updated UART echo RTIC example

examples/rtic/src/bin/uart-echo-rtic.rs

@@ -1,12 +1,7 @@
 //! More complex UART application
 //!
 //! Uses the IRQ capabilities of the VA10820 peripheral and the RTIC framework to poll the UART in
-//! a non-blocking way. You can send variably sized strings to the VA10820 which will be echoed
-//! back to the sender.
-//!
-//! This script was tested with an Arduino Due. You can find the test script in the
-//! [`/test/DueSerialTest`](https://egit.irs.uni-stuttgart.de/rust/va108xx-hal/src/branch/main/test/DueSerialTest)
-//! folder.
+//! a non-blocking way. All received data will be sent back to the sender.
 #![no_main]
 #![no_std]
 
@@ -26,37 +21,29 @@ mod app {
     use embedded_io::Write;
     use panic_rtt_target as _;
     use ringbuf::{
-        traits::{Observer, Producer},
+        traits::{Consumer, Observer, Producer, SplitRef},
         CachingCons, StaticProd,
     };
     use rtic_example::SYSCLK_FREQ;
-    use rtic_sync::make_channel;
+    use rtic_monotonics::Monotonic;
     use rtt_target::{rprintln, rtt_init_print};
     use va108xx_hal::{
         gpio::PinsB,
         pac,
         prelude::*,
-        uart::{self, IrqCfg, IrqContextTimeoutOrMaxSize, IrqResult, RxWithIrq},
+        uart::{self, RxWithIrq, Tx},
     };
 
     #[local]
     struct Local {
         data_producer: StaticProd<'static, u8, RX_RING_BUF_SIZE>,
         data_consumer: CachingCons<&'static StaticRb<u8, RX_RING_BUF_SIZE>>,
-        uart_rx: RxWithIrq<pac::Uartb>,
+        rx: RxWithIrq<pac::Uartb>,
+        tx: Tx<pac::Uartb>,
     }
 
     #[shared]
-    struct Shared {
-        rx_buf: [u8; 64],
-    }
-
-    #[derive(Debug, Copy, Clone)]
-    struct RxInfo {
-        pub bytes_read: usize,
-        pub end_idx: usize,
-        pub timeout: bool,
-    }
+    struct Shared {}
 
     rtic_monotonics::systick_monotonic!(Mono, 1_000);
 
@@ -72,23 +59,21 @@ mod app {
         let tx = gpiob.pb21.into_funsel_1();
         let rx = gpiob.pb20.into_funsel_1();
 
-        let irq_cfg = IrqCfg::new(pac::interrupt::OC3, true, true);
         let irq_uart =
             uart::Uart::new(&mut dp.sysconfig, 50.MHz(), dp.uartb, (tx, rx), 115200.Hz());
         let (tx, rx) = irq_uart.split();
-        let rx = rx.into_rx_with_irq(&dp.irqsel, pac::interrupt::OC3);
+        let mut rx = rx.into_rx_with_irq(&dp.irqsel, pac::interrupt::OC3);
 
-        let context = IrqContextTimeoutOrMaxSize::new(64);
-        rx.read_fixed_len_or_timeout_based_using_irq(&mut context)
-            .expect("UART RX init failed");
+        rx.start();
 
-        let (rx_info_tx, rx_info_rx) = make_channel!(RxInfo, 3);
-        let rx_buf: [u8; 64] = [0; 64];
+        let (data_producer, data_consumer) = unsafe { RINGBUF.split_ref() };
         (
-            Shared { uart_rx, rx_buf },
+            Shared {},
             Local {
-                rx_info_tx,
-                rx_info_rx,
+                data_producer,
+                data_consumer,
+                rx,
+                tx,
             },
         )
     }
@@ -103,16 +88,16 @@ mod app {
 
     #[task(
         binds = OC3,
-        shared = [rx_buf],
+        shared = [],
         local = [
-            uart_rx,
+            rx,
             data_producer
         ],
     )]
     fn reception_task(cx: reception_task::Context) {
         let mut buf: [u8; 16] = [0; 16];
         let mut ringbuf_full = false;
-        let result = cx.local.uart_rx.irq_handler(&mut buf);
+        let result = cx.local.rx.irq_handler(&mut buf);
         if result.bytes_read > 0 && result.errors.is_none() {
             if cx.local.data_producer.vacant_len() < result.bytes_read {
                 ringbuf_full = true;
@@ -128,32 +113,23 @@ mod app {
         }
     }
 
-    #[task(shared = [rx_buf], local = [data_consumer], priority=1)]
+    #[task(shared = [], local = [
+        buf: [u8; RX_RING_BUF_SIZE] = [0; RX_RING_BUF_SIZE],
+        data_consumer,
+        tx
+    ], priority=1)]
     async fn echo_handler(cx: echo_handler::Context) {
-        /*
-        let mut irq_uart = cx.shared.irq_uart;
-        let mut rx_buf = cx.shared.rx_buf;
         loop {
-            match cx.local.rx_info_rx.recv().await {
-                Ok(rx_info) => {
-                    rprintln!("reception success, {} bytes read", rx_info.bytes_read);
-                    if rx_info.timeout {
-                        rprintln!("timeout occurred");
-                    }
-                    rx_buf.lock(|rx_buf| {
-                        let string = core::str::from_utf8(&rx_buf[0..rx_info.end_idx])
-                            .expect("Invalid string format");
-                        rprintln!("read string: {}", string);
-                        irq_uart.lock(|uart| {
-                            writeln!(uart.uart, "{}", string).expect("Sending reply failed");
-                        });
-                    });
-                }
-                Err(e) => {
-                    rprintln!("error receiving RX info: {:?}", e);
-                }
-            }
+            let bytes_to_read = cx.local.data_consumer.occupied_len();
+            let actual_read_bytes = cx
+                .local
+                .data_consumer
+                .pop_slice(&mut cx.local.buf[0..bytes_to_read]);
+            cx.local
+                .tx
+                .write_all(&cx.local.buf[0..actual_read_bytes])
+                .expect("Failed to write to TX");
+            Mono::delay(50.millis()).await;
         }
-        */
     }
 }

vscode/launch.json

@@ -222,6 +222,30 @@
                 ]
             }
         },
+        {
+            "type": "cortex-debug",
+            "request": "launch",
+            "name": "UART Echo with RTIC",
+            "servertype": "jlink",
+            "cwd": "${workspaceRoot}",
+            "device": "Cortex-M0",
+            "svdFile": "./va108xx/svd/va108xx-base.svd.patched",
+            "preLaunchTask": "uart-echo-rtic-example",
+            "executable": "${workspaceFolder}/target/thumbv6m-none-eabi/debug/uart-echo-rtic",
+            "interface": "jtag",
+            "runToEntryPoint": "main",
+            "rttConfig": {
+                "enabled": true,
+                "address": "auto",
+                "decoders": [
+                    {
+                        "port": 0,
+                        "timestamp": true,
+                        "type": "console"
+                    }
+                ]
+            }
+        },
         {
             "type": "cortex-debug",
             "request": "launch",
@@ -428,4 +452,4 @@
             }
         },
     ]
-}
+}

vscode/tasks.json

@@ -122,13 +122,13 @@
             }
         },
         {
-            "label": "rust: cargo build uart irq",
+            "label": "uart-echo-rtic-example",
             "type": "shell",
             "command": "~/.cargo/bin/cargo", // note: full path to the cargo
             "args": [
                 "build",
                 "--bin",
-                "uart-rtic",
+                "uart-echo-rtic",
             ],
             "group": {
                 "kind": "build",