rp2040 local resource example for rtic v2

Author: mike-kfed

rtic_v2/rp2040_local_i2c_init/Cargo.toml

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+[package]
+name = "rp2040_local_i2c_init"
+categories = ["embedded", "no-std"]
+description = "Example task local initialized resources for Raspberry Pi Pico"
+license = "MIT OR Apache-2.0"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+cortex-m = "0.7"
+rtic = { git = "https://github.com/rtic-rs/rtic", features = ["thumbv6-backend"] }
+rtic-monotonics = { git = "https://github.com/rtic-rs/rtic", features = ["cortex-m-systick", "rp2040"] }
+embedded-hal = { version = "0.2.7", features = ["unproven"] }
+fugit = "0.3"
+rp-pico = "0.7.0"
+panic-probe = "0.3"
+
+[profile.dev]
+opt-level = 1
+codegen-units = 16
+debug = true
+lto = false
+
+[profile.release]
+opt-level = "s"   # optimize for size
+codegen-units = 1 # better optimizations
+debug = true      # symbols are nice and they don't increase the size on Flash
+lto = true        # better optimzations

rtic_v2/rp2040_local_i2c_init/Embed.toml

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+[default.probe]
+protocol = "Swd"
+speed = 20000
+# If you only have one probe cargo embed will pick automatically
+# Otherwise: add your probe's VID/PID/serial to filter
+
+## rust-dap
+# usb_vid = "6666"
+# usb_pid = "4444"
+# serial = "test"
+
+
+[default.flashing]
+enabled = true
+
+[default.reset]
+enabled = true
+halt_afterwards = false
+
+[default.general]
+chip = "RP2040"
+log_level = "WARN"
+# RP2040 does not support connect_under_reset
+connect_under_reset = false
+
+[default.rtt]
+enabled = true
+up_mode = "NoBlockSkip"
+channels = [
+    { up = 0, down = 0, name = "name", up_mode = "NoBlockSkip", format = "Defmt" },
+]
+timeout = 3000
+show_timestamps = true
+log_enabled = false
+log_path = "./logs"
+
+[default.gdb]
+enabled = true
+gdb_connection_string = "127.0.0.1:2345"

rtic_v2/rp2040_local_i2c_init/build.rs

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+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+}

rtic_v2/rp2040_local_i2c_init/memory.x

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+MEMORY {
+    BOOT2 : ORIGIN = 0x10000000, LENGTH = 0x100
+    FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
+    RAM   : ORIGIN = 0x20000000, LENGTH = 256K
+}
+
+EXTERN(BOOT2_FIRMWARE)
+
+SECTIONS {
+    /* ### Boot loader */
+    .boot2 ORIGIN(BOOT2) :
+    {
+        KEEP(*(.boot2));
+    } > BOOT2
+} INSERT BEFORE .text;

rtic_v2/rp2040_local_i2c_init/src/main.rs

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+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+#[rtic::app(
+    device = rp_pico::hal::pac,
+    dispatchers = [TIMER_IRQ_1]
+)]
+mod app {
+    use rp_pico::hal::{
+        clocks, gpio,
+        gpio::pin::bank0::{Gpio2, Gpio25, Gpio3},
+        gpio::pin::PushPullOutput,
+        pac,
+        sio::Sio,
+        watchdog::Watchdog,
+        I2C,
+    };
+    use rp_pico::XOSC_CRYSTAL_FREQ;
+
+    use core::mem::MaybeUninit;
+    use embedded_hal::digital::v2::{OutputPin, ToggleableOutputPin};
+    use fugit::RateExtU32;
+    use rtic_monotonics::systick::*;
+
+    use panic_probe as _;
+
+    rtic_monotonics::make_systick_handler!();
+
+    type I2CBus = I2C<
+        pac::I2C1,
+        (
+            gpio::Pin<Gpio2, gpio::FunctionI2C>,
+            gpio::Pin<Gpio3, gpio::FunctionI2C>,
+        ),
+    >;
+
+    #[shared]
+    struct Shared {}
+
+    #[local]
+    struct Local {
+        led: gpio::Pin<Gpio25, PushPullOutput>,
+        i2c: &'static mut I2CBus,
+    }
+
+    #[init(local=[
+        // Task local initialized resources are static
+        // Here we use MaybeUninit to allow for initialization in init()
+        // This enables its usage in driver initialization
+        i2c_ctx: MaybeUninit<I2CBus> = MaybeUninit::uninit()
+    ])]
+    fn init(mut ctx: init::Context) -> (Shared, Local) {
+        // Configure the clocks, watchdog - The default is to generate a 125 MHz system clock
+        Systick::start(ctx.core.SYST, 125_000_000); // default rp2040 clock-rate is 125MHz
+        let mut watchdog = Watchdog::new(ctx.device.WATCHDOG);
+        let clocks = clocks::init_clocks_and_plls(
+            XOSC_CRYSTAL_FREQ,
+            ctx.device.XOSC,
+            ctx.device.CLOCKS,
+            ctx.device.PLL_SYS,
+            ctx.device.PLL_USB,
+            &mut ctx.device.RESETS,
+            &mut watchdog,
+        )
+        .ok()
+        .unwrap();
+
+        // Init LED pin
+        let sio = Sio::new(ctx.device.SIO);
+        let gpioa = rp_pico::Pins::new(
+            ctx.device.IO_BANK0,
+            ctx.device.PADS_BANK0,
+            sio.gpio_bank0,
+            &mut ctx.device.RESETS,
+        );
+        let mut led = gpioa.led.into_push_pull_output();
+        led.set_low().unwrap();
+
+        // Init I2C pins
+        let sda_pin = gpioa.gpio2.into_mode::<gpio::FunctionI2C>();
+        let scl_pin = gpioa.gpio3.into_mode::<gpio::FunctionI2C>();
+
+        // Init I2C itself, using MaybeUninit to overwrite the previously
+        // uninitialized i2c_ctx variable without dropping its value
+        // (i2c_ctx definined in init local resources above)
+        let i2c_tmp: &'static mut _ = ctx.local.i2c_ctx.write(I2C::i2c1(
+            ctx.device.I2C1,
+            sda_pin,
+            scl_pin,
+            100.kHz(),
+            &mut ctx.device.RESETS,
+            &clocks.system_clock,
+        ));
+
+        // Spawn heartbeat task
+        heartbeat::spawn().ok();
+
+        // Return resources and timer
+        (Shared {}, Local { led, i2c: i2c_tmp })
+    }
+
+    #[task(local = [i2c, led])]
+    async fn heartbeat(ctx: heartbeat::Context) {
+        // Flicker the built-in LED
+        _ = ctx.local.led.toggle();
+
+        // Congrats, you can use your i2c and have access to it here,
+        // now to do something with it!
+
+        // Re-spawn this task after 1 second
+        Systick::delay(1000.millis()).await;
+    }
+}