Files
stm32_rust/usart_async_buffered_generalized2/src/uart/driver.rs
2025-10-31 13:19:54 +01:00

66 lines
1.9 KiB
Rust

// src/uart/driver.rs
use defmt::unwrap;
use embassy_executor::Spawner;
use embassy_futures::select::{select, Either};
use embassy_stm32::usart::BufferedUart;
use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
use embassy_sync::pipe::Pipe;
use embassy_time::Duration;
use embedded_io_async::{Read, Write};
use crate::uart::safety::{RX_PIPE_CAP, TX_PIPE_CAP};
pub struct UartHandle {
pub tx: &'static Pipe<CriticalSectionRawMutex, TX_PIPE_CAP>,
pub rx: &'static Pipe<CriticalSectionRawMutex, RX_PIPE_CAP>,
pub yield_period: Duration,
}
#[embassy_executor::task]
pub async fn uart_task(
mut uart: BufferedUart<'static>,
tx_pipe: &'static Pipe<CriticalSectionRawMutex, TX_PIPE_CAP>,
rx_pipe: &'static Pipe<CriticalSectionRawMutex, RX_PIPE_CAP>,
) {
let mut rx_byte = [0u8; 1];
let mut tx_buf = [0u8; 64];
loop {
let rx_fut = uart.read(&mut rx_byte);
let tx_fut = async {
let n = tx_pipe.read(&mut tx_buf).await;
n
};
match select(rx_fut, tx_fut).await {
// Incoming data from UART hardware
Either::First(res) => {
if let Ok(_) = res {
// Forward to RX pipe and echo to TX pipe (same behavior as before)
let _ = rx_pipe.write(&rx_byte).await;
let _ = tx_pipe.try_write(&rx_byte);
}
}
// Outgoing data waiting in TX pipe
Either::Second(n) => {
unwrap!(uart.write(&tx_buf[..n]).await);
}
}
}
}
pub fn spawn_for(
spawner: &Spawner,
uart: BufferedUart<'static>,
tx_pipe: &'static Pipe<CriticalSectionRawMutex, TX_PIPE_CAP>,
rx_pipe: &'static Pipe<CriticalSectionRawMutex, RX_PIPE_CAP>,
yield_period: Duration,
) -> UartHandle {
spawner.spawn(uart_task(uart, tx_pipe, rx_pipe)).unwrap();
UartHandle {
tx: tx_pipe,
rx: rx_pipe,
yield_period,
}
}