Added first rp2040 code example

.gitignore

@@ -1,3 +1,5 @@
 firmware/compile_commands.json
 firmware/.cache/clangd/index
 firmware/.ccls-cache
+rp2040/target
+rp2040/Cargo.lock

rp2040/.cargo/config

@@ -0,0 +1,42 @@
+#
+# Cargo Configuration for the https://github.com/rp-rs/rp-hal.git repository.
+#
+# Copyright (c) The RP-RS Developers, 2021
+#
+# You might want to make a similar file in your own repository if you are
+# writing programs for Raspberry Silicon microcontrollers.
+#
+# This file is MIT or Apache-2.0 as per the repository README.md file
+#
+
+[build]
+# Set the default target to match the Cortex-M0+ in the RP2040
+target = "thumbv6m-none-eabi"
+
+# Target specific options
+[target.thumbv6m-none-eabi]
+# Pass some extra options to rustc, some of which get passed on to the linker.
+#
+# * linker argument --nmagic turns off page alignment of sections (which saves
+#   flash space)
+# * linker argument -Tlink.x tells the linker to use link.x as the linker
+#   script. This is usually provided by the cortex-m-rt crate, and by default
+#   the version in that crate will include a file called `memory.x` which
+#   describes the particular memory layout for your specific chip. 
+# * inline-threshold=5 makes the compiler more aggressive and inlining functions
+# * no-vectorize-loops turns off the loop vectorizer (seeing as the M0+ doesn't
+#   have SIMD)
+rustflags = [
+    "-C", "link-arg=--nmagic",
+    "-C", "link-arg=-Tlink.x",
+    "-C", "inline-threshold=5",
+    "-C", "no-vectorize-loops",
+]
+
+# This runner will make a UF2 file and then copy it to a mounted RP2040 in USB
+# Bootloader mode:
+runner = "elf2uf2-rs -d"
+
+# This runner will find a supported SWD debug probe and flash your RP2040 over
+# SWD:
+# runner = "probe-run --chip RP2040"

rp2040/Cargo.toml

@@ -0,0 +1,45 @@
+[package]
+name = "rp2040"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+cortex-m = "0.7.2"
+waveshare-rp2040-zero = "0.6.0"
+rp2040-boot2 = { version = "0.2.0", optional = true }
+rp2040-hal = { version = "0.8.0" }
+cortex-m-rt = { version = "0.7", optional = true }
+panic-halt= "0.2.0"
+embedded-hal ="0.2.5"
+fugit = "0.3.5"
+nb = "1.0.0"
+smart-leds = "0.3.0"
+ws2812-pio = "0.6.0"
+
+[features]
+# This is the set of features we enable by default
+default = ["boot2", "rt", "critical-section-impl", "rom-func-cache"]
+
+# critical section that is safe for multicore use
+critical-section-impl = ["rp2040-hal/critical-section-impl"]
+
+# 2nd stage bootloaders for rp2040
+boot2 = ["rp2040-boot2"]
+
+# Minimal startup / runtime for Cortex-M microcontrollers
+rt = ["cortex-m-rt","rp2040-hal/rt"]
+
+# This enables a fix for USB errata 5: USB device fails to exit RESET state on busy USB bus.
+# Only required for RP2040 B0 and RP2040 B1, but it doesn't hurt to enable it
+rp2040-e5 = ["rp2040-hal/rp2040-e5"]
+
+# Memoize(cache) ROM function pointers on first use to improve performance
+rom-func-cache = ["rp2040-hal/rom-func-cache"]
+
+# Disable automatic mapping of language features (like floating point math) to ROM functions
+disable-intrinsics = ["rp2040-hal/disable-intrinsics"]
+
+# This enables ROM functions for f64 math that were not present in the earliest RP2040s
+rom-v2-intrinsics = ["rp2040-hal/rom-v2-intrinsics"]

rp2040/memory.x

@@ -0,0 +1,15 @@
+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;

rp2040/pico-load

@@ -0,0 +1,12 @@
+#!/bin/bash
+sudo umount /mnt/usb
+while [ ! -f /mnt/usb/INFO_UF2.TXT ]; do
+    sudo mount /dev/sda1 /mnt/usb -o umask=000
+    sleep 1
+done
+set -e
+# cargo build --release --example waveshare_rp2040_zero_neopixel_rainbow
+cargo run --release 
+# elf2uf2-rs $1
+# cp $1.uf2 /mnt/usb
+sudo umount /mnt/usb

rp2040/src/main.rs

@@ -0,0 +1,76 @@
+//! Rainbow effect color wheel using the onboard NeoPixel on an Waveshare RP2040 Zero board
+//!
+//! This flows smoothly through various colors on the onboard NeoPixel.
+//! Uses the `ws2812_pio` driver to control the NeoPixel, which in turns uses the
+//! RP2040's PIO block.
+#![no_std]
+#![no_main]
+
+use embedded_hal::timer::CountDown;
+use fugit::ExtU32;
+use panic_halt as _;
+use smart_leds::{SmartLedsWrite, RGB8};
+use waveshare_rp2040_zero::entry;
+use waveshare_rp2040_zero::{
+    hal::{
+        clocks::{init_clocks_and_plls, Clock},
+        pac,
+        pio::PIOExt,
+        timer::Timer,
+        watchdog::Watchdog,
+        Sio,
+    },
+    Pins, XOSC_CRYSTAL_FREQ,
+};
+use ws2812_pio::Ws2812;
+
+#[entry]
+fn main() -> ! {
+    let mut pac = pac::Peripherals::take().unwrap();
+
+    let mut watchdog = Watchdog::new(pac.WATCHDOG);
+
+    let clocks = init_clocks_and_plls(
+        XOSC_CRYSTAL_FREQ,
+        pac.XOSC,
+        pac.CLOCKS,
+        pac.PLL_SYS,
+        pac.PLL_USB,
+        &mut pac.RESETS,
+        &mut watchdog,
+    )
+    .ok()
+    .unwrap();
+
+    let sio = Sio::new(pac.SIO);
+    let pins = Pins::new(
+        pac.IO_BANK0,
+        pac.PADS_BANK0,
+        sio.gpio_bank0,
+        &mut pac.RESETS,
+    );
+
+    let timer = Timer::new(pac.TIMER, &mut pac.RESETS);
+    let mut delay = timer.count_down();
+
+    // Configure the addressable LED
+    let (mut pio, sm0, _, _, _) = pac.PIO0.split(&mut pac.RESETS);
+    let mut ws = Ws2812::new(
+        // The onboard NeoPixel is attached to GPIO pin #16 on the Feather RP2040.
+        pins.neopixel.into_mode(),
+        &mut pio,
+        sm0,
+        clocks.peripheral_clock.freq(),
+        timer.count_down(),
+    );
+
+    // Infinite colour wheel loop
+    loop {
+        let color_green : RGB8 = (0, 10, 10).into();
+        ws.write([color_green].iter().copied()).unwrap();
+
+        delay.start(25.millis());
+        let _ = nb::block!(delay.wait());
+    }
+}
+