 26487, 26477, 26466, 26454, 26441, 26427, 26413, 26397, 26381, 26364,
+    26346, 26327, 26307, 26286, 26264, 26242, 26219, 26195, 26170, 26144, 26117, 26089, 26061,
+    26032, 26002, 25971, 25939, 25906, 25873, 25838, 25803, 25767, 25731, 25693, 25655, 25615,
+    25575, 25535, 25493, 25451, 25407, 25363, 25319, 25273, 25227, 25180, 25132, 25083, 25034,
+    24983, 24933, 24881, 24828, 24775, 24721, 24667, 24611, 24555, 24499, 24441, 24383, 24324,
+    24264, 24204, 24143, 24081, 24019, 23956, 23892, 23828, 23763, 23698, 23631, 23564, 23497,
+    23429, 23360, 23290, 23220, 23150, 23079, 23007, 22934, 22861, 22788, 22714, 22639, 22564,
+    22488, 22412, 22335, 22257, 22179, 22101, 22022, 21943, 21863, 21782, 21701, 21620, 21538,
+    21456, 21373, 21290, 21206, 21122, 21037, 20952, 20867, 20781, 20695, 20608, 20521, 20434,
+    20346, 20258, 20169, 20081, 19991, 19902, 19812, 19722, 19631, 19540, 19449, 19358, 19266,
+    19174, 19082, 18989, 18896, 18803, 18710, 18616, 18522, 18428, 18334, 18239, 18145, 18050,
+    17955, 17859, 17764, 17668, 17572, 17477, 17380, 17284, 17188, 17091, 16995, 16898, 16801,
+    16704, 16607, 16510, 16412, 16315, 16218, 16120, 16023, 15925, 15828, 15730, 15632, 15535,
+    15437, 15339, 15242, 15144, 15046, 14949, 14851, 14754, 14656, 14558, 14461, 14364, 14266,
+    14169, 14072, 13975, 13878, 13781, 13684, 13587, 13491, 13394, 13298, 13202, 13106, 13010,
+    12914, 12818, 12723, 12628, 12533, 12438, 12343, 12248, 12154, 12060, 11966, 11872, 11779,
+    11685, 11592, 11500, 11407, 11315, 11223, 11131, 11039, 10948, 10857, 10766, 10675, 10585,
+    10495, 10406, 10316, 10227, 10139, 10050, 9962, 9874, 9787, 9700, 9613, 9526, 9440, 9354, 9269,
+    9184, 9099, 9015, 8931, 8847, 8764, 8681, 8598, 8516, 8434, 8353, 8272, 8191, 8111, 8031, 7952,
+    7873, 7794, 7716, 7638, 7561, 7484, 7407, 7331, 7255, 7180, 7105, 7031, 6957, 6883, 6810, 6738,
+    6665, 6594, 6522, 6451, 6381, 6311, 6241, 6172, 6104, 6036, 5968, 5901, 5834, 5767, 5702, 5636,
+    5571, 5507, 5443, 5379, 5316, 5253, 5191, 5130, 5068, 5008, 4947, 4888, 4828, 4769, 4711, 4653,
+    4596, 4539, 4482, 4426, 4371, 4316, 4261, 4207, 4153, 4100, 4047, 3995, 3943, 3892, 3841, 3791,
+    3741, 3691, 3642, 3594, 3546, 3498, 3451, 3404, 3358, 3312, 3267, 3222, 3178, 3134, 3090, 3047,
+    3005, 2962, 2921, 2879, 2839, 2798, 2758, 2719, 2680, 2641, 2603, 2565, 2528, 2491, 2454, 2418,
+    2382, 2347, 2312, 2278, 2244, 2210, 2177, 2144, 2112, 2080, 2048, 2017, 1986, 1956, 1926, 1896,
+    1867, 1838, 1810, 1781, 1754, 1726, 1699, 1673, 1646, 1620, 1595, 1570, 1545, 1520, 1496, 1472,
+    1449, 1426, 1403, 1380, 1358, 1336, 1315, 1294, 1273, 1252, 1232, 1212, 1192, 1173, 1154, 1135,
+    1117, 1099, 1081, 1063, 1046, 1029, 1012, 996, 980, 964, 948, 933, 918, 903, 888, 874, 860,
+    846, 833, 819, 806, 793, 781, 768, 756, 744, 733, 721, 710, 699, 688, 677, 667, 657, 647, 637,
+    627, 618, 609, 599, 591, 582, 574, 565, 557, 549, 541, 534, 526, 519, 512, 505, 498, 492, 485,
+    479, 473, 467, 461, 455, 450, 444, 439, 434, 429, 424, 419, 415, 410, 406, 402, 398, 394, 390,
+    386, 383, 379, 376, 373, 370, 367, 364, 361, 359, 356, 354, 351, 349, 347, 345, 343, 342, 340,
+    338, 337, 336, 334, 333, 332, 331, 330, 330, 329, 328, 328, 328, 327, 327, 327, 327, 327, 328,
+    328, 328, 329, 330, 330, 331, 332, 333, 334, 336, 337, 338, 340, 342, 343, 345, 347, 349, 351,
+    354, 356, 359, 361, 364, 367, 370, 373, 376, 379, 383, 386, 390, 394, 398, 402, 406, 410, 415,
+    419, 424, 429, 434, 439, 444, 450, 455, 461, 467, 473, 479, 485, 492, 498, 505, 512, 519, 526,
+    534, 541, 549, 557, 565, 574, 582, 591, 599, 609, 618, 627, 637, 647, 657, 667, 677, 688, 699,
+    710, 721, 733, 744, 756, 768, 781, 793, 806, 819, 833, 846, 860, 874, 888, 903, 918, 933, 948,
+    964, 980, 996, 1012, 1029, 1046, 1063, 1081, 1099, 1117, 1135, 1154, 1173, 1192, 1212, 1232,
+    1252, 1273, 1294, 1315, 1336, 1358, 1380, 1403, 1426, 1449, 1472, 1496, 1520, 1545, 1570, 1595,
+    1620, 1646, 1673, 1699, 1726, 1754, 1781, 1810, 1838, 1867, 1896, 1926, 1956, 1986, 2017, 2048,
+    2080, 2112, 2144, 2177, 2210, 2244, 2278, 2312, 2347, 2382, 2418, 2454, 2491, 2528, 2565, 2603,
+    2641, 2680, 2719, 2758, 2798, 2839, 2879, 2921, 2962, 3005, 3047, 3090, 3134, 3178, 3222, 3267,
+    3312, 3358, 3404, 3451, 3498, 3546, 3594, 3642, 3691, 3741, 3791, 3841, 3892, 3943, 3995, 4047,
+    4100, 4153, 4207, 4261, 4316, 4371, 4426, 4482, 4539, 4596, 4653, 4711, 4769, 4828, 4888, 4947,
+    5008, 5068, 5130, 5191, 5253, 5316, 5379, 5443, 5507, 5571, 5636, 5702, 5767, 5834, 5901, 5968,
+    6036, 6104, 6172, 6241, 6311, 6381, 6451, 6522, 6594, 6665, 6738, 6810, 6883, 6957, 7031, 7105,
+    7180, 7255, 7331, 7407, 7484, 7561, 7638, 7716, 7794, 7873, 7952, 8031, 8111,
+];
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let pwm = Pwm::new(p.PWM0, p.P0_13, p.P0_14, p.P0_16, p.P0_15);
+    pwm.set_prescaler(Prescaler::Div1);
+    info!("pwm initialized!");
+
+    let mut i = 0;
+    loop {
+        i += 1;
+        pwm.set_duty(0, DUTY[i % 1024]);
+        pwm.set_duty(1, DUTY[(i + 256) % 1024]);
+        pwm.set_duty(2, DUTY[(i + 512) % 1024]);
+        pwm.set_duty(3, DUTY[(i + 768) % 1024]);
+        Timer::after(Duration::from_millis(3)).await;
+    }
+}
diff --git a/examples/nrf/src/bin/qspi.rs b/examples/nrf/src/bin/qspi.rs
new file mode 100644
index 000000000..6e49887a4
--- /dev/null
+++ b/examples/nrf/src/bin/qspi.rs
@@ -0,0 +1,84 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::{assert_eq, panic};
+use embassy::executor::Spawner;
+use embassy::traits::flash::Flash;
+use embassy_nrf::Peripherals;
+use embassy_nrf::{interrupt, qspi};
+use example_common::*;
+
+const PAGE_SIZE: usize = 4096;
+
+// Workaround for alignment requirements.
+// Nicer API will probably come in the future.
+#[repr(C, align(4))]
+struct AlignedBuf([u8; 4096]);
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    // Config for the MX25R64 present in the nRF52840 DK
+    let mut config = qspi::Config::default();
+    config.read_opcode = qspi::ReadOpcode::READ4IO;
+    config.write_opcode = qspi::WriteOpcode::PP4IO;
+    config.write_page_size = qspi::WritePageSize::_256BYTES;
+
+    let irq = interrupt::take!(QSPI);
+    let mut q = qspi::Qspi::new(
+        p.QSPI, irq, p.P0_19, p.P0_17, p.P0_20, p.P0_21, p.P0_22, p.P0_23, config,
+    )
+    .await;
+
+    let mut id = [1; 3];
+    q.custom_instruction(0x9F, &[], &mut id).await.unwrap();
+    info!("id: {}", id);
+
+    // Read status register
+    let mut status = [4; 1];
+    q.custom_instruction(0x05, &[], &mut status).await.unwrap();
+
+    info!("status: {:?}", status[0]);
+
+    if status[0] & 0x40 == 0 {
+        status[0] |= 0x40;
+
+        q.custom_instruction(0x01, &status, &mut []).await.unwrap();
+
+        info!("enabled quad in status");
+    }
+
+    let mut buf = AlignedBuf([0u8; PAGE_SIZE]);
+
+    let pattern = |a: u32| (a ^ (a >> 8) ^ (a >> 16) ^ (a >> 24)) as u8;
+
+    for i in 0..8 {
+        info!("page {:?}: erasing... ", i);
+        q.erase(i * PAGE_SIZE).await.unwrap();
+
+        for j in 0..PAGE_SIZE {
+            buf.0[j] = pattern((j + i * PAGE_SIZE) as u32);
+        }
+
+        info!("programming...");
+        q.write(i * PAGE_SIZE, &buf.0).await.unwrap();
+    }
+
+    for i in 0..8 {
+        info!("page {:?}: reading... ", i);
+        q.read(i * PAGE_SIZE, &mut buf.0).await.unwrap();
+
+        info!("verifying...");
+        for j in 0..PAGE_SIZE {
+            assert_eq!(buf.0[j], pattern((j + i * PAGE_SIZE) as u32));
+        }
+    }
+
+    info!("done!")
+}
diff --git a/examples/nrf/src/bin/qspi_lowpower.rs b/examples/nrf/src/bin/qspi_lowpower.rs
new file mode 100644
index 000000000..ece3243b6
--- /dev/null
+++ b/examples/nrf/src/bin/qspi_lowpower.rs
@@ -0,0 +1,85 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use core::mem;
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy::traits::flash::Flash;
+use embassy_nrf::Peripherals;
+use embassy_nrf::{interrupt, qspi};
+use example_common::*;
+
+// Workaround for alignment requirements.
+// Nicer API will probably come in the future.
+#[repr(C, align(4))]
+struct AlignedBuf([u8; 64]);
+
+#[embassy::main]
+async fn main(_spawner: Spawner, mut p: Peripherals) {
+    let mut irq = interrupt::take!(QSPI);
+
+    loop {
+        // Config for the MX25R64 present in the nRF52840 DK
+        let mut config = qspi::Config::default();
+        config.read_opcode = qspi::ReadOpcode::READ4IO;
+        config.write_opcode = qspi::WriteOpcode::PP4IO;
+        config.write_page_size = qspi::WritePageSize::_256BYTES;
+        config.deep_power_down = Some(qspi::DeepPowerDownConfig {
+            enter_time: 3, // tDP = 30uS
+            exit_time: 3,  // tRDP = 35uS
+        });
+
+        let mut q = qspi::Qspi::new(
+            &mut p.QSPI,
+            &mut irq,
+            &mut p.P0_19,
+            &mut p.P0_17,
+            &mut p.P0_20,
+            &mut p.P0_21,
+            &mut p.P0_22,
+            &mut p.P0_23,
+            config,
+        )
+        .await;
+
+        let mut id = [1; 3];
+        q.custom_instruction(0x9F, &[], &mut id).await.unwrap();
+        info!("id: {}", id);
+
+        // Read status register
+        let mut status = [4; 1];
+        q.custom_instruction(0x05, &[], &mut status).await.unwrap();
+
+        info!("status: {:?}", status[0]);
+
+        if status[0] & 0x40 == 0 {
+            status[0] |= 0x40;
+
+            q.custom_instruction(0x01, &status, &mut []).await.unwrap();
+
+            info!("enabled quad in status");
+        }
+
+        let mut buf = AlignedBuf([0u8; 64]);
+
+        info!("reading...");
+        q.read(0, &mut buf.0).await.unwrap();
+        info!("read: {=[u8]:x}", buf.0);
+
+        // Drop the QSPI instance. This disables the peripehral and deconfigures the pins.
+        // This clears the borrow on the singletons, so they can now be used again.
+        mem::drop(q);
+
+        // Sleep for 1 second. The executor ensures the core sleeps with a WFE when it has nothing to do.
+        // During this sleep, the nRF chip should only use ~3uA
+        Timer::after(Duration::from_secs(1)).await;
+    }
+}
diff --git a/examples/nrf/src/bin/raw_spawn.rs b/examples/nrf/src/bin/raw_spawn.rs
new file mode 100644
index 000000000..78de7b100
--- /dev/null
+++ b/examples/nrf/src/bin/raw_spawn.rs
@@ -0,0 +1,65 @@
+#![no_std]
+#![no_main]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use core::mem;
+use cortex_m_rt::entry;
+use defmt::panic;
+use embassy::executor::raw::Task;
+use embassy::executor::Executor;
+use embassy::time::{Duration, Timer};
+use embassy::util::Forever;
+use embassy_nrf::peripherals;
+use embassy_nrf::{interrupt, rtc};
+
+async fn run1() {
+    loop {
+        info!("BIG INFREQUENT TICK");
+        Timer::after(Duration::from_ticks(64000)).await;
+    }
+}
+
+async fn run2() {
+    loop {
+        info!("tick");
+        Timer::after(Duration::from_ticks(13000)).await;
+    }
+}
+
+static RTC: Forever<rtc::RTC<peripherals::RTC1>> = Forever::new();
+static ALARM: Forever<rtc::Alarm<peripherals::RTC1>> = Forever::new();
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let p = embassy_nrf::init(Default::default());
+
+    let rtc = RTC.put(rtc::RTC::new(p.RTC1, interrupt::take!(RTC1)));
+    rtc.start();
+    unsafe { embassy::time::set_clock(rtc) };
+
+    let alarm = ALARM.put(rtc.alarm0());
+    let executor = EXECUTOR.put(Executor::new());
+    executor.set_alarm(alarm);
+
+    let run1_task = Task::new();
+    let run2_task = Task::new();
+
+    // Safety: these variables do live forever if main never returns.
+    let run1_task = unsafe { make_static(&run1_task) };
+    let run2_task = unsafe { make_static(&run2_task) };
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(run1_task.spawn(|| run1())));
+        unwrap!(spawner.spawn(run2_task.spawn(|| run2())));
+    });
+}
+
+unsafe fn make_static<T>(t: &T) -> &'static T {
+    mem::transmute(t)
+}
diff --git a/examples/nrf/src/bin/spim.rs b/examples/nrf/src/bin/spim.rs
new file mode 100644
index 000000000..c42cc6015
--- /dev/null
+++ b/examples/nrf/src/bin/spim.rs
@@ -0,0 +1,76 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy_nrf::gpio::{Level, Output, OutputDrive};
+use embassy_nrf::Peripherals;
+use embassy_nrf::{interrupt, spim};
+use embassy_traits::spi::FullDuplex;
+use embedded_hal::digital::v2::*;
+use example_common::*;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("running!");
+
+    let mut config = spim::Config::default();
+    config.frequency = spim::Frequency::M16;
+
+    let irq = interrupt::take!(SPIM3);
+    let mut spim = spim::Spim::new(p.SPI3, irq, p.P0_29, p.P0_28, p.P0_30, config);
+
+    let mut ncs = Output::new(p.P0_31, Level::High, OutputDrive::Standard);
+
+    // Example on how to talk to an ENC28J60 chip
+
+    // softreset
+    cortex_m::asm::delay(10);
+    ncs.set_low().unwrap();
+    cortex_m::asm::delay(5);
+    let tx = [0xFF];
+    unwrap!(spim.read_write(&mut [], &tx).await);
+    cortex_m::asm::delay(10);
+    ncs.set_high().unwrap();
+
+    cortex_m::asm::delay(100000);
+
+    let mut rx = [0; 2];
+
+    // read ESTAT
+    cortex_m::asm::delay(5000);
+    ncs.set_low().unwrap();
+    cortex_m::asm::delay(5000);
+    let tx = [0b000_11101, 0];
+    unwrap!(spim.read_write(&mut rx, &tx).await);
+    cortex_m::asm::delay(5000);
+    ncs.set_high().unwrap();
+    info!("estat: {=[?]}", rx);
+
+    // Switch to bank 3
+    cortex_m::asm::delay(10);
+    ncs.set_low().unwrap();
+    cortex_m::asm::delay(5);
+    let tx = [0b100_11111, 0b11];
+    unwrap!(spim.read_write(&mut rx, &tx).await);
+    cortex_m::asm::delay(10);
+    ncs.set_high().unwrap();
+
+    // read EREVID
+    cortex_m::asm::delay(10);
+    ncs.set_low().unwrap();
+    cortex_m::asm::delay(5);
+    let tx = [0b000_10010, 0];
+    unwrap!(spim.read_write(&mut rx, &tx).await);
+    cortex_m::asm::delay(10);
+    ncs.set_high().unwrap();
+
+    info!("erevid: {=[?]}", rx);
+}
diff --git a/examples/nrf/src/bin/timer.rs b/examples/nrf/src/bin/timer.rs
new file mode 100644
index 000000000..43f6d76ce
--- /dev/null
+++ b/examples/nrf/src/bin/timer.rs
@@ -0,0 +1,37 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_nrf::Peripherals;
+use example_common::*;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+
+#[embassy::task]
+async fn run1() {
+    loop {
+        info!("BIG INFREQUENT TICK");
+        Timer::after(Duration::from_ticks(64000)).await;
+    }
+}
+
+#[embassy::task]
+async fn run2() {
+    loop {
+        info!("tick");
+        Timer::after(Duration::from_ticks(13000)).await;
+    }
+}
+
+#[embassy::main]
+async fn main(spawner: Spawner, _p: Peripherals) {
+    unwrap!(spawner.spawn(run1()));
+    unwrap!(spawner.spawn(run2()));
+}
diff --git a/examples/nrf/src/bin/twim.rs b/examples/nrf/src/bin/twim.rs
new file mode 100644
index 000000000..537cea160
--- /dev/null
+++ b/examples/nrf/src/bin/twim.rs
@@ -0,0 +1,35 @@
+//! Example on how to read a 24C/24LC i2c eeprom.
+//!
+//! Connect SDA to P0.03, SCL to P0.04
+
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::{panic, *};
+use embassy::executor::Spawner;
+use embassy_nrf::twim::{self, Twim};
+use embassy_nrf::{interrupt, Peripherals};
+
+const ADDRESS: u8 = 0x50;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Initializing TWI...");
+    let config = twim::Config::default();
+    let irq = interrupt::take!(SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0);
+    let mut twi = Twim::new(p.TWISPI0, irq, p.P0_03, p.P0_04, config);
+
+    info!("Reading...");
+
+    let mut buf = [0u8; 16];
+    twi.write_then_read(ADDRESS, &mut [0x00], &mut buf).unwrap();
+
+    info!("Read: {=[u8]:x}", buf);
+}
diff --git a/examples/nrf/src/bin/twim_lowpower.rs b/examples/nrf/src/bin/twim_lowpower.rs
new file mode 100644
index 000000000..1cd66a18e
--- /dev/null
+++ b/examples/nrf/src/bin/twim_lowpower.rs
@@ -0,0 +1,54 @@
+//! Example on how to read a 24C/24LC i2c eeprom with low power consumption.
+//! The eeprom is read every 1 second, while ensuring lowest possible power while
+//! sleeping between reads.
+//!
+//! Connect SDA to P0.03, SCL to P0.04
+
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use core::mem;
+
+use defmt::{panic, *};
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_nrf::twim::{self, Twim};
+use embassy_nrf::{interrupt, Peripherals};
+
+const ADDRESS: u8 = 0x50;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, mut p: Peripherals) {
+    info!("Started!");
+    let mut irq = interrupt::take!(SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0);
+
+    loop {
+        info!("Initializing TWI...");
+        let config = twim::Config::default();
+
+        // Create the TWIM instance with borrowed singletons, so they're not consumed.
+        let mut twi = Twim::new(&mut p.TWISPI0, &mut irq, &mut p.P0_03, &mut p.P0_04, config);
+
+        info!("Reading...");
+
+        let mut buf = [0u8; 16];
+        twi.write_then_read(ADDRESS, &mut [0x00], &mut buf).unwrap();
+
+        info!("Read: {=[u8]:x}", buf);
+
+        // Drop the TWIM instance. This disables the peripehral and deconfigures the pins.
+        // This clears the borrow on the singletons, so they can now be used again.
+        mem::drop(twi);
+
+        // Sleep for 1 second. The executor ensures the core sleeps with a WFE when it has nothing to do.
+        // During this sleep, the nRF chip should only use ~3uA
+        Timer::after(Duration::from_secs(1)).await;
+    }
+}
diff --git a/examples/nrf/src/bin/uart.rs b/examples/nrf/src/bin/uart.rs
new file mode 100644
index 000000000..e65e2fe51
--- /dev/null
+++ b/examples/nrf/src/bin/uart.rs
@@ -0,0 +1,43 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use example_common::*;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::traits::uart::{Read, Write};
+use embassy_nrf::gpio::NoPin;
+use embassy_nrf::{interrupt, uarte, Peripherals};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let mut config = uarte::Config::default();
+    config.parity = uarte::Parity::EXCLUDED;
+    config.baudrate = uarte::Baudrate::BAUD115200;
+
+    let irq = interrupt::take!(UARTE0_UART0);
+    let mut uart =
+        unsafe { uarte::Uarte::new(p.UARTE0, irq, p.P0_08, p.P0_06, NoPin, NoPin, config) };
+
+    info!("uarte initialized!");
+
+    // Message must be in SRAM
+    let mut buf = [0; 8];
+    buf.copy_from_slice(b"Hello!\r\n");
+
+    unwrap!(uart.write(&buf).await);
+    info!("wrote hello in uart!");
+
+    loop {
+        info!("reading...");
+        unwrap!(uart.read(&mut buf).await);
+        info!("writing...");
+        unwrap!(uart.write(&buf).await);
+    }
+}
diff --git a/examples/nrf/src/bin/uart_idle.rs b/examples/nrf/src/bin/uart_idle.rs
new file mode 100644
index 000000000..dc2c73433
--- /dev/null
+++ b/examples/nrf/src/bin/uart_idle.rs
@@ -0,0 +1,46 @@
+#![no_std]
+#![no_main]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_traits::uart::ReadUntilIdle;
+use example_common::*;
+
+use defmt::panic;
+use embassy::executor::Spawner;
+use embassy::traits::uart::Write;
+use embassy_nrf::gpio::NoPin;
+use embassy_nrf::{interrupt, uarte, Peripherals};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let mut config = uarte::Config::default();
+    config.parity = uarte::Parity::EXCLUDED;
+    config.baudrate = uarte::Baudrate::BAUD115200;
+
+    let irq = interrupt::take!(UARTE0_UART0);
+    let mut uart = unsafe {
+        uarte::UarteWithIdle::new(
+            p.UARTE0, p.TIMER0, p.PPI_CH0, p.PPI_CH1, irq, p.P0_08, p.P0_06, NoPin, NoPin, config,
+        )
+    };
+
+    info!("uarte initialized!");
+
+    // Message must be in SRAM
+    let mut buf = [0; 8];
+    buf.copy_from_slice(b"Hello!\r\n");
+
+    unwrap!(uart.write(&buf).await);
+    info!("wrote hello in uart!");
+
+    loop {
+        info!("reading...");
+        let n = unwrap!(uart.read_until_idle(&mut buf).await);
+        info!("got {} bytes", n);
+    }
+}
diff --git a/examples/nrf/src/example_common.rs b/examples/nrf/src/example_common.rs
new file mode 100644
index 000000000..54d633837
--- /dev/null
+++ b/examples/nrf/src/example_common.rs
@@ -0,0 +1,17 @@
+#![macro_use]
+
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+pub use defmt::*;
+
+use core::sync::atomic::{AtomicUsize, Ordering};
+
+defmt::timestamp! {"{=u64}", {
+        static COUNT: AtomicUsize = AtomicUsize::new(0);
+        // NOTE(no-CAS) `timestamps` runs with interrupts disabled
+        let n = COUNT.load(Ordering::Relaxed);
+        COUNT.store(n + 1, Ordering::Relaxed);
+        n as u64
+    }
+}
diff --git a/examples/rp/.cargo/config.toml b/examples/rp/.cargo/config.toml
new file mode 100644
index 000000000..1bbbe97da
--- /dev/null
+++ b/examples/rp/.cargo/config.toml
@@ -0,0 +1,19 @@
+[unstable]
+build-std = ["core"]
+
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+runner = "probe-run-rp --chip RP2040"
+
+rustflags = [
+  # LLD (shipped with the Rust toolchain) is used as the default linker
+  "-C", "link-arg=--nmagic",
+  "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=-Tlink-rp.x",
+  "-C", "link-arg=-Tdefmt.x",
+
+  # Code-size optimizations.
+  "-Z", "trap-unreachable=no",
+]
+
+[build]
+target = "thumbv6m-none-eabi"        # Cortex-M0 and Cortex-M0+
diff --git a/examples/rp/Cargo.toml b/examples/rp/Cargo.toml
new file mode 100644
index 000000000..71b48129f
--- /dev/null
+++ b/examples/rp/Cargo.toml
@@ -0,0 +1,32 @@
+[package]
+authors = ["Dario Nieuwenhuis <[email protected]>"]
+edition = "2018"
+name = "embassy-rp-examples"
+version = "0.1.0"
+
+[features]
+default = [
+    "defmt-default",
+]
+defmt-default = []
+defmt-trace = []
+defmt-debug = []
+defmt-info = []
+defmt-warn = []
+defmt-error = []
+
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-trace"] }
+embassy-rp = { version = "0.1.0", path = "../../embassy-rp", features = ["defmt", "defmt-trace"] }
+rp2040-pac2 = { git = "https://github.com/Dirbaio/rp2040-pac", rev="254f4677937801155ca3cb17c7bb9d38eb62683e" }
+atomic-polyfill = { version = "0.1.1" }
+
+defmt = "0.2.0"
+defmt-rtt = "0.2.0"
+
+cortex-m = { version = "0.7.1", features = ["inline-asm"] }
+cortex-m-rt = "0.6.13"
+embedded-hal    = { version = "0.2.4" }
+panic-probe = { version = "0.2.0", features = ["print-defmt"] }
+futures = { version = "0.3.8", default-features = false, features = ["async-await", "cfg-target-has-atomic", "unstable"] }
diff --git a/examples/rp/build.rs b/examples/rp/build.rs
new file mode 100644
index 000000000..d534cc3df
--- /dev/null
+++ b/examples/rp/build.rs
@@ -0,0 +1,31 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+}
diff --git a/examples/rp/memory.x b/examples/rp/memory.x
new file mode 100644
index 000000000..aba861aae
--- /dev/null
+++ b/examples/rp/memory.x
@@ -0,0 +1,5 @@
+MEMORY {
+    BOOT2 : ORIGIN = 0x10000000, LENGTH = 0x100
+    FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
+    RAM   : ORIGIN = 0x20000000, LENGTH = 256K
+}
\ No newline at end of file
diff --git a/examples/rp/src/bin/blinky.rs b/examples/rp/src/bin/blinky.rs
new file mode 100644
index 000000000..e42999912
--- /dev/null
+++ b/examples/rp/src/bin/blinky.rs
@@ -0,0 +1,31 @@
+#![no_std]
+#![no_main]
+#![feature(asm)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use defmt::*;
+use embassy::executor::Spawner;
+use embassy_rp::{gpio, Peripherals};
+use embedded_hal::digital::v2::OutputPin;
+use gpio::{Level, Output};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let mut led = Output::new(p.PIN_25, Level::Low);
+
+    loop {
+        info!("led on!");
+        led.set_high().unwrap();
+        cortex_m::asm::delay(1_000_000);
+
+        info!("led off!");
+        led.set_low().unwrap();
+        cortex_m::asm::delay(1_000_000);
+    }
+}
diff --git a/examples/rp/src/bin/button.rs b/examples/rp/src/bin/button.rs
new file mode 100644
index 000000000..c4d942ff5
--- /dev/null
+++ b/examples/rp/src/bin/button.rs
@@ -0,0 +1,29 @@
+#![no_std]
+#![no_main]
+#![feature(asm)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use embassy::executor::Spawner;
+use embassy_rp::gpio::{Input, Level, Output, Pull};
+use embassy_rp::Peripherals;
+use embedded_hal::digital::v2::{InputPin, OutputPin};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let button = Input::new(p.PIN_28, Pull::Up);
+    let mut led = Output::new(p.PIN_25, Level::Low);
+
+    loop {
+        if button.is_high().unwrap() {
+            led.set_high().unwrap();
+        } else {
+            led.set_low().unwrap();
+        }
+    }
+}
diff --git a/examples/rp/src/bin/uart.rs b/examples/rp/src/bin/uart.rs
new file mode 100644
index 000000000..8b5f2a53b
--- /dev/null
+++ b/examples/rp/src/bin/uart.rs
@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+#![feature(asm)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use embassy::executor::Spawner;
+use embassy_rp::{uart, Peripherals};
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    let config = uart::Config::default();
+    let mut uart = uart::Uart::new(p.UART0, p.PIN_0, p.PIN_1, p.PIN_2, p.PIN_3, config);
+    uart.send("Hello World!\r\n".as_bytes());
+
+    loop {
+        uart.send("hello there!\r\n".as_bytes());
+        cortex_m::asm::delay(1_000_000);
+    }
+}
diff --git a/examples/rp/src/example_common.rs b/examples/rp/src/example_common.rs
new file mode 100644
index 000000000..f7c4ef57a
--- /dev/null
+++ b/examples/rp/src/example_common.rs
@@ -0,0 +1,12 @@
+use core::sync::atomic::{AtomicUsize, Ordering};
+use defmt_rtt as _;
+use panic_probe as _;
+
+defmt::timestamp! {"{=u64}", {
+    static COUNT: AtomicUsize = AtomicUsize::new(0);
+    // NOTE(no-CAS) `timestamps` runs with interrupts disabled
+    let n = COUNT.load(Ordering::Relaxed);
+    COUNT.store(n + 1, Ordering::Relaxed);
+    n as u64
+}
+}
diff --git a/examples/std/Cargo.toml b/examples/std/Cargo.toml
new file mode 100644
index 000000000..04e89269d
--- /dev/null
+++ b/examples/std/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+authors = ["Dario Nieuwenhuis <[email protected]>"]
+edition = "2018"
+name = "embassy-std-examples"
+version = "0.1.0"
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["log"] }
+embassy-std = { version = "0.1.0", path = "../../embassy-std" }
+embassy-net = { version = "0.1.0", path = "../../embassy-net", features=["std", "log", "medium-ethernet", "tcp", "dhcpv4"] }
+smoltcp = { git = "https://github.com/smoltcp-rs/smoltcp", rev="ec59aba5e10cf91df0c9253d9c2aca4dd143d2ff", default-features = false }
+
+async-io = "1.3.1"
+env_logger = "0.8.2"
+futures = { version = "0.3.8", default-features = false, features = ["async-await"] }
+log = "0.4.11"
+nix = "0.21.0"
+libc = "0.2.81"
+clap = { version = "3.0.0-beta.2", features = ["derive"] }
+rand_core   = { version = "0.6.0", features = ["std"] }
+heapless            = { version = "0.5.6", default-features = false } 
diff --git a/examples/std/src/bin/net.rs b/examples/std/src/bin/net.rs
new file mode 100644
index 000000000..5a726e5d2
--- /dev/null
+++ b/examples/std/src/bin/net.rs
@@ -0,0 +1,103 @@
+#![feature(type_alias_impl_trait)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![allow(incomplete_features)]
+
+use clap::{AppSettings, Clap};
+use embassy::executor::Spawner;
+use embassy::io::AsyncWriteExt;
+use embassy::util::Forever;
+use embassy_net::*;
+use embassy_std::Executor;
+use heapless::Vec;
+use log::*;
+
+#[path = "../tuntap.rs"]
+mod tuntap;
+
+use crate::tuntap::TunTapDevice;
+
+static DEVICE: Forever<TunTapDevice> = Forever::new();
+static CONFIG: Forever<DhcpConfigurator> = Forever::new();
+
+#[derive(Clap)]
+#[clap(version = "1.0")]
+#[clap(setting = AppSettings::ColoredHelp)]
+struct Opts {
+    /// TAP device name
+    #[clap(long, default_value = "tap0")]
+    tap: String,
+}
+
+#[embassy::task]
+async fn net_task() {
+    embassy_net::run().await
+}
+
+#[embassy::task]
+async fn main_task(spawner: Spawner) {
+    let opts: Opts = Opts::parse();
+
+    // Init network device
+    let device = TunTapDevice::new(&opts.tap).unwrap();
+
+    // Static IP configuration
+    let config = StaticConfigurator::new(Config {
+        address: Ipv4Cidr::new(Ipv4Address::new(192, 168, 69, 2), 24),
+        dns_servers: Vec::new(),
+        gateway: Some(Ipv4Address::new(192, 168, 69, 1)),
+    });
+
+    // DHCP configruation
+    let config = DhcpConfigurator::new();
+
+    // Init network stack
+    embassy_net::init(DEVICE.put(device), CONFIG.put(config));
+
+    // Launch network task
+    spawner.spawn(net_task()).unwrap();
+
+    // Then we can use it!
+    let mut rx_buffer = [0; 4096];
+    let mut tx_buffer = [0; 4096];
+    let mut socket = TcpSocket::new(&mut rx_buffer, &mut tx_buffer);
+
+    socket.set_timeout(Some(embassy_net::SmolDuration::from_secs(10)));
+
+    let remote_endpoint = (Ipv4Address::new(192, 168, 69, 74), 8000);
+    info!("connecting to {:?}...", remote_endpoint);
+    let r = socket.connect(remote_endpoint).await;
+    if let Err(e) = r {
+        warn!("connect error: {:?}", e);
+        return;
+    }
+    info!("connected!");
+    loop {
+        let r = socket.write_all(b"Hello!\n").await;
+        if let Err(e) = r {
+            warn!("write error: {:?}", e);
+            return;
+        }
+    }
+}
+
+#[no_mangle]
+fn _embassy_rand(buf: &mut [u8]) {
+    use rand_core::{OsRng, RngCore};
+    OsRng.fill_bytes(buf);
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+fn main() {
+    env_logger::builder()
+        .filter_level(log::LevelFilter::Debug)
+        .filter_module("async_io", log::LevelFilter::Info)
+        .format_timestamp_nanos()
+        .init();
+
+    let executor = EXECUTOR.put(Executor::new());
+    executor.run(|spawner| {
+        spawner.spawn(main_task(spawner)).unwrap();
+    });
+}
diff --git a/examples/std/src/bin/serial.rs b/examples/std/src/bin/serial.rs
new file mode 100644
index 000000000..1b22dc0de
--- /dev/null
+++ b/examples/std/src/bin/serial.rs
@@ -0,0 +1,59 @@
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../serial_port.rs"]
+mod serial_port;
+
+use async_io::Async;
+use embassy::io::AsyncBufReadExt;
+use embassy::util::Forever;
+use embassy_std::Executor;
+use log::*;
+use nix::sys::termios;
+
+use self::serial_port::SerialPort;
+
+#[embassy::task]
+async fn run() {
+    // Open the serial port.
+    let baudrate = termios::BaudRate::B115200;
+    let port = SerialPort::new("/dev/ttyACM0", baudrate).unwrap();
+    //let port = Spy::new(port);
+
+    // Use async_io's reactor for async IO.
+    // This demonstrates how embassy's executor can drive futures from another IO library.
+    // Essentially, async_io::Async converts from AsRawFd+Read+Write to futures's AsyncRead+AsyncWrite
+    let port = Async::new(port).unwrap();
+
+    // This implements futures's AsyncBufRead based on futures's AsyncRead
+    let port = futures::io::BufReader::new(port);
+
+    // We can then use FromStdIo to convert from futures's AsyncBufRead+AsyncWrite
+    // to embassy's AsyncBufRead+AsyncWrite
+    let mut port = embassy::io::FromStdIo::new(port);
+
+    info!("Serial opened!");
+
+    loop {
+        let mut buf = [0u8; 256];
+        let n = port.read(&mut buf).await.unwrap();
+        info!("read {:?}", &buf[..n]);
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+fn main() {
+    env_logger::builder()
+        .filter_level(log::LevelFilter::Debug)
+        .filter_module("async_io", log::LevelFilter::Info)
+        .format_timestamp_nanos()
+        .init();
+
+    let executor = EXECUTOR.put(Executor::new());
+    executor.run(|spawner| {
+        spawner.spawn(run()).unwrap();
+    });
+}
diff --git a/examples/std/src/bin/tick.rs b/examples/std/src/bin/tick.rs
new file mode 100644
index 000000000..6f30edb34
--- /dev/null
+++ b/examples/std/src/bin/tick.rs
@@ -0,0 +1,31 @@
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+use embassy::time::{Duration, Timer};
+use embassy::util::Forever;
+use embassy_std::Executor;
+use log::*;
+
+#[embassy::task]
+async fn run() {
+    loop {
+        info!("tick");
+        Timer::after(Duration::from_secs(1)).await;
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+fn main() {
+    env_logger::builder()
+        .filter_level(log::LevelFilter::Debug)
+        .format_timestamp_nanos()
+        .init();
+
+    let executor = EXECUTOR.put(Executor::new());
+    executor.run(|spawner| {
+        spawner.spawn(run()).unwrap();
+    });
+}
diff --git a/examples/std/src/serial_port.rs b/examples/std/src/serial_port.rs
new file mode 100644
index 000000000..7ac1b1edb
--- /dev/null
+++ b/examples/std/src/serial_port.rs
@@ -0,0 +1,71 @@
+use nix::fcntl::OFlag;
+use nix::sys::termios;
+use nix::Error;
+use std::io;
+use std::os::unix::io::{AsRawFd, RawFd};
+
+pub struct SerialPort {
+    fd: RawFd,
+}
+
+impl SerialPort {
+    pub fn new<'a, P: ?Sized + nix::NixPath>(
+        path: &P,
+        baudrate: termios::BaudRate,
+    ) -> io::Result<Self> {
+        let fd = nix::fcntl::open(
+            path,
+            OFlag::O_RDWR | OFlag::O_NOCTTY | OFlag::O_NONBLOCK,
+            nix::sys::stat::Mode::empty(),
+        )
+        .map_err(to_io_error)?;
+
+        let mut cfg = termios::tcgetattr(fd).map_err(to_io_error)?;
+        cfg.input_flags = termios::InputFlags::empty();
+        cfg.output_flags = termios::OutputFlags::empty();
+        cfg.control_flags = termios::ControlFlags::empty();
+        cfg.local_flags = termios::LocalFlags::empty();
+        termios::cfmakeraw(&mut cfg);
+        cfg.input_flags |= termios::InputFlags::IGNBRK;
+        cfg.control_flags |= termios::ControlFlags::CREAD;
+        //cfg.control_flags |= termios::ControlFlags::CRTSCTS;
+        termios::cfsetospeed(&mut cfg, baudrate).map_err(to_io_error)?;
+        termios::cfsetispeed(&mut cfg, baudrate).map_err(to_io_error)?;
+        termios::cfsetspeed(&mut cfg, baudrate).map_err(to_io_error)?;
+        // Set VMIN = 1 to block until at least one character is received.
+        cfg.control_chars[termios::SpecialCharacterIndices::VMIN as usize] = 1;
+        termios::tcsetattr(fd, termios::SetArg::TCSANOW, &cfg).map_err(to_io_error)?;
+        termios::tcflush(fd, termios::FlushArg::TCIOFLUSH).map_err(to_io_error)?;
+
+        Ok(Self { fd })
+    }
+}
+
+impl AsRawFd for SerialPort {
+    fn as_raw_fd(&self) -> RawFd {
+        self.fd
+    }
+}
+
+impl io::Read for SerialPort {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        nix::unistd::read(self.fd, buf).map_err(to_io_error)
+    }
+}
+
+impl io::Write for SerialPort {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        nix::unistd::write(self.fd, buf).map_err(to_io_error)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+fn to_io_error(e: Error) -> io::Error {
+    match e {
+        Error::Sys(errno) => errno.into(),
+        e => io::Error::new(io::ErrorKind::InvalidInput, e),
+    }
+}
diff --git a/examples/std/src/tuntap.rs b/examples/std/src/tuntap.rs
new file mode 100644
index 000000000..dd453deb3
--- /dev/null
+++ b/examples/std/src/tuntap.rs
@@ -0,0 +1,225 @@
+use async_io::Async;
+use libc;
+use log::*;
+use smoltcp::wire::EthernetFrame;
+use std::io;
+use std::io::{Read, Write};
+use std::os::unix::io::{AsRawFd, RawFd};
+
+pub const SIOCGIFMTU: libc::c_ulong = 0x8921;
+pub const SIOCGIFINDEX: libc::c_ulong = 0x8933;
+pub const ETH_P_ALL: libc::c_short = 0x0003;
+pub const TUNSETIFF: libc::c_ulong = 0x400454CA;
+pub const IFF_TUN: libc::c_int = 0x0001;
+pub const IFF_TAP: libc::c_int = 0x0002;
+pub const IFF_NO_PI: libc::c_int = 0x1000;
+
+#[repr(C)]
+#[derive(Debug)]
+struct ifreq {
+    ifr_name: [libc::c_char; libc::IF_NAMESIZE],
+    ifr_data: libc::c_int, /* ifr_ifindex or ifr_mtu */
+}
+
+fn ifreq_for(name: &str) -> ifreq {
+    let mut ifreq = ifreq {
+        ifr_name: [0; libc::IF_NAMESIZE],
+        ifr_data: 0,
+    };
+    for (i, byte) in name.as_bytes().iter().enumerate() {
+        ifreq.ifr_name[i] = *byte as libc::c_char
+    }
+    ifreq
+}
+
+fn ifreq_ioctl(
+    lower: libc::c_int,
+    ifreq: &mut ifreq,
+    cmd: libc::c_ulong,
+) -> io::Result<libc::c_int> {
+    unsafe {
+        let res = libc::ioctl(lower, cmd as _, ifreq as *mut ifreq);
+        if res == -1 {
+            return Err(io::Error::last_os_error());
+        }
+    }
+
+    Ok(ifreq.ifr_data)
+}
+
+#[derive(Debug)]
+pub struct TunTap {
+    fd: libc::c_int,
+    ifreq: ifreq,
+    mtu: usize,
+}
+
+impl AsRawFd for TunTap {
+    fn as_raw_fd(&self) -> RawFd {
+        self.fd
+    }
+}
+
+impl TunTap {
+    pub fn new(name: &str) -> io::Result<TunTap> {
+        unsafe {
+            let fd = libc::open(
+                "/dev/net/tun\0".as_ptr() as *const libc::c_char,
+                libc::O_RDWR | libc::O_NONBLOCK,
+            );
+            if fd == -1 {
+                return Err(io::Error::last_os_error());
+            }
+
+            let mut ifreq = ifreq_for(name);
+            ifreq.ifr_data = IFF_TAP | IFF_NO_PI;
+            ifreq_ioctl(fd, &mut ifreq, TUNSETIFF)?;
+
+            let socket = libc::socket(libc::AF_INET, libc::SOCK_DGRAM, libc::IPPROTO_IP);
+            if socket == -1 {
+                return Err(io::Error::last_os_error());
+            }
+
+            let ip_mtu = ifreq_ioctl(socket, &mut ifreq, SIOCGIFMTU);
+            libc::close(socket);
+            let ip_mtu = ip_mtu? as usize;
+
+            // SIOCGIFMTU returns the IP MTU (typically 1500 bytes.)
+            // smoltcp counts the entire Ethernet packet in the MTU, so add the Ethernet header size to it.
+            let mtu = ip_mtu + EthernetFrame::<&[u8]>::header_len();
+
+            Ok(TunTap { fd, mtu, ifreq })
+        }
+    }
+}
+
+impl Drop for TunTap {
+    fn drop(&mut self) {
+        unsafe {
+            libc::close(self.fd);
+        }
+    }
+}
+
+impl io::Read for TunTap {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let len = unsafe { libc::read(self.fd, buf.as_mut_ptr() as *mut libc::c_void, buf.len()) };
+        if len == -1 {
+            Err(io::Error::last_os_error())
+        } else {
+            Ok(len as usize)
+        }
+    }
+}
+
+impl io::Write for TunTap {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        let len = unsafe { libc::write(self.fd, buf.as_ptr() as *mut libc::c_void, buf.len()) };
+        if len == -1 {
+            Err(io::Error::last_os_error())
+        } else {
+            Ok(len as usize)
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+pub struct TunTapDevice {
+    device: Async<TunTap>,
+    waker: Option<Waker>,
+}
+
+impl TunTapDevice {
+    pub fn new(name: &str) -> io::Result<TunTapDevice> {
+        Ok(Self {
+            device: Async::new(TunTap::new(name)?)?,
+            waker: None,
+        })
+    }
+}
+
+use core::task::Waker;
+use embassy_net::{DeviceCapabilities, LinkState, Packet, PacketBox, PacketBoxExt, PacketBuf};
+use std::task::Context;
+
+impl crate::Device for TunTapDevice {
+    fn is_transmit_ready(&mut self) -> bool {
+        true
+    }
+
+    fn transmit(&mut self, pkt: PacketBuf) {
+        // todo handle WouldBlock
+        match self.device.get_mut().write(&pkt) {
+            Ok(_) => {}
+            Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
+                info!("transmit WouldBlock");
+            }
+            Err(e) => panic!("transmit error: {:?}", e),
+        }
+    }
+
+    fn receive(&mut self) -> Option<PacketBuf> {
+        let mut pkt = PacketBox::new(Packet::new()).unwrap();
+        loop {
+            match self.device.get_mut().read(&mut pkt[..]) {
+                Ok(n) => {
+                    return Some(pkt.slice(0..n));
+                }
+                Err(e) if e.kind() == io::ErrorKind::WouldBlock => {
+                    let ready = if let Some(w) = self.waker.as_ref() {
+                        let mut cx = Context::from_waker(w);
+                        let ready = self.device.poll_readable(&mut cx).is_ready();
+                        ready
+                    } else {
+                        false
+                    };
+                    if !ready {
+                        return None;
+                    }
+                }
+                Err(e) => panic!("read error: {:?}", e),
+            }
+        }
+    }
+
+    fn register_waker(&mut self, w: &Waker) {
+        match self.waker {
+            // Optimization: If both the old and new Wakers wake the same task, we can simply
+            // keep the old waker, skipping the clone. (In most executor implementations,
+            // cloning a waker is somewhat expensive, comparable to cloning an Arc).
+            Some(ref w2) if (w2.will_wake(w)) => {}
+            _ => {
+                // clone the new waker and store it
+                if let Some(old_waker) = core::mem::replace(&mut self.waker, Some(w.clone())) {
+                    // We had a waker registered for another task. Wake it, so the other task can
+                    // reregister itself if it's still interested.
+                    //
+                    // If two tasks are waiting on the same thing concurrently, this will cause them
+                    // to wake each other in a loop fighting over this WakerRegistration. This wastes
+                    // CPU but things will still work.
+                    //
+                    // If the user wants to have two tasks waiting on the same thing they should use
+                    // a more appropriate primitive that can store multiple wakers.
+                    old_waker.wake()
+                }
+            }
+        }
+    }
+
+    fn capabilities(&mut self) -> DeviceCapabilities {
+        let mut caps = DeviceCapabilities::default();
+        caps.max_transmission_unit = self.device.get_ref().mtu;
+        caps
+    }
+
+    fn link_state(&mut self) -> LinkState {
+        LinkState::Up
+    }
+
+    fn ethernet_address(&mut self) -> [u8; 6] {
+        [0x02, 0x03, 0x04, 0x05, 0x06, 0x07]
+    }
+}
diff --git a/examples/stm32f4/.cargo/config.toml b/examples/stm32f4/.cargo/config.toml
new file mode 100644
index 000000000..8704a9ba5
--- /dev/null
+++ b/examples/stm32f4/.cargo/config.toml
@@ -0,0 +1,21 @@
+[unstable]
+build-std = ["core"]
+
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+# replace STM32F429ZITx with your chip as listed in `probe-run --list-chips`
+runner = "probe-run --chip STM32F429ZITx"
+
+rustflags = [
+  # LLD (shipped with the Rust toolchain) is used as the default linker
+  "-C", "link-arg=--nmagic",
+  "-C", "link-arg=-Tlink.x",
+  "-C", "link-arg=-Tdefmt.x",
+
+  # Code-size optimizations.
+  "-Z", "trap-unreachable=no",
+  "-C", "inline-threshold=5",
+  "-C", "no-vectorize-loops",
+]
+
+[build]
+target = "thumbv7em-none-eabi"
diff --git a/examples/stm32f4/Cargo.toml b/examples/stm32f4/Cargo.toml
new file mode 100644
index 000000000..c5c8d9ae6
--- /dev/null
+++ b/examples/stm32f4/Cargo.toml
@@ -0,0 +1,35 @@
+[package]
+authors = ["Dario Nieuwenhuis <[email protected]>"]
+edition = "2018"
+name = "embassy-stm32f4-examples"
+version = "0.1.0"
+resolver = "2"
+
+[features]
+default = [
+    "defmt-default",
+]
+defmt-default = []
+defmt-trace = []
+defmt-debug = []
+defmt-info = []
+defmt-warn = []
+defmt-error = []
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-trace"] }
+embassy-traits = { version = "0.1.0", path = "../../embassy-traits", features = ["defmt"] }
+embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["defmt", "defmt-trace", "stm32f429zi"]  }
+embassy-extras = {version = "0.1.0", path = "../../embassy-extras" }
+stm32f4 = { version = "0.13", features = ["stm32f429"] }
+
+defmt = "0.2.0"
+defmt-rtt = "0.2.0"
+
+cortex-m = "0.7.1"
+cortex-m-rt = "0.6.14"
+embedded-hal    = { version = "0.2.4" }
+panic-probe = { version = "0.2.0", features= ["print-defmt"] }
+futures = { version = "0.3.8", default-features = false, features = ["async-await"] }
+rtt-target = { version = "0.3", features = ["cortex-m"] }
+heapless = "0.7"
\ No newline at end of file
diff --git a/examples/stm32f4/build.rs b/examples/stm32f4/build.rs
new file mode 100644
index 000000000..d534cc3df
--- /dev/null
+++ b/examples/stm32f4/build.rs
@@ -0,0 +1,31 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+}
diff --git a/examples/stm32f4/memory.x b/examples/stm32f4/memory.x
new file mode 100644
index 000000000..f21e32572
--- /dev/null
+++ b/examples/stm32f4/memory.x
@@ -0,0 +1,7 @@
+MEMORY
+{
+  /* NOTE 1 K = 1 KiBi = 1024 bytes */
+  /* These values correspond to the STM32F429ZI */
+  FLASH : ORIGIN = 0x08000000, LENGTH = 2048K
+  RAM : ORIGIN = 0x20000000, LENGTH = 192K
+}
diff --git a/examples/stm32f4/src/bin/blinky.rs b/examples/stm32f4/src/bin/blinky.rs
new file mode 100644
index 000000000..7590764d8
--- /dev/null
+++ b/examples/stm32f4/src/bin/blinky.rs
@@ -0,0 +1,54 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_stm32::gpio::{Level, Output};
+use embedded_hal::digital::v2::OutputPin;
+use example_common::*;
+
+use cortex_m_rt::entry;
+use stm32f4::stm32f429 as pac;
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbg_sleep().set_bit();
+        w.dbg_standby().set_bit();
+        w.dbg_stop().set_bit()
+    });
+    pp.RCC.ahb1enr.modify(|_, w| w.dma1en().enabled());
+
+    pp.RCC.ahb1enr.modify(|_, w| {
+        w.gpioaen().enabled();
+        w.gpioben().enabled();
+        w.gpiocen().enabled();
+        w.gpioden().enabled();
+        w.gpioeen().enabled();
+        w.gpiofen().enabled();
+        w
+    });
+
+    let p = embassy_stm32::init(Default::default());
+
+    let mut led = Output::new(p.PB7, Level::High);
+
+    loop {
+        info!("high");
+        led.set_high().unwrap();
+        cortex_m::asm::delay(10_000_000);
+
+        info!("low");
+        led.set_low().unwrap();
+        cortex_m::asm::delay(10_000_000);
+    }
+}
diff --git a/examples/stm32f4/src/bin/button.rs b/examples/stm32f4/src/bin/button.rs
new file mode 100644
index 000000000..1ee99f527
--- /dev/null
+++ b/examples/stm32f4/src/bin/button.rs
@@ -0,0 +1,59 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_stm32::gpio::{Input, Level, Output, Pull};
+use embedded_hal::digital::v2::{InputPin, OutputPin};
+use example_common::*;
+
+use cortex_m_rt::entry;
+use stm32f4::stm32f429 as pac;
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbg_sleep().set_bit();
+        w.dbg_standby().set_bit();
+        w.dbg_stop().set_bit()
+    });
+    pp.RCC.ahb1enr.modify(|_, w| w.dma1en().enabled());
+
+    pp.RCC.ahb1enr.modify(|_, w| {
+        w.gpioaen().enabled();
+        w.gpioben().enabled();
+        w.gpiocen().enabled();
+        w.gpioden().enabled();
+        w.gpioeen().enabled();
+        w.gpiofen().enabled();
+        w
+    });
+
+    let p = embassy_stm32::init(Default::default());
+
+    let button = Input::new(p.PC13, Pull::Down);
+    let mut led1 = Output::new(p.PB0, Level::High);
+    let _led2 = Output::new(p.PB7, Level::High);
+    let mut led3 = Output::new(p.PB14, Level::High);
+
+    loop {
+        if button.is_high().unwrap() {
+            info!("high");
+            led1.set_high().unwrap();
+            led3.set_low().unwrap();
+        } else {
+            info!("low");
+            led1.set_low().unwrap();
+            led3.set_high().unwrap();
+        }
+    }
+}
diff --git a/examples/stm32f4/src/bin/button_exti.rs b/examples/stm32f4/src/bin/button_exti.rs
new file mode 100644
index 000000000..8fc889dad
--- /dev/null
+++ b/examples/stm32f4/src/bin/button_exti.rs
@@ -0,0 +1,83 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy::executor::Executor;
+use embassy::time::Clock;
+use embassy::util::Forever;
+use embassy_stm32::exti::ExtiInput;
+use embassy_stm32::gpio::{Input, Pull};
+use embassy_traits::gpio::{WaitForFallingEdge, WaitForRisingEdge};
+use example_common::*;
+
+use cortex_m_rt::entry;
+use stm32f4::stm32f429 as pac;
+
+#[embassy::task]
+async fn main_task() {
+    let p = embassy_stm32::init(Default::default());
+
+    let button = Input::new(p.PC13, Pull::Down);
+    let mut button = ExtiInput::new(button, p.EXTI13);
+
+    info!("Press the USER button...");
+
+    loop {
+        button.wait_for_rising_edge().await;
+        info!("Pressed!");
+        button.wait_for_falling_edge().await;
+        info!("Released!");
+    }
+}
+
+struct ZeroClock;
+
+impl Clock for ZeroClock {
+    fn now(&self) -> u64 {
+        0
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbg_sleep().set_bit();
+        w.dbg_standby().set_bit();
+        w.dbg_stop().set_bit()
+    });
+    pp.RCC.ahb1enr.modify(|_, w| w.dma1en().enabled());
+
+    pp.RCC.ahb1enr.modify(|_, w| {
+        w.gpioaen().enabled();
+        w.gpioben().enabled();
+        w.gpiocen().enabled();
+        w.gpioden().enabled();
+        w.gpioeen().enabled();
+        w.gpiofen().enabled();
+        w
+    });
+    pp.RCC.apb2enr.modify(|_, w| {
+        w.syscfgen().enabled();
+        w
+    });
+
+    unsafe { embassy::time::set_clock(&ZeroClock) };
+
+    let executor = EXECUTOR.put(Executor::new());
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(main_task()));
+    })
+}
diff --git a/examples/stm32f4/src/bin/spi.rs b/examples/stm32f4/src/bin/spi.rs
new file mode 100644
index 000000000..af0d57412
--- /dev/null
+++ b/examples/stm32f4/src/bin/spi.rs
@@ -0,0 +1,71 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+
+use embassy_stm32::gpio::{Level, Output};
+use embedded_hal::digital::v2::OutputPin;
+use example_common::*;
+
+use cortex_m_rt::entry;
+use embassy_stm32::spi::{Config, Spi};
+use embassy_stm32::time::Hertz;
+use embedded_hal::blocking::spi::Transfer;
+use stm32f4::stm32f429 as pac;
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World, dude!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbg_sleep().set_bit();
+        w.dbg_standby().set_bit();
+        w.dbg_stop().set_bit()
+    });
+    pp.RCC.ahb1enr.modify(|_, w| w.dma1en().set_bit());
+
+    pp.RCC.apb1enr.modify(|_, w| {
+        w.spi3en().enabled();
+        w
+    });
+
+    pp.RCC.ahb1enr.modify(|_, w| {
+        w.gpioaen().enabled();
+        w.gpioben().enabled();
+        w.gpiocen().enabled();
+        w.gpioden().enabled();
+        w.gpioeen().enabled();
+        w.gpiofen().enabled();
+        w
+    });
+
+    let p = embassy_stm32::init(Default::default());
+
+    let mut spi = Spi::new(
+        Hertz(16_000_000),
+        p.SPI3,
+        p.PC10,
+        p.PC12,
+        p.PC11,
+        Hertz(1_000_000),
+        Config::default(),
+    );
+
+    let mut cs = Output::new(p.PE0, Level::High);
+
+    loop {
+        let mut buf = [0x0A; 4];
+        unwrap!(cs.set_low());
+        unwrap!(spi.transfer(&mut buf));
+        unwrap!(cs.set_high());
+        info!("xfer {=[u8]:x}", buf);
+    }
+}
diff --git a/examples/stm32f4/src/bin/usart.rs b/examples/stm32f4/src/bin/usart.rs
new file mode 100644
index 000000000..f7b66f86b
--- /dev/null
+++ b/examples/stm32f4/src/bin/usart.rs
@@ -0,0 +1,86 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use cortex_m::prelude::_embedded_hal_blocking_serial_Write;
+use embassy::executor::Executor;
+use embassy::time::Clock;
+use embassy::util::Forever;
+use embassy_stm32::usart::{Config, Uart};
+use example_common::*;
+
+use cortex_m_rt::entry;
+use stm32f4::stm32f429 as pac;
+
+#[embassy::task]
+async fn main_task() {
+    let p = embassy_stm32::init(Default::default());
+
+    let config = Config::default();
+    let mut usart = Uart::new(p.USART3, p.PD9, p.PD8, config, 16_000_000);
+
+    usart.bwrite_all(b"Hello Embassy World!\r\n").unwrap();
+    info!("wrote Hello, starting echo");
+
+    let mut buf = [0u8; 1];
+    loop {
+        usart.read(&mut buf).unwrap();
+        usart.bwrite_all(&buf).unwrap();
+    }
+}
+
+struct ZeroClock;
+
+impl Clock for ZeroClock {
+    fn now(&self) -> u64 {
+        0
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbg_sleep().set_bit();
+        w.dbg_standby().set_bit();
+        w.dbg_stop().set_bit()
+    });
+    pp.RCC.ahb1enr.modify(|_, w| w.dma1en().enabled());
+
+    pp.RCC.ahb1enr.modify(|_, w| {
+        w.gpioaen().enabled();
+        w.gpioben().enabled();
+        w.gpiocen().enabled();
+        w.gpioden().enabled();
+        w.gpioeen().enabled();
+        w.gpiofen().enabled();
+        w
+    });
+    pp.RCC.apb2enr.modify(|_, w| {
+        w.syscfgen().enabled();
+        w
+    });
+    pp.RCC.apb1enr.modify(|_, w| {
+        w.usart3en().enabled();
+        w
+    });
+
+    unsafe { embassy::time::set_clock(&ZeroClock) };
+
+    let executor = EXECUTOR.put(Executor::new());
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(main_task()));
+    })
+}
diff --git a/examples/stm32f4/src/bin/usart_dma.rs b/examples/stm32f4/src/bin/usart_dma.rs
new file mode 100644
index 000000000..fae05b607
--- /dev/null
+++ b/examples/stm32f4/src/bin/usart_dma.rs
@@ -0,0 +1,90 @@
+#![no_std]
+#![no_main]
+#![feature(trait_alias)]
+#![feature(min_type_alias_impl_trait)]
+#![feature(impl_trait_in_bindings)]
+#![feature(type_alias_impl_trait)]
+#![allow(incomplete_features)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use core::fmt::Write;
+use cortex_m_rt::entry;
+use embassy::executor::Executor;
+use embassy::time::Clock;
+use embassy::util::Forever;
+use embassy_stm32::usart::{Config, Uart};
+use example_common::*;
+use heapless::String;
+use stm32f4::stm32f429 as pac;
+
+#[embassy::task]
+async fn main_task() {
+    let mut p = embassy_stm32::init(Default::default());
+
+    let config = Config::default();
+    let mut usart = Uart::new(p.USART3, p.PD9, p.PD8, config, 16_000_000);
+
+    for n in 0u32.. {
+        let mut s: String<128> = String::new();
+        core::write!(&mut s, "Hello DMA World {}!\r\n", n).unwrap();
+
+        usart
+            .write_dma(&mut p.DMA1_CH3, s.as_bytes())
+            .await
+            .unwrap();
+        info!("wrote DMA");
+    }
+}
+
+struct ZeroClock;
+
+impl Clock for ZeroClock {
+    fn now(&self) -> u64 {
+        0
+    }
+}
+
+static EXECUTOR: Forever<Executor> = Forever::new();
+
+#[entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let pp = pac::Peripherals::take().unwrap();
+
+    pp.DBGMCU.cr.modify(|_, w| {
+        w.dbg_sleep().set_bit();
+        w.dbg_standby().set_bit();
+        w.dbg_stop().set_bit()
+    });
+    pp.RCC.ahb1enr.modify(|_, w| w.dma1en().enabled());
+
+    pp.RCC.ahb1enr.modify(|_, w| {
+        w.gpioaen().enabled();
+        w.gpioben().enabled();
+        w.gpiocen().enabled();
+        w.gpioden().enabled();
+        w.gpioeen().enabled();
+        w.gpiofen().enabled();
+        w.dma1en().enabled();
+        w.dma2en().enabled();
+        w
+    });
+    pp.RCC.apb2enr.modify(|_, w| {
+        w.syscfgen().enabled();
+        w
+    });
+    pp.RCC.apb1enr.modify(|_, w| {
+        w.usart3en().enabled();
+        w
+    });
+
+    unsafe { embassy::time::set_clock(&ZeroClock) };
+
+    let executor = EXECUTOR.put(Executor::new());
+
+    executor.run(|spawner| {
+        unwrap!(spawner.spawn(main_task()));
+    })
+}
diff --git a/examples/stm32f4/src/example_common.rs b/examples/stm32f4/src/example_common.rs
new file mode 100644
index 000000000..54d633837
--- /dev/null
+++ b/examples/stm32f4/src/example_common.rs
@@ -0,0 +1,17 @@
+#![macro_use]
+
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+pub use defmt::*;
+
+use core::sync::atomic::{AtomicUsize, Ordering};
+
+defmt::timestamp! {"{=u64}", {
+        static COUNT: AtomicUsize = AtomicUsize::new(0);
+        // NOTE(no-CAS) `timestamps` runs with interrupts disabled
+        let n = COUNT.load(Ordering::Relaxed);
+        COUNT.store(n + 1, Ordering::Relaxed);
+        n as u64
+    }
+}