serial.rs

examples/serial.rs

+//! Serial echo
+//!
+//! Connect using e.g., `moserial` to `/dev/ttyACM0` (ACM number may change)
+//! 115200 8N1
+//!
+//! The MCU will echo incoming data and send a trace over ITM.
+//! Notice, as the hardware has a single byte buffer only, the input
+//! buffer may overflow.
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use panic_halt as _;
+
+use cortex_m_rt::entry;
+use nb::block;
+extern crate stm32f4xx_hal as hal;
+
+use crate::hal::prelude::*;
+use crate::hal::serial::{config::Config, Serial};
+use cortex_m::iprintln;
+
+#[entry]
+fn main() -> ! {
+    let mut c = hal::stm32::CorePeripherals::take().unwrap();
+    let stim = &mut c.ITM.stim[0];
+
+    let p = hal::stm32::Peripherals::take().unwrap();
+
+    let rcc = p.RCC.constrain();
+
+    let gpioa = p.GPIOA.split();
+
+    let clocks = rcc.cfgr.freeze();
+
+    let tx = gpioa.pa2.into_alternate_af7();
+    let rx = gpioa.pa3.into_alternate_af7(); // try comment out
+                                             // let rx = gpioa.pa3.into_alternate_af0(); // try uncomment
+
+    let serial = Serial::usart2(
+        p.USART2,
+        (tx, rx),
+        Config::default().baudrate(115_200.bps()),
+        clocks,
+    )
+    .unwrap();
+
+    // Separate out the sender and receiver of the serial port
+    let (mut tx, mut rx) = serial.split();
+
+    loop {
+        match block!(rx.read()) {
+            Ok(byte) => {
+                iprintln!(stim, "Ok {:?}", byte);
+                let _ = tx.write(byte);
+            }
+            Err(err) => {
+                iprintln!(stim, "Error {:?}", err);
+            }
+        }
+    }
+}