Ring-buffered uart rx with one-period overrun detection

tests/stm32/Cargo.toml

@@ -33,6 +33,8 @@ embedded-hal = "0.2.6"
 embedded-hal-1 = { package = "embedded-hal", version = "=1.0.0-alpha.10" }
 embedded-hal-async = { version = "=0.2.0-alpha.1" }
 panic-probe = { version = "0.3.0", features = ["print-defmt"] }
+rand_core = { version = "0.6", default-features = false }
+rand_chacha = { version = "0.3", default-features = false }
 
 chrono = { version = "^0.4", default-features = false, optional = true}
 

tests/stm32/src/bin/usart_rx_ringbuffered.rs

@@ -0,0 +1,188 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[path = "../example_common.rs"]
+mod example_common;
+use embassy_executor::Spawner;
+use embassy_stm32::interrupt;
+use embassy_stm32::usart::{Config, DataBits, Parity, RingBufferedUartRx, StopBits, Uart, UartTx};
+use embassy_time::{Duration, Timer};
+use example_common::*;
+use rand_chacha::ChaCha8Rng;
+use rand_core::{RngCore, SeedableRng};
+
+#[cfg(feature = "stm32f103c8")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::USART1;
+    pub type TxDma = embassy_stm32::peripherals::DMA1_CH4;
+    pub type RxDma = embassy_stm32::peripherals::DMA1_CH5;
+}
+#[cfg(feature = "stm32g491re")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::USART1;
+    pub type TxDma = embassy_stm32::peripherals::DMA1_CH1;
+    pub type RxDma = embassy_stm32::peripherals::DMA1_CH2;
+}
+#[cfg(feature = "stm32g071rb")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::USART1;
+    pub type TxDma = embassy_stm32::peripherals::DMA1_CH1;
+    pub type RxDma = embassy_stm32::peripherals::DMA1_CH2;
+}
+#[cfg(feature = "stm32f429zi")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::USART2;
+    pub type TxDma = embassy_stm32::peripherals::DMA1_CH6;
+    pub type RxDma = embassy_stm32::peripherals::DMA1_CH5;
+}
+#[cfg(feature = "stm32wb55rg")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::LPUART1;
+    pub type TxDma = embassy_stm32::peripherals::DMA1_CH1;
+    pub type RxDma = embassy_stm32::peripherals::DMA1_CH2;
+}
+#[cfg(feature = "stm32h755zi")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::USART1;
+    pub type TxDma = embassy_stm32::peripherals::DMA1_CH0;
+    pub type RxDma = embassy_stm32::peripherals::DMA1_CH1;
+}
+#[cfg(feature = "stm32u585ai")]
+mod board {
+    pub type Uart = embassy_stm32::peripherals::USART3;
+    pub type TxDma = embassy_stm32::peripherals::GPDMA1_CH0;
+    pub type RxDma = embassy_stm32::peripherals::GPDMA1_CH1;
+}
+
+const ONE_BYTE_DURATION_US: u32 = 9_000_000 / 115200;
+
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    let p = embassy_stm32::init(config());
+    info!("Hello World!");
+
+    // Arduino pins D0 and D1
+    // They're connected together with a 1K resistor.
+    #[cfg(feature = "stm32f103c8")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) = (
+        p.PA9,
+        p.PA10,
+        p.USART1,
+        interrupt::take!(USART1),
+        p.DMA1_CH4,
+        p.DMA1_CH5,
+    );
+    #[cfg(feature = "stm32g491re")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) =
+        (p.PC4, p.PC5, p.USART1, interrupt::take!(USART1), p.DMA1_CH1, p.DMA1_CH2);
+    #[cfg(feature = "stm32g071rb")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) =
+        (p.PC4, p.PC5, p.USART1, interrupt::take!(USART1), p.DMA1_CH1, p.DMA1_CH2);
+    #[cfg(feature = "stm32f429zi")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) =
+        (p.PA2, p.PA3, p.USART2, interrupt::take!(USART2), p.DMA1_CH6, p.DMA1_CH5);
+    #[cfg(feature = "stm32wb55rg")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) = (
+        p.PA2,
+        p.PA3,
+        p.LPUART1,
+        interrupt::take!(LPUART1),
+        p.DMA1_CH1,
+        p.DMA1_CH2,
+    );
+    #[cfg(feature = "stm32h755zi")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) =
+        (p.PB6, p.PB7, p.USART1, interrupt::take!(USART1), p.DMA1_CH0, p.DMA1_CH1);
+    #[cfg(feature = "stm32u585ai")]
+    let (tx, rx, usart, irq, tx_dma, rx_dma) = (
+        p.PD8,
+        p.PD9,
+        p.USART3,
+        interrupt::take!(USART3),
+        p.GPDMA1_CH0,
+        p.GPDMA1_CH1,
+    );
+
+    // To run this test, use the saturating_serial test utility to saturate the serial port
+
+    let mut config = Config::default();
+    config.baudrate = 115200;
+    config.data_bits = DataBits::DataBits8;
+    config.stop_bits = StopBits::STOP1;
+    config.parity = Parity::ParityNone;
+
+    let usart = Uart::new(usart, rx, tx, irq, tx_dma, rx_dma, config);
+    let (tx, rx) = usart.split();
+    static mut DMA_BUF: [u8; 64] = [0; 64];
+    let dma_buf = unsafe { DMA_BUF.as_mut() };
+    let rx = rx.into_ring_buffered(dma_buf);
+
+    info!("Spawning tasks");
+    spawner.spawn(transmit_task(tx)).unwrap();
+    spawner.spawn(receive_task(rx)).unwrap();
+}
+
+#[embassy_executor::task]
+async fn transmit_task(mut tx: UartTx<'static, board::Uart, board::TxDma>) {
+    let mut rng = ChaCha8Rng::seed_from_u64(1337);
+
+    info!("Starting random transmissions into void...");
+
+    let mut i: u8 = 0;
+    loop {
+        let mut buf = [0; 32];
+        let len = 1 + (rng.next_u32() as usize % (buf.len() - 1));
+        for b in &mut buf[..len] {
+            *b = i;
+            i = i.wrapping_add(1);
+        }
+
+        tx.write(&buf[..len]).await.unwrap();
+        Timer::after(Duration::from_micros((rng.next_u32() % 10000) as _)).await;
+
+        //i += 1;
+        //if i % 1000 == 0 {
+        //    trace!("Wrote {} times", i);
+        //}
+    }
+}
+
+#[embassy_executor::task]
+async fn receive_task(mut rx: RingBufferedUartRx<'static, board::Uart, board::RxDma>) {
+    info!("Ready to receive...");
+
+    let mut rng = ChaCha8Rng::seed_from_u64(1337);
+
+    let mut i = 0;
+    let mut expected: Option<u8> = None;
+    loop {
+        let mut buf = [0; 100];
+        let max_len = 1 + (rng.next_u32() as usize % (buf.len() - 1));
+        let received = rx.read(&mut buf[..max_len]).await.unwrap();
+
+        if expected.is_none() {
+            info!("Test started");
+            expected = Some(buf[0]);
+        }
+
+        for byte in &buf[..received] {
+            if byte != &expected.unwrap() {
+                error!("Test fail! received {}, expected {}", *byte, expected.unwrap());
+                cortex_m::asm::bkpt();
+                return;
+            }
+            expected = Some(expected.unwrap().wrapping_add(1));
+        }
+
+        if received < max_len {
+            let byte_count = rng.next_u32() % 64;
+            Timer::after(Duration::from_micros((byte_count * ONE_BYTE_DURATION_US) as _)).await;
+        }
+
+        i += 1;
+        if i % 1000 == 0 {
+            trace!("Read {} times", i);
+        }
+    }
+}

tests/utils/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "test-utils"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rand = "0.8"
+serial = "0.4"

tests/utils/src/bin/saturate_serial.rs

@@ -0,0 +1,52 @@
+use std::path::Path;
+use std::time::Duration;
+use std::{env, io, thread};
+
+use rand::random;
+use serial::SerialPort;
+
+pub fn main() {
+    if let Some(port_name) = env::args().nth(1) {
+        let sleep = env::args().position(|x| x == "--sleep").is_some();
+
+        println!("Saturating port {:?} with 115200 8N1", port_name);
+        println!("Sleep: {}", sleep);
+        let mut port = serial::open(&port_name).unwrap();
+        if saturate(&mut port, sleep).is_err() {
+            eprintln!("Unable to saturate port");
+        }
+    } else {
+        let path = env::args().next().unwrap();
+        let basepath = Path::new(&path).with_extension("");
+        let basename = basepath.file_name().unwrap();
+        eprintln!("USAGE: {} <port-name>", basename.to_string_lossy());
+    }
+}
+
+fn saturate<T: SerialPort>(port: &mut T, sleep: bool) -> io::Result<()> {
+    port.reconfigure(&|settings| {
+        settings.set_baud_rate(serial::Baud115200)?;
+        settings.set_char_size(serial::Bits8);
+        settings.set_parity(serial::ParityNone);
+        settings.set_stop_bits(serial::Stop1);
+        Ok(())
+    })?;
+
+    let mut written = 0;
+    loop {
+        let len = random::<usize>() % 0x1000;
+        let buf: Vec<u8> = (written..written + len).map(|x| x as u8).collect();
+
+        port.write_all(&buf)?;
+
+        if sleep {
+            let micros = (random::<usize>() % 1000) as u64;
+            println!("Sleeping {}us", micros);
+            port.flush().unwrap();
+            thread::sleep(Duration::from_micros(micros));
+        }
+
+        written += len;
+        println!("Written: {}", written);
+    }
+}