Add some examples.

- usart works
- dac works
- rng gets stuck on while loop
- usb_serial works, but cannot test due to lack of user usb port
- adc needs work and does not work yet

6 files changed, 252 insertions, 0 deletions

diff --git a/examples/stm32u0/Cargo.toml b/examples/stm32u0/Cargo.toml
index af3d7ff61..8219cb038 100644
--- a/examples/stm32u0/Cargo.toml
+++ b/examples/stm32u0/Cargo.toml
@@ -10,6 +10,7 @@ embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = [
 embassy-sync = { version = "0.5.0", path = "../../embassy-sync", features = ["defmt"] }
 embassy-executor = { version = "0.5.0", path = "../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "defmt", "integrated-timers"] }
 embassy-time = { version = "0.3.0", path = "../../embassy-time", features = ["defmt", "defmt-timestamp-uptime", "tick-hz-32_768"] }
+embassy-usb = { version = "0.1.0", path = "../../embassy-usb", default-features = false, features = ["defmt"] }
 
 defmt = "0.3"
 defmt-rtt = "0.4"
@@ -21,5 +22,7 @@ panic-probe = { version = "0.3", features = ["print-defmt"] }
 futures = { version = "0.3.17", default-features = false, features = ["async-await"] }
 heapless = { version = "0.8", default-features = false }
 
+micromath = "2.0.0"
+
 [profile.release]
 debug = 2
diff --git a/examples/stm32u0/src/bin/adc.rs b/examples/stm32u0/src/bin/adc.rs
new file mode 100644
index 000000000..f7145b85d
--- /dev/null
+++ b/examples/stm32u0/src/bin/adc.rs
@@ -0,0 +1,33 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_stm32::adc::{Adc, Resolution};
+use embassy_stm32::Config;
+use embassy_time::Duration;
+use {defmt_rtt as _, panic_probe as _};
+
+#[cortex_m_rt::entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.mux.adcsel = mux::Adcsel::SYS;
+    }
+    let p = embassy_stm32::init(config);
+
+    let mut adc = Adc::new(p.ADC1);
+    let mut temp = adc.enable_temperature();
+    adc.set_resolution(Resolution::BITS8);
+    let mut channel = p.PC0;
+
+    loop {
+        let v = adc.read(&mut channel);
+        info!("--> {}", v);
+        let v = adc.read(&mut temp);
+        info!("Temp: --> {}", v);
+        embassy_time::block_for(Duration::from_millis(1000));
+    }
+}
diff --git a/examples/stm32u0/src/bin/dac.rs b/examples/stm32u0/src/bin/dac.rs
new file mode 100644
index 000000000..fdbf1d374
--- /dev/null
+++ b/examples/stm32u0/src/bin/dac.rs
@@ -0,0 +1,35 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_stm32::dac::{DacCh1, Value};
+use embassy_stm32::dma::NoDma;
+use {defmt_rtt as _, panic_probe as _};
+
+#[cortex_m_rt::entry]
+fn main() -> ! {
+    let p = embassy_stm32::init(Default::default());
+    info!("Hello World!");
+
+    let mut dac = DacCh1::new(p.DAC1, NoDma, p.PA4);
+
+    loop {
+        for v in 0..=255 {
+            dac.set(Value::Bit8(to_sine_wave(v)));
+        }
+    }
+}
+
+use micromath::F32Ext;
+
+fn to_sine_wave(v: u8) -> u8 {
+    if v >= 128 {
+        // top half
+        let r = 3.14 * ((v - 128) as f32 / 128.0);
+        (r.sin() * 128.0 + 127.0) as u8
+    } else {
+        // bottom half
+        let r = 3.14 + 3.14 * (v as f32 / 128.0);
+        (r.sin() * 128.0 + 127.0) as u8
+    }
+}
diff --git a/examples/stm32u0/src/bin/rng.rs b/examples/stm32u0/src/bin/rng.rs
new file mode 100644
index 000000000..9b4c2537e
--- /dev/null
+++ b/examples/stm32u0/src/bin/rng.rs
@@ -0,0 +1,41 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_executor::Spawner;
+use embassy_stm32::rng::Rng;
+use embassy_stm32::{bind_interrupts, peripherals, rng, Config};
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    RNG_CRYP => rng::InterruptHandler<peripherals::RNG>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hsi = true;
+        config.rcc.pll = Some(Pll {
+            source: PllSource::HSI, // 16 MHz
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL7, // 16 * 7 = 112 MHz
+            divp: None,
+            divq: None,
+            divr: Some(PllRDiv::DIV2), // 112 / 2 = 56 MHz
+        });
+        config.rcc.sys = Sysclk::PLL1_R;
+    }
+
+    let p = embassy_stm32::init(config);
+
+    info!("Hello World!");
+
+    let mut rng = Rng::new(p.RNG, Irqs);
+    info!("Hello World 2!");
+
+    let mut buf = [0u8; 16];
+    unwrap!(rng.async_fill_bytes(&mut buf).await);
+    info!("random bytes: {:02x}", buf);
+}
diff --git a/examples/stm32u0/src/bin/usart.rs b/examples/stm32u0/src/bin/usart.rs
new file mode 100644
index 000000000..1fcf0029a
--- /dev/null
+++ b/examples/stm32u0/src/bin/usart.rs
@@ -0,0 +1,31 @@
+#![no_std]
+#![no_main]
+
+use defmt::*;
+use embassy_stm32::dma::NoDma;
+use embassy_stm32::usart::{Config, Uart};
+use embassy_stm32::{bind_interrupts, peripherals, usart};
+use {defmt_rtt as _, panic_probe as _};
+
+bind_interrupts!(struct Irqs {
+    USART2_LPUART2 => usart::InterruptHandler<peripherals::USART2>;
+});
+
+#[cortex_m_rt::entry]
+fn main() -> ! {
+    info!("Hello World!");
+
+    let p = embassy_stm32::init(Default::default());
+
+    let config = Config::default();
+    let mut usart = Uart::new(p.USART2, p.PA3, p.PA2, Irqs, NoDma, NoDma, config).unwrap();
+
+    unwrap!(usart.blocking_write(b"Hello Embassy World!\r\n"));
+    info!("wrote Hello, starting echo");
+
+    let mut buf = [0u8; 1];
+    loop {
+        unwrap!(usart.blocking_read(&mut buf));
+        unwrap!(usart.blocking_write(&buf));
+    }
+}
diff --git a/examples/stm32u0/src/bin/usb_serial.rs b/examples/stm32u0/src/bin/usb_serial.rs
new file mode 100644
index 000000000..9b38fd5dc
--- /dev/null
+++ b/examples/stm32u0/src/bin/usb_serial.rs
@@ -0,0 +1,109 @@
+#![no_std]
+#![no_main]
+
+use defmt::{panic, *};
+use defmt_rtt as _; // global logger
+use embassy_executor::Spawner;
+use embassy_stm32::usb::{Driver, Instance};
+use embassy_stm32::{bind_interrupts, peripherals, usb, Config};
+use embassy_usb::class::cdc_acm::{CdcAcmClass, State};
+use embassy_usb::driver::EndpointError;
+use embassy_usb::Builder;
+use futures::future::join;
+use panic_probe as _;
+
+bind_interrupts!(struct Irqs {
+    USB_DRD_FS => usb::InterruptHandler<peripherals::USB>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = Config::default();
+    {
+        use embassy_stm32::rcc::*;
+        config.rcc.hsi = true;
+        config.rcc.pll = Some(Pll {
+            source: PllSource::HSI, // 16 MHz
+            prediv: PllPreDiv::DIV1,
+            mul: PllMul::MUL7,
+            divp: None,
+            divq: None,
+            divr: Some(PllRDiv::DIV2), // 56 MHz
+        });
+        config.rcc.sys = Sysclk::PLL1_R;
+        config.rcc.hsi48 = Some(Hsi48Config { sync_from_usb: true }); // needed for USB
+        config.rcc.mux.clk48sel = mux::Clk48sel::HSI48; // USB uses ICLK
+    }
+
+    let p = embassy_stm32::init(config);
+
+    info!("Hello World!");
+
+    // Create the driver, from the HAL.
+    let driver = Driver::new(p.USB, Irqs, p.PA12, p.PA11);
+
+    // Create embassy-usb Config
+    let config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    //config.max_packet_size_0 = 64;
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    // It needs some buffers for building the descriptors.
+    let mut config_descriptor = [0; 256];
+    let mut bos_descriptor = [0; 256];
+    let mut control_buf = [0; 7];
+
+    let mut state = State::new();
+
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut [], // no msos descriptors
+        &mut control_buf,
+    );
+
+    // Create classes on the builder.
+    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);
+
+    // Build the builder.
+    let mut usb = builder.build();
+
+    // Run the USB device.
+    let usb_fut = usb.run();
+
+    // Do stuff with the class!
+    let echo_fut = async {
+        loop {
+            class.wait_connection().await;
+            info!("Connected");
+            let _ = echo(&mut class).await;
+            info!("Disconnected");
+        }
+    };
+
+    // Run everything concurrently.
+    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
+    join(usb_fut, echo_fut).await;
+}
+
+struct Disconnected {}
+
+impl From<EndpointError> for Disconnected {
+    fn from(val: EndpointError) -> Self {
+        match val {
+            EndpointError::BufferOverflow => panic!("Buffer overflow"),
+            EndpointError::Disabled => Disconnected {},
+        }
+    }
+}
+
+async fn echo<'d, T: Instance + 'd>(class: &mut CdcAcmClass<'d, Driver<'d, T>>) -> Result<(), Disconnected> {
+    let mut buf = [0; 64];
+    loop {
+        let n = class.read_packet(&mut buf).await?;
+        let data = &buf[..n];
+        info!("data: {:x}", data);
+        class.write_packet(data).await?;
+    }
+}