diff --git a/README.md b/README.md
index 479657c..ffa53fd 100644
--- a/README.md
+++ b/README.md
@@ -518,6 +518,7 @@ Rust ports of the C drivers above using `rp235x-hal`. Each Rust driver folder co
|--------|-------------|------------|
| [0x01_uart_rust](drivers/0x01_uart_rust) | Raw UART transmit / receive | `rp235x-hal`, `embedded-hal-nb` |
| [0x02_blink_rust](drivers/0x02_blink_rust) | GPIO output LED blink | `rp235x-hal`, `embedded-hal` |
+| [0x03_button_rust](drivers/0x03_button_rust) | Push-button input with debounce | `rp235x-hal`, `embedded-hal` |
diff --git a/drivers/0x03_button_rust/.cargo/config.toml b/drivers/0x03_button_rust/.cargo/config.toml
new file mode 100644
index 0000000..1791d74
--- /dev/null
+++ b/drivers/0x03_button_rust/.cargo/config.toml
@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: MIT OR Apache-2.0
+#
+# Copyright (c) 2021–2024 The rp-rs Developers
+# Copyright (c) 2021 rp-rs organization
+# Copyright (c) 2025 Raspberry Pi Ltd.
+#
+# Cargo Configuration for the https://github.com/rp-rs/rp-hal.git repository.
+#
+# You might want to make a similar file in your own repository if you are
+# writing programs for Raspberry Silicon microcontrollers.
+#
+
+[build]
+target = "thumbv8m.main-none-eabihf"
+# Set the default target to match the Cortex-M33 in the RP2350
+# target = "thumbv8m.main-none-eabihf"
+# target = "thumbv6m-none-eabi"
+# target = "riscv32imac-unknown-none-elf"
+
+# 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.
+# * no-vectorize-loops turns off the loop vectorizer (seeing as the M0+ doesn't
+# have SIMD)
+linker = "flip-link"
+rustflags = [
+ "-C", "link-arg=--nmagic",
+ "-C", "link-arg=-Tlink.x",
+ "-C", "link-arg=-Tdefmt.x",
+ "-C", "no-vectorize-loops",
+]
+
+# Use picotool for loading.
+#
+# Load an elf, skipping unchanged flash sectors, verify it, and execute it
+runner = "${PICOTOOL_PATH} load -u -v -x -t elf"
+#runner = "probe-rs run --chip ${CHIP} --protocol swd"
+
+# This is the hard-float ABI for Arm mode.
+#
+# The FPU is enabled by default, and float function arguments use FPU
+# registers.
+[target.thumbv8m.main-none-eabihf]
+# Pass some extra options to rustc, some of which get passed on to the linker.
+#
+# * linker argument --nmagic turns off page alignment of sections (which saves
+# flash space)
+# * linker argument -Tlink.x tells the linker to use link.x as a linker script.
+# This is usually provided by the cortex-m-rt crate, and by default the
+# version in that crate will include a file called `memory.x` which describes
+# the particular memory layout for your specific chip.
+# * linker argument -Tdefmt.x also tells the linker to use `defmt.x` as a
+# secondary linker script. This is required to make defmt_rtt work.
+rustflags = [
+ "-C", "link-arg=--nmagic",
+ "-C", "link-arg=-Tlink.x",
+ "-C", "link-arg=-Tdefmt.x",
+ "-C", "target-cpu=cortex-m33",
+]
+
+# Use picotool for loading.
+#
+# Load an elf, skipping unchanged flash sectors, verify it, and execute it
+runner = "${PICOTOOL_PATH} load -u -v -x -t elf"
+#runner = "probe-rs run --chip ${CHIP} --protocol swd"
+
+# This is the soft-float ABI for RISC-V mode.
+#
+# Hazard 3 does not have an FPU and so float function arguments use integer
+# registers.
+[target.riscv32imac-unknown-none-elf]
+# Pass some extra options to rustc, some of which get passed on to the linker.
+#
+# * linker argument --nmagic turns off page alignment of sections (which saves
+# flash space)
+# * linker argument -Trp235x_riscv.x also tells the linker to use
+# `rp235x_riscv.x` as a linker script. This adds in RP2350 RISC-V specific
+# things that the riscv-rt crate's `link.x` requires and then includes
+# `link.x` automatically. This is the reverse of how we do it on Cortex-M.
+# * linker argument -Tdefmt.x also tells the linker to use `defmt.x` as a
+# secondary linker script. This is required to make defmt_rtt work.
+rustflags = [
+ "-C", "link-arg=--nmagic",
+ "-C", "link-arg=-Trp2350_riscv.x",
+ "-C", "link-arg=-Tdefmt.x",
+]
+
+# Use picotool for loading.
+#
+# Load an elf, skipping unchanged flash sectors, verify it, and execute it
+runner = "${PICOTOOL_PATH} load -u -v -x -t elf"
+#runner = "probe-rs run --chip ${CHIP} --protocol swd"
+
+[env]
+DEFMT_LOG = "debug"
diff --git a/drivers/0x03_button_rust/.gitignore b/drivers/0x03_button_rust/.gitignore
new file mode 100644
index 0000000..03381c1
--- /dev/null
+++ b/drivers/0x03_button_rust/.gitignore
@@ -0,0 +1,113 @@
+# Created by https://www.toptal.com/developers/gitignore/api/rust,visualstudiocode,macos,windows,linux
+# Edit at https://www.toptal.com/developers/gitignore?templates=rust,visualstudiocode,macos,windows,linux
+
+### Linux ###
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### macOS ###
+# General
+.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two
+Icon
+
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### macOS Patch ###
+# iCloud generated files
+*.icloud
+
+### Rust ###
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+### VisualStudioCode ###
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+!.vscode/*.code-snippets
+
+# Local History for Visual Studio Code
+.history/
+
+# Built Visual Studio Code Extensions
+*.vsix
+
+### VisualStudioCode Patch ###
+# Ignore all local history of files
+.history
+.ionide
+
+### Windows ###
+# Windows thumbnail cache files
+Thumbs.db
+Thumbs.db:encryptable
+ehthumbs.db
+ehthumbs_vista.db
+
+# Dump file
+*.stackdump
+
+# Folder config file
+[Dd]esktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msix
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+# End of https://www.toptal.com/developers/gitignore/api/rust,visualstudiocode,macos,windows,linux
diff --git a/drivers/0x03_button_rust/.pico-rs b/drivers/0x03_button_rust/.pico-rs
new file mode 100644
index 0000000..1b6702a
--- /dev/null
+++ b/drivers/0x03_button_rust/.pico-rs
@@ -0,0 +1 @@
+rp2350
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/.vscode/extensions.json b/drivers/0x03_button_rust/.vscode/extensions.json
new file mode 100644
index 0000000..5f2fd0c
--- /dev/null
+++ b/drivers/0x03_button_rust/.vscode/extensions.json
@@ -0,0 +1,8 @@
+{
+ "recommendations": [
+ "marus25.cortex-debug",
+ "rust-lang.rust-analyzer",
+ "probe-rs.probe-rs-debugger",
+ "raspberry-pi.raspberry-pi-pico"
+ ]
+}
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/.vscode/launch.json b/drivers/0x03_button_rust/.vscode/launch.json
new file mode 100644
index 0000000..0bc38c3
--- /dev/null
+++ b/drivers/0x03_button_rust/.vscode/launch.json
@@ -0,0 +1,41 @@
+{
+ "version": "0.2.0",
+ "configurations": [
+ {
+ "name": "Pico Debug (probe-rs)",
+ "cwd": "${workspaceFolder}",
+ "request": "launch",
+ "type": "probe-rs-debug",
+ "connectUnderReset": false,
+ "speed": 5000,
+ "runtimeExecutable": "probe-rs",
+ "chip": "${command:raspberry-pi-pico.getChip}",
+ "runtimeArgs": [
+ "dap-server"
+ ],
+ "flashingConfig": {
+ "flashingEnabled": true,
+ "haltAfterReset": false
+ },
+ "coreConfigs": [
+ {
+ "coreIndex": 0,
+ "programBinary": "${command:raspberry-pi-pico.launchTargetPath}",
+ "rttEnabled": true,
+ "svdFile": "${command:raspberry-pi-pico.getSVDPath}",
+ "rttChannelFormats": [
+ {
+ "channelNumber": 0,
+ "dataFormat": "Defmt",
+ "mode": "NoBlockSkip",
+ "showTimestamps": true
+ }
+ ]
+ }
+ ],
+ "preLaunchTask": "Build + Generate SBOM (debug)",
+ "consoleLogLevel": "Debug",
+ "wireProtocol": "Swd"
+ }
+ ]
+}
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/.vscode/settings.json b/drivers/0x03_button_rust/.vscode/settings.json
new file mode 100644
index 0000000..b03cd57
--- /dev/null
+++ b/drivers/0x03_button_rust/.vscode/settings.json
@@ -0,0 +1,8 @@
+{
+ "rust-analyzer.cargo.target": "thumbv8m.main-none-eabihf",
+ "rust-analyzer.check.allTargets": false,
+ "editor.formatOnSave": true,
+ "files.exclude": {
+ ".pico-rs": true
+ }
+}
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/.vscode/tasks.json b/drivers/0x03_button_rust/.vscode/tasks.json
new file mode 100644
index 0000000..4194af4
--- /dev/null
+++ b/drivers/0x03_button_rust/.vscode/tasks.json
@@ -0,0 +1,124 @@
+{
+ "version": "2.0.0",
+ "tasks": [
+ {
+ "label": "Compile Project",
+ "type": "process",
+ "isBuildCommand": true,
+ "command": "cargo",
+ "args": [
+ "build",
+ "--release"
+ ],
+ "group": {
+ "kind": "build",
+ "isDefault": true
+ },
+ "presentation": {
+ "reveal": "always",
+ "panel": "dedicated"
+ },
+ "problemMatcher": "$rustc",
+ "options": {
+ "env": {
+ "PICOTOOL_PATH": "${command:raspberry-pi-pico.getPicotoolPath}",
+ "CHIP": "${command:raspberry-pi-pico.getChip}"
+ }
+ }
+ },
+ {
+ "label": "Build + Generate SBOM (release)",
+ "type": "shell",
+ "command": "bash",
+ "args": [
+ "-lc",
+ "cargo sbom > ${command:raspberry-pi-pico.sbomTargetPathRelease}"
+ ],
+ "windows": {
+ "command": "powershell",
+ "args": [
+ "-NoProfile",
+ "-ExecutionPolicy",
+ "Bypass",
+ "-Command",
+ "cargo sbom | Set-Content -Encoding utf8 ${command:raspberry-pi-pico.sbomTargetPathRelease}"
+ ]
+ },
+ "dependsOn": "Compile Project",
+ "presentation": {
+ "reveal": "silent",
+ "panel": "shared"
+ },
+ "problemMatcher": []
+ },
+ {
+ "label": "Compile Project (debug)",
+ "type": "process",
+ "isBuildCommand": true,
+ "command": "cargo",
+ "args": [
+ "build"
+ ],
+ "group": {
+ "kind": "build",
+ "isDefault": false
+ },
+ "presentation": {
+ "reveal": "always",
+ "panel": "dedicated"
+ },
+ "problemMatcher": "$rustc",
+ "options": {
+ "env": {
+ "PICOTOOL_PATH": "${command:raspberry-pi-pico.getPicotoolPath}",
+ "CHIP": "${command:raspberry-pi-pico.getChip}"
+ }
+ }
+ },
+ {
+ "label": "Build + Generate SBOM (debug)",
+ "type": "shell",
+ "command": "bash",
+ "args": [
+ "-lc",
+ "cargo sbom > ${command:raspberry-pi-pico.sbomTargetPathDebug}"
+ ],
+ "windows": {
+ "command": "powershell",
+ "args": [
+ "-NoProfile",
+ "-ExecutionPolicy",
+ "Bypass",
+ "-Command",
+ "cargo sbom | Set-Content -Encoding utf8 ${command:raspberry-pi-pico.sbomTargetPathDebug}"
+ ]
+ },
+ "dependsOn": "Compile Project (debug)",
+ "presentation": {
+ "reveal": "silent",
+ "panel": "shared"
+ },
+ "problemMatcher": []
+ },
+ {
+ "label": "Run Project",
+ "type": "shell",
+ "dependsOn": [
+ "Build + Generate SBOM (release)"
+ ],
+ "command": "${command:raspberry-pi-pico.getPicotoolPath}",
+ "args": [
+ "load",
+ "-x",
+ "${command:raspberry-pi-pico.launchTargetPathRelease}",
+ "-t",
+ "elf"
+ ],
+ "presentation": {
+ "reveal": "always",
+ "panel": "dedicated"
+ },
+ "problemMatcher": []
+ }
+ ]
+}
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/Cargo.toml b/drivers/0x03_button_rust/Cargo.toml
new file mode 100644
index 0000000..8784140
--- /dev/null
+++ b/drivers/0x03_button_rust/Cargo.toml
@@ -0,0 +1,41 @@
+
+[package]
+edition = "2024"
+name = "button"
+version = "0.1.0"
+license = "MIT or Apache-2.0"
+
+[lib]
+name = "button_lib"
+path = "src/lib.rs"
+
+[[bin]]
+name = "button"
+path = "src/main.rs"
+
+[build-dependencies]
+regex = "1.11.0"
+
+[dependencies]
+cortex-m = "0.7"
+cortex-m-rt = "0.7"
+embedded-hal = "1.0.0"
+fugit = "0.3"
+defmt = "1"
+defmt-rtt = "1"
+
+[target.'cfg( target_arch = "arm" )'.dependencies]
+panic-probe = { version = "1", features = ["print-defmt"] }
+
+[target.'cfg( target_arch = "riscv32" )'.dependencies]
+panic-halt = { version = "1.0.0" }
+
+[target.thumbv6m-none-eabi.dependencies]
+rp2040-boot2 = "0.3"
+rp2040-hal = { version = "0.11", features = ["rt", "critical-section-impl"] }
+
+[target.riscv32imac-unknown-none-elf.dependencies]
+rp235x-hal = { version = "0.3", features = ["rt", "critical-section-impl"] }
+
+[target."thumbv8m.main-none-eabihf".dependencies]
+rp235x-hal = { version = "0.3", features = ["rt", "critical-section-impl"] }
diff --git a/drivers/0x03_button_rust/LICENSE-APACHE b/drivers/0x03_button_rust/LICENSE-APACHE
new file mode 100644
index 0000000..8d99cbc
--- /dev/null
+++ b/drivers/0x03_button_rust/LICENSE-APACHE
@@ -0,0 +1,204 @@
+
+ Apache License
+ Version 2.0, January 2004
+ http://www.apache.org/licenses/
+
+ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+ 1. Definitions.
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+ identification within third-party archives.
+
+ Copyright (c) 2021–2024 The rp-rs Developers
+ Copyright (c) 2021 rp-rs organization
+ Copyright (c) 2025 Raspberry Pi Ltd.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/LICENSE-MIT b/drivers/0x03_button_rust/LICENSE-MIT
new file mode 100644
index 0000000..5369c70
--- /dev/null
+++ b/drivers/0x03_button_rust/LICENSE-MIT
@@ -0,0 +1,24 @@
+MIT License
+
+Copyright (c) 2021–2024 The rp-rs Developers
+Copyright (c) 2021 rp-rs organization
+Copyright (c) 2025 Raspberry Pi Ltd.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/build.rs b/drivers/0x03_button_rust/build.rs
new file mode 100644
index 0000000..e6de3f1
--- /dev/null
+++ b/drivers/0x03_button_rust/build.rs
@@ -0,0 +1,68 @@
+//! SPDX-License-Identifier: MIT OR Apache-2.0
+//!
+//! Copyright (c) 2021–2024 The rp-rs Developers
+//! Copyright (c) 2021 rp-rs organization
+//! Copyright (c) 2025 Raspberry Pi Ltd.
+//!
+//! Set up linker scripts
+
+use std::fs::{ File, read_to_string };
+use std::io::Write;
+use std::path::PathBuf;
+
+use regex::Regex;
+
+fn main() {
+ println!("cargo::rustc-check-cfg=cfg(rp2040)");
+ println!("cargo::rustc-check-cfg=cfg(rp2350)");
+
+ // Put the linker script somewhere the linker can find it
+ let out = PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
+ println!("cargo:rustc-link-search={}", out.display());
+
+ println!("cargo:rerun-if-changed=.pico-rs");
+ let contents = read_to_string(".pico-rs")
+ .map(|s| s.trim().to_string().to_lowercase())
+ .unwrap_or_else(|e| {
+ eprintln!("Failed to read file: {}", e);
+ String::new()
+ });
+
+ // The file `memory.x` is loaded by cortex-m-rt's `link.x` script, which
+ // is what we specify in `.cargo/config.toml` for Arm builds
+ let target;
+ if contents == "rp2040" {
+ target = "thumbv6m-none-eabi";
+ let memory_x = include_bytes!("rp2040.x");
+ let mut f = File::create(out.join("memory.x")).unwrap();
+ f.write_all(memory_x).unwrap();
+ println!("cargo::rustc-cfg=rp2040");
+ println!("cargo:rerun-if-changed=rp2040.x");
+ } else {
+ if contents.contains("riscv") {
+ target = "riscv32imac-unknown-none-elf";
+ } else {
+ target = "thumbv8m.main-none-eabihf";
+ }
+ let memory_x = include_bytes!("rp2350.x");
+ let mut f = File::create(out.join("memory.x")).unwrap();
+ f.write_all(memory_x).unwrap();
+ println!("cargo::rustc-cfg=rp2350");
+ println!("cargo:rerun-if-changed=rp2350.x");
+ }
+
+ let re = Regex::new(r"target = .*").unwrap();
+ let config_toml = include_str!(".cargo/config.toml");
+ let result = re.replace(config_toml, format!("target = \"{}\"", target));
+ let mut f = File::create(".cargo/config.toml").unwrap();
+ f.write_all(result.as_bytes()).unwrap();
+
+ // The file `rp2350_riscv.x` is what we specify in `.cargo/config.toml` for
+ // RISC-V builds
+ let rp2350_riscv_x = include_bytes!("rp2350_riscv.x");
+ let mut f = File::create(out.join("rp2350_riscv.x")).unwrap();
+ f.write_all(rp2350_riscv_x).unwrap();
+ println!("cargo:rerun-if-changed=rp2350_riscv.x");
+
+ println!("cargo:rerun-if-changed=build.rs");
+}
diff --git a/drivers/0x03_button_rust/rp2040.x b/drivers/0x03_button_rust/rp2040.x
new file mode 100644
index 0000000..0cc665b
--- /dev/null
+++ b/drivers/0x03_button_rust/rp2040.x
@@ -0,0 +1,91 @@
+/*
+* SPDX-License-Identifier: MIT OR Apache-2.0
+*
+* Copyright (c) 2021–2024 The rp-rs Developers
+* Copyright (c) 2021 rp-rs organization
+* Copyright (c) 2025 Raspberry Pi Ltd.
+*/
+
+MEMORY {
+ BOOT2 : ORIGIN = 0x10000000, LENGTH = 0x100
+ /*
+ * Here we assume you have 2048 KiB of Flash. This is what the Pi Pico
+ * has, but your board may have more or less Flash and you should adjust
+ * this value to suit.
+ */
+ FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
+ /*
+ * RAM consists of 4 banks, SRAM0-SRAM3, with a striped mapping.
+ * This is usually good for performance, as it distributes load on
+ * those banks evenly.
+ */
+ RAM : ORIGIN = 0x20000000, LENGTH = 256K
+ /*
+ * RAM banks 4 and 5 use a direct mapping. They can be used to have
+ * memory areas dedicated for some specific job, improving predictability
+ * of access times.
+ * Example: Separate stacks for core0 and core1.
+ */
+ SRAM4 : ORIGIN = 0x20040000, LENGTH = 4k
+ SRAM5 : ORIGIN = 0x20041000, LENGTH = 4k
+
+ /* SRAM banks 0-3 can also be accessed directly. However, those ranges
+ alias with the RAM mapping, above. So don't use them at the same time!
+ SRAM0 : ORIGIN = 0x21000000, LENGTH = 64k
+ SRAM1 : ORIGIN = 0x21010000, LENGTH = 64k
+ SRAM2 : ORIGIN = 0x21020000, LENGTH = 64k
+ SRAM3 : ORIGIN = 0x21030000, LENGTH = 64k
+ */
+}
+
+EXTERN(BOOT2_FIRMWARE)
+
+SECTIONS {
+ /* ### Boot loader
+ *
+ * An executable block of code which sets up the QSPI interface for
+ * 'Execute-In-Place' (or XIP) mode. Also sends chip-specific commands to
+ * the external flash chip.
+ *
+ * Must go at the start of external flash, where the Boot ROM expects it.
+ */
+ .boot2 ORIGIN(BOOT2) :
+ {
+ KEEP(*(.boot2));
+ } > BOOT2
+} INSERT BEFORE .text;
+
+SECTIONS {
+ /* ### Boot ROM info
+ *
+ * Goes after .vector_table, to keep it in the first 512 bytes of flash,
+ * where picotool can find it
+ */
+ .boot_info : ALIGN(4)
+ {
+ KEEP(*(.boot_info));
+ } > FLASH
+
+} INSERT AFTER .vector_table;
+
+/* move .text to start /after/ the boot info */
+_stext = ADDR(.boot_info) + SIZEOF(.boot_info);
+
+SECTIONS {
+ /* ### Picotool 'Binary Info' Entries
+ *
+ * Picotool looks through this block (as we have pointers to it in our
+ * header) to find interesting information.
+ */
+ .bi_entries : ALIGN(4)
+ {
+ /* We put this in the header */
+ __bi_entries_start = .;
+ /* Here are the entries */
+ KEEP(*(.bi_entries));
+ /* Keep this block a nice round size */
+ . = ALIGN(4);
+ /* We put this in the header */
+ __bi_entries_end = .;
+ } > FLASH
+} INSERT AFTER .text;
diff --git a/drivers/0x03_button_rust/rp2350.x b/drivers/0x03_button_rust/rp2350.x
new file mode 100644
index 0000000..bda94d8
--- /dev/null
+++ b/drivers/0x03_button_rust/rp2350.x
@@ -0,0 +1,83 @@
+/*
+* SPDX-License-Identifier: MIT OR Apache-2.0
+*
+* Copyright (c) 2021–2024 The rp-rs Developers
+* Copyright (c) 2021 rp-rs organization
+* Copyright (c) 2025 Raspberry Pi Ltd.
+*/
+
+MEMORY {
+ /*
+ * The RP2350 has either external or internal flash.
+ *
+ * 2 MiB is a safe default here, although a Pico 2 has 4 MiB.
+ */
+ FLASH : ORIGIN = 0x10000000, LENGTH = 2048K
+ /*
+ * RAM consists of 8 banks, SRAM0-SRAM7, with a striped mapping.
+ * This is usually good for performance, as it distributes load on
+ * those banks evenly.
+ */
+ RAM : ORIGIN = 0x20000000, LENGTH = 512K
+ /*
+ * RAM banks 8 and 9 use a direct mapping. They can be used to have
+ * memory areas dedicated for some specific job, improving predictability
+ * of access times.
+ * Example: Separate stacks for core0 and core1.
+ */
+ SRAM4 : ORIGIN = 0x20080000, LENGTH = 4K
+ SRAM5 : ORIGIN = 0x20081000, LENGTH = 4K
+ }
+
+ SECTIONS {
+ /* ### Boot ROM info
+ *
+ * Goes after .vector_table, to keep it in the first 4K of flash
+ * where the Boot ROM (and picotool) can find it
+ */
+ .start_block : ALIGN(4)
+ {
+ __start_block_addr = .;
+ KEEP(*(.start_block));
+ } > FLASH
+
+ } INSERT AFTER .vector_table;
+
+ /* move .text to start /after/ the boot info */
+ _stext = ADDR(.start_block) + SIZEOF(.start_block);
+
+ SECTIONS {
+ /* ### Picotool 'Binary Info' Entries
+ *
+ * Picotool looks through this block (as we have pointers to it in our
+ * header) to find interesting information.
+ */
+ .bi_entries : ALIGN(4)
+ {
+ /* We put this in the header */
+ __bi_entries_start = .;
+ /* Here are the entries */
+ KEEP(*(.bi_entries));
+ /* Keep this block a nice round size */
+ . = ALIGN(4);
+ /* We put this in the header */
+ __bi_entries_end = .;
+ } > FLASH
+ } INSERT AFTER .text;
+
+ SECTIONS {
+ /* ### Boot ROM extra info
+ *
+ * Goes after everything in our program, so it can contain a signature.
+ */
+ .end_block : ALIGN(4)
+ {
+ __end_block_addr = .;
+ KEEP(*(.end_block));
+ } > FLASH
+
+ } INSERT AFTER .uninit;
+
+ PROVIDE(start_to_end = __end_block_addr - __start_block_addr);
+ PROVIDE(end_to_start = __start_block_addr - __end_block_addr);
+
\ No newline at end of file
diff --git a/drivers/0x03_button_rust/rp2350_riscv.x b/drivers/0x03_button_rust/rp2350_riscv.x
new file mode 100644
index 0000000..84388aa
--- /dev/null
+++ b/drivers/0x03_button_rust/rp2350_riscv.x
@@ -0,0 +1,259 @@
+/*
+* SPDX-License-Identifier: MIT OR Apache-2.0
+*
+* Copyright (c) 2021–2024 The rp-rs Developers
+* Copyright (c) 2021 rp-rs organization
+* Copyright (c) 2025 Raspberry Pi Ltd.
+*/
+
+MEMORY {
+ /*
+ * The RP2350 has either external or internal flash.
+ *
+ * 2 MiB is a safe default here, although a Pico 2 has 4 MiB.
+ */
+ FLASH : ORIGIN = 0x10000000, LENGTH = 2048K
+ /*
+ * RAM consists of 8 banks, SRAM0-SRAM7, with a striped mapping.
+ * This is usually good for performance, as it distributes load on
+ * those banks evenly.
+ */
+ RAM : ORIGIN = 0x20000000, LENGTH = 512K
+ /*
+ * RAM banks 8 and 9 use a direct mapping. They can be used to have
+ * memory areas dedicated for some specific job, improving predictability
+ * of access times.
+ * Example: Separate stacks for core0 and core1.
+ */
+ SRAM4 : ORIGIN = 0x20080000, LENGTH = 4K
+ SRAM5 : ORIGIN = 0x20081000, LENGTH = 4K
+}
+
+/* # Developer notes
+
+- Symbols that start with a double underscore (__) are considered "private"
+
+- Symbols that start with a single underscore (_) are considered "semi-public"; they can be
+ overridden in a user linker script, but should not be referred from user code (e.g. `extern "C" {
+ static mut _heap_size }`).
+
+- `EXTERN` forces the linker to keep a symbol in the final binary. We use this to make sure a
+ symbol is not dropped if it appears in or near the front of the linker arguments and "it's not
+ needed" by any of the preceding objects (linker arguments)
+
+- `PROVIDE` is used to provide default values that can be overridden by a user linker script
+
+- On alignment: it's important for correctness that the VMA boundaries of both .bss and .data *and*
+ the LMA of .data are all `32`-byte aligned. These alignments are assumed by the RAM
+ initialization routine. There's also a second benefit: `32`-byte aligned boundaries
+ means that you won't see "Address (..) is out of bounds" in the disassembly produced by `objdump`.
+*/
+
+PROVIDE(_stext = ORIGIN(FLASH));
+PROVIDE(_stack_start = ORIGIN(RAM) + LENGTH(RAM));
+PROVIDE(_max_hart_id = 0);
+PROVIDE(_hart_stack_size = 2K);
+PROVIDE(_heap_size = 0);
+
+PROVIDE(InstructionMisaligned = ExceptionHandler);
+PROVIDE(InstructionFault = ExceptionHandler);
+PROVIDE(IllegalInstruction = ExceptionHandler);
+PROVIDE(Breakpoint = ExceptionHandler);
+PROVIDE(LoadMisaligned = ExceptionHandler);
+PROVIDE(LoadFault = ExceptionHandler);
+PROVIDE(StoreMisaligned = ExceptionHandler);
+PROVIDE(StoreFault = ExceptionHandler);
+PROVIDE(UserEnvCall = ExceptionHandler);
+PROVIDE(SupervisorEnvCall = ExceptionHandler);
+PROVIDE(MachineEnvCall = ExceptionHandler);
+PROVIDE(InstructionPageFault = ExceptionHandler);
+PROVIDE(LoadPageFault = ExceptionHandler);
+PROVIDE(StorePageFault = ExceptionHandler);
+
+PROVIDE(SupervisorSoft = DefaultHandler);
+PROVIDE(MachineSoft = DefaultHandler);
+PROVIDE(SupervisorTimer = DefaultHandler);
+PROVIDE(MachineTimer = DefaultHandler);
+PROVIDE(SupervisorExternal = DefaultHandler);
+PROVIDE(MachineExternal = DefaultHandler);
+
+PROVIDE(DefaultHandler = DefaultInterruptHandler);
+PROVIDE(ExceptionHandler = DefaultExceptionHandler);
+
+/* # Pre-initialization function */
+/* If the user overrides this using the `#[pre_init]` attribute or by creating a `__pre_init` function,
+ then the function this points to will be called before the RAM is initialized. */
+PROVIDE(__pre_init = default_pre_init);
+
+/* A PAC/HAL defined routine that should initialize custom interrupt controller if needed. */
+PROVIDE(_setup_interrupts = default_setup_interrupts);
+
+/* # Multi-processing hook function
+ fn _mp_hook() -> bool;
+
+ This function is called from all the harts and must return true only for one hart,
+ which will perform memory initialization. For other harts it must return false
+ and implement wake-up in platform-dependent way (e.g. after waiting for a user interrupt).
+*/
+PROVIDE(_mp_hook = default_mp_hook);
+
+/* # Start trap function override
+ By default uses the riscv crates default trap handler
+ but by providing the `_start_trap` symbol external crates can override.
+*/
+PROVIDE(_start_trap = default_start_trap);
+
+SECTIONS
+{
+ .text.dummy (NOLOAD) :
+ {
+ /* This section is intended to make _stext address work */
+ . = ABSOLUTE(_stext);
+ } > FLASH
+
+ .text _stext :
+ {
+ /* Put reset handler first in .text section so it ends up as the entry */
+ /* point of the program. */
+ KEEP(*(.init));
+ KEEP(*(.init.rust));
+ . = ALIGN(4);
+ __start_block_addr = .;
+ KEEP(*(.start_block));
+ . = ALIGN(4);
+ *(.trap);
+ *(.trap.rust);
+ *(.text.abort);
+ *(.text .text.*);
+ . = ALIGN(4);
+ } > FLASH
+
+ /* ### Picotool 'Binary Info' Entries
+ *
+ * Picotool looks through this block (as we have pointers to it in our
+ * header) to find interesting information.
+ */
+ .bi_entries : ALIGN(4)
+ {
+ /* We put this in the header */
+ __bi_entries_start = .;
+ /* Here are the entries */
+ KEEP(*(.bi_entries));
+ /* Keep this block a nice round size */
+ . = ALIGN(4);
+ /* We put this in the header */
+ __bi_entries_end = .;
+ } > FLASH
+
+ .rodata : ALIGN(4)
+ {
+ *(.srodata .srodata.*);
+ *(.rodata .rodata.*);
+
+ /* 4-byte align the end (VMA) of this section.
+ This is required by LLD to ensure the LMA of the following .data
+ section will have the correct alignment. */
+ . = ALIGN(4);
+ } > FLASH
+
+ .data : ALIGN(32)
+ {
+ _sidata = LOADADDR(.data);
+ __sidata = LOADADDR(.data);
+ _sdata = .;
+ __sdata = .;
+ /* Must be called __global_pointer$ for linker relaxations to work. */
+ PROVIDE(__global_pointer$ = . + 0x800);
+ *(.sdata .sdata.* .sdata2 .sdata2.*);
+ *(.data .data.*);
+ . = ALIGN(32);
+ _edata = .;
+ __edata = .;
+ } > RAM AT > FLASH
+
+ .bss (NOLOAD) : ALIGN(32)
+ {
+ _sbss = .;
+ *(.sbss .sbss.* .bss .bss.*);
+ . = ALIGN(32);
+ _ebss = .;
+ } > RAM
+
+ .end_block : ALIGN(4)
+ {
+ __end_block_addr = .;
+ KEEP(*(.end_block));
+ } > FLASH
+
+ /* fictitious region that represents the memory available for the heap */
+ .heap (NOLOAD) :
+ {
+ _sheap = .;
+ . += _heap_size;
+ . = ALIGN(4);
+ _eheap = .;
+ } > RAM
+
+ /* fictitious region that represents the memory available for the stack */
+ .stack (NOLOAD) :
+ {
+ _estack = .;
+ . = ABSOLUTE(_stack_start);
+ _sstack = .;
+ } > RAM
+
+ /* fake output .got section */
+ /* Dynamic relocations are unsupported. This section is only used to detect
+ relocatable code in the input files and raise an error if relocatable code
+ is found */
+ .got (INFO) :
+ {
+ KEEP(*(.got .got.*));
+ }
+
+ .eh_frame (INFO) : { KEEP(*(.eh_frame)) }
+ .eh_frame_hdr (INFO) : { *(.eh_frame_hdr) }
+}
+
+PROVIDE(start_to_end = __end_block_addr - __start_block_addr);
+PROVIDE(end_to_start = __start_block_addr - __end_block_addr);
+
+
+/* Do not exceed this mark in the error messages above | */
+ASSERT(ORIGIN(FLASH) % 4 == 0, "
+ERROR(riscv-rt): the start of the FLASH must be 4-byte aligned");
+
+ASSERT(ORIGIN(RAM) % 32 == 0, "
+ERROR(riscv-rt): the start of the RAM must be 32-byte aligned");
+
+ASSERT(_stext % 4 == 0, "
+ERROR(riscv-rt): `_stext` must be 4-byte aligned");
+
+ASSERT(_sdata % 32 == 0 && _edata % 32 == 0, "
+BUG(riscv-rt): .data is not 32-byte aligned");
+
+ASSERT(_sidata % 32 == 0, "
+BUG(riscv-rt): the LMA of .data is not 32-byte aligned");
+
+ASSERT(_sbss % 32 == 0 && _ebss % 32 == 0, "
+BUG(riscv-rt): .bss is not 32-byte aligned");
+
+ASSERT(_sheap % 4 == 0, "
+BUG(riscv-rt): start of .heap is not 4-byte aligned");
+
+ASSERT(_stext + SIZEOF(.text) < ORIGIN(FLASH) + LENGTH(FLASH), "
+ERROR(riscv-rt): The .text section must be placed inside the FLASH region.
+Set _stext to an address smaller than 'ORIGIN(FLASH) + LENGTH(FLASH)'");
+
+ASSERT(SIZEOF(.stack) > (_max_hart_id + 1) * _hart_stack_size, "
+ERROR(riscv-rt): .stack section is too small for allocating stacks for all the harts.
+Consider changing `_max_hart_id` or `_hart_stack_size`.");
+
+ASSERT(SIZEOF(.got) == 0, "
+.got section detected in the input files. Dynamic relocations are not
+supported. If you are linking to C code compiled using the `gcc` crate
+then modify your build script to compile the C code _without_ the
+-fPIC flag. See the documentation of the `gcc::Config.fpic` method for
+details.");
+
+/* Do not exceed this mark in the error messages above | */
diff --git a/drivers/0x03_button_rust/src/button.rs b/drivers/0x03_button_rust/src/button.rs
new file mode 100644
index 0000000..c98376e
--- /dev/null
+++ b/drivers/0x03_button_rust/src/button.rs
@@ -0,0 +1,254 @@
+//! @file button.rs
+//! @brief Implementation of the push-button GPIO input driver with debounce
+//! @author Kevin Thomas
+//! @date 2025
+//!
+//! MIT License
+//!
+//! Copyright (c) 2025 Kevin Thomas
+//!
+//! Permission is hereby granted, free of charge, to any person obtaining a copy
+//! of this software and associated documentation files (the "Software"), to deal
+//! in the Software without restriction, including without limitation the rights
+//! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//! copies of the Software, and to permit persons to whom the Software is
+//! furnished to do so, subject to the following conditions:
+//!
+//! The above copyright notice and this permission notice shall be included in
+//! all copies or substantial portions of the Software.
+//!
+//! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//! SOFTWARE.
+
+use embedded_hal::digital::{InputPin, OutputPin, StatefulOutputPin};
+
+/// Push-button GPIO input driver with debounce.
+pub struct ButtonDriver {
+ btn_pin: B,
+ debounce_ms: u32,
+ delay_fn: D,
+}
+
+impl ButtonDriver {
+ /// Initialize a GPIO pin as an active-low button input with pull-up.
+ ///
+ /// The pin reads logic high when the button is open and logic low when
+ /// the button connects the pin to GND.
+ ///
+ /// # Arguments
+ ///
+ /// * `btn_pin` - GPIO pin configured as input with pull-up.
+ /// * `debounce_ms` - Debounce settling time in milliseconds (e.g. 20).
+ /// * `delay_fn` - Closure that sleeps for the given number of milliseconds.
+ ///
+ /// # Returns
+ ///
+ /// A new ButtonDriver instance.
+ pub fn init(btn_pin: B, debounce_ms: u32, delay_fn: D) -> Self {
+ Self { btn_pin, debounce_ms, delay_fn }
+ }
+
+ /// Confirm a raw active-low pin read by waiting for the debounce period.
+ ///
+ /// After an initial low reading on the pin, this helper re-samples the pin
+ /// after debounce_ms milliseconds to confirm the reading is stable.
+ ///
+ /// # Returns
+ ///
+ /// `true` if the pin is still low after the debounce delay.
+ fn debounce_confirm(&mut self) -> bool {
+ (self.delay_fn)(self.debounce_ms);
+ self.btn_pin.is_low().unwrap()
+ }
+
+ /// Read the debounced state of the button.
+ ///
+ /// Returns true only when the pin reads low continuously for the debounce
+ /// period configured in init(). This prevents mechanical contact bounce
+ /// from registering as multiple rapid presses.
+ ///
+ /// # Returns
+ ///
+ /// `true` if the button is firmly pressed, `false` if released.
+ pub fn is_pressed(&mut self) -> bool {
+ if self.btn_pin.is_low().unwrap() {
+ return self.debounce_confirm();
+ }
+ false
+ }
+}
+
+/// Indicator LED driver that owns a single output pin.
+pub struct ButtonLed {
+ led_pin: L,
+}
+
+impl ButtonLed {
+ /// Initialize a GPIO pin as a push-pull digital output for an indicator LED.
+ ///
+ /// Configures the output and drives it low (LED off).
+ ///
+ /// # Arguments
+ ///
+ /// * `led_pin` - GPIO pin configured as a digital output.
+ ///
+ /// # Returns
+ ///
+ /// A new ButtonLed instance.
+ pub fn init(mut led_pin: L) -> Self {
+ led_pin.set_low().unwrap();
+ Self { led_pin }
+ }
+
+ /// Set the indicator LED state.
+ ///
+ /// Drives the output pin high (LED on) or low (LED off).
+ ///
+ /// # Arguments
+ ///
+ /// * `on` - `true` to turn the LED on, `false` to turn it off.
+ pub fn set(&mut self, on: bool) {
+ if on {
+ self.led_pin.set_high().unwrap();
+ } else {
+ self.led_pin.set_low().unwrap();
+ }
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ use core::convert::Infallible;
+ use embedded_hal::digital::ErrorType;
+
+ struct MockInputPin {
+ low: bool,
+ }
+
+ impl MockInputPin {
+ fn new(low: bool) -> Self {
+ Self { low }
+ }
+ }
+
+ impl ErrorType for MockInputPin {
+ type Error = Infallible;
+ }
+
+ impl InputPin for MockInputPin {
+ fn is_high(&mut self) -> Result {
+ Ok(!self.low)
+ }
+ fn is_low(&mut self) -> Result {
+ Ok(self.low)
+ }
+ }
+
+ struct MockOutputPin {
+ state: bool,
+ }
+
+ impl MockOutputPin {
+ fn new() -> Self {
+ Self { state: false }
+ }
+ }
+
+ impl ErrorType for MockOutputPin {
+ type Error = Infallible;
+ }
+
+ impl OutputPin for MockOutputPin {
+ fn set_low(&mut self) -> Result<(), Self::Error> {
+ self.state = false;
+ Ok(())
+ }
+ fn set_high(&mut self) -> Result<(), Self::Error> {
+ self.state = true;
+ Ok(())
+ }
+ }
+
+ impl StatefulOutputPin for MockOutputPin {
+ fn is_set_high(&mut self) -> Result {
+ Ok(self.state)
+ }
+ fn is_set_low(&mut self) -> Result {
+ Ok(!self.state)
+ }
+ fn toggle(&mut self) -> Result<(), Self::Error> {
+ self.state = !self.state;
+ Ok(())
+ }
+ }
+
+ fn noop_delay(_ms: u32) {}
+
+ #[test]
+ fn is_pressed_when_low_and_confirmed() {
+ let pin = MockInputPin::new(true);
+ let mut drv = ButtonDriver::init(pin, 20, noop_delay);
+ assert!(drv.is_pressed());
+ }
+
+ #[test]
+ fn is_not_pressed_when_high() {
+ let pin = MockInputPin::new(false);
+ let mut drv = ButtonDriver::init(pin, 20, noop_delay);
+ assert!(!drv.is_pressed());
+ }
+
+ #[test]
+ fn debounce_ms_stored() {
+ let pin = MockInputPin::new(false);
+ let drv = ButtonDriver::init(pin, 50, noop_delay);
+ assert_eq!(drv.debounce_ms, 50);
+ }
+
+ #[test]
+ fn debounce_calls_delay() {
+ let mut called_with: u32 = 0;
+ let pin = MockInputPin::new(true);
+ let mut drv = ButtonDriver::init(pin, 25, |ms| called_with = ms);
+ drv.is_pressed();
+ assert_eq!(called_with, 25);
+ }
+
+ #[test]
+ fn led_init_starts_off() {
+ let led = ButtonLed::init(MockOutputPin::new());
+ assert!(!led.led_pin.state);
+ }
+
+ #[test]
+ fn led_set_on() {
+ let mut led = ButtonLed::init(MockOutputPin::new());
+ led.set(true);
+ assert!(led.led_pin.state);
+ }
+
+ #[test]
+ fn led_set_off() {
+ let mut led = ButtonLed::init(MockOutputPin::new());
+ led.set(true);
+ led.set(false);
+ assert!(!led.led_pin.state);
+ }
+
+ #[test]
+ fn led_set_on_then_off_then_on() {
+ let mut led = ButtonLed::init(MockOutputPin::new());
+ led.set(true);
+ led.set(false);
+ led.set(true);
+ assert!(led.led_pin.state);
+ }
+}
+
+// End of file
diff --git a/drivers/0x03_button_rust/src/lib.rs b/drivers/0x03_button_rust/src/lib.rs
new file mode 100644
index 0000000..45b5692
--- /dev/null
+++ b/drivers/0x03_button_rust/src/lib.rs
@@ -0,0 +1,8 @@
+//! @file lib.rs
+//! @brief Library root for the button driver crate
+//! @author Kevin Thomas
+//! @date 2025
+
+#![no_std]
+
+pub mod button;
diff --git a/drivers/0x03_button_rust/src/main.rs b/drivers/0x03_button_rust/src/main.rs
new file mode 100644
index 0000000..1ef974a
--- /dev/null
+++ b/drivers/0x03_button_rust/src/main.rs
@@ -0,0 +1,247 @@
+//! @file main.rs
+//! @brief Button demonstration: debounced press mirrors to LED + UART report
+//! @author Kevin Thomas
+//! @date 2025
+//!
+//! MIT License
+//!
+//! Copyright (c) 2025 Kevin Thomas
+//!
+//! Permission is hereby granted, free of charge, to any person obtaining a copy
+//! of this software and associated documentation files (the "Software"), to deal
+//! in the Software without restriction, including without limitation the rights
+//! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//! copies of the Software, and to permit persons to whom the Software is
+//! furnished to do so, subject to the following conditions:
+//!
+//! The above copyright notice and this permission notice shall be included in
+//! all copies or substantial portions of the Software.
+//!
+//! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//! SOFTWARE.
+//!
+//! -----------------------------------------------------------------------------
+//!
+//! Demonstrates GPIO input using the button driver (button.rs).
+//! The onboard LED mirrors the button state and every edge transition is
+//! reported over UART.
+//!
+//! Wiring:
+//! GPIO15 -> One leg of push button
+//! GND -> Other leg of push button
+//! GPIO25 -> Onboard LED (no external wiring needed)
+
+#![no_std]
+#![no_main]
+
+#[allow(dead_code)]
+mod button;
+
+use defmt_rtt as _;
+#[cfg(target_arch = "riscv32")]
+use panic_halt as _;
+#[cfg(target_arch = "arm")]
+use panic_probe as _;
+
+use core::cell::RefCell;
+use fugit::RateExtU32;
+use hal::entry;
+use hal::Clock;
+use hal::gpio::{FunctionNull, FunctionUart, Pin, PullDown, PullNone};
+use hal::uart::{DataBits, Enabled, StopBits, UartConfig, UartPeripheral};
+
+#[cfg(rp2350)]
+use rp235x_hal as hal;
+
+#[cfg(rp2040)]
+use rp2040_hal as hal;
+
+#[unsafe(link_section = ".boot2")]
+#[used]
+#[cfg(rp2040)]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_W25Q080;
+
+#[unsafe(link_section = ".start_block")]
+#[used]
+#[cfg(rp2350)]
+pub static IMAGE_DEF: hal::block::ImageDef = hal::block::ImageDef::secure_exe();
+
+const XTAL_FREQ_HZ: u32 = 12_000_000u32;
+
+const UART_BAUD: u32 = 115_200;
+
+const DEBOUNCE_MS: u32 = 20;
+const POLL_MS: u32 = 10;
+
+type TxPin = Pin;
+type RxPin = Pin;
+type TxPinDefault = Pin;
+type RxPinDefault = Pin;
+type EnabledUart = UartPeripheral;
+
+/// Initialise system clocks and PLLs from the external 12 MHz crystal.
+///
+/// # Arguments
+///
+/// * `xosc` - XOSC peripheral singleton.
+/// * `clocks` - CLOCKS peripheral singleton.
+/// * `pll_sys` - PLL_SYS peripheral singleton.
+/// * `pll_usb` - PLL_USB peripheral singleton.
+/// * `resets` - Mutable reference to the RESETS peripheral.
+/// * `watchdog` - Mutable reference to the watchdog timer.
+///
+/// # Returns
+///
+/// Configured clocks manager.
+///
+/// # Panics
+///
+/// Panics if clock initialisation fails.
+fn init_clocks(
+ xosc: hal::pac::XOSC,
+ clocks: hal::pac::CLOCKS,
+ pll_sys: hal::pac::PLL_SYS,
+ pll_usb: hal::pac::PLL_USB,
+ resets: &mut hal::pac::RESETS,
+ watchdog: &mut hal::Watchdog,
+) -> hal::clocks::ClocksManager {
+ hal::clocks::init_clocks_and_plls(
+ XTAL_FREQ_HZ, xosc, clocks, pll_sys, pll_usb, resets, watchdog,
+ )
+ .unwrap()
+}
+
+/// Unlock the GPIO bank and return the pin set.
+///
+/// # Arguments
+///
+/// * `io_bank0` - IO_BANK0 peripheral singleton.
+/// * `pads_bank0` - PADS_BANK0 peripheral singleton.
+/// * `sio` - SIO peripheral singleton.
+/// * `resets` - Mutable reference to the RESETS peripheral.
+///
+/// # Returns
+///
+/// GPIO pin set for the entire bank.
+fn init_pins(
+ io_bank0: hal::pac::IO_BANK0,
+ pads_bank0: hal::pac::PADS_BANK0,
+ sio: hal::pac::SIO,
+ resets: &mut hal::pac::RESETS,
+) -> hal::gpio::Pins {
+ let sio = hal::Sio::new(sio);
+ hal::gpio::Pins::new(io_bank0, pads_bank0, sio.gpio_bank0, resets)
+}
+
+/// Initialise UART0 for serial output (stdio equivalent).
+///
+/// Configures UART0 at the requested baud rate with 8N1 framing on
+/// GPIO 0 (TX) and GPIO 1 (RX).
+///
+/// # Arguments
+///
+/// * `uart0` - PAC UART0 peripheral singleton.
+/// * `tx_pin` - GPIO pin to use as UART0 TX (GPIO 0).
+/// * `rx_pin` - GPIO pin to use as UART0 RX (GPIO 1).
+/// * `resets` - Mutable reference to the RESETS peripheral.
+/// * `clocks` - Reference to the initialised clock configuration.
+///
+/// # Returns
+///
+/// Enabled UART0 peripheral ready for blocking writes.
+///
+/// # Panics
+///
+/// Panics if the HAL cannot achieve the requested baud rate.
+fn init_uart(
+ uart0: hal::pac::UART0,
+ tx_pin: TxPinDefault,
+ rx_pin: RxPinDefault,
+ resets: &mut hal::pac::RESETS,
+ clocks: &hal::clocks::ClocksManager,
+) -> EnabledUart {
+ let pins = (
+ tx_pin.reconfigure::(),
+ rx_pin.reconfigure::(),
+ );
+ let cfg = UartConfig::new(UART_BAUD.Hz(), DataBits::Eight, None, StopBits::One);
+ UartPeripheral::new(uart0, pins, resets)
+ .enable(cfg, clocks.peripheral_clock.freq())
+ .unwrap()
+}
+
+/// Create a blocking delay timer from the ARM SysTick peripheral.
+///
+/// # Arguments
+///
+/// * `clocks` - Reference to the initialised clock configuration.
+///
+/// # Returns
+///
+/// Blocking delay provider.
+///
+/// # Panics
+///
+/// Panics if the cortex-m core peripherals have already been taken.
+fn init_delay(clocks: &hal::clocks::ClocksManager) -> cortex_m::delay::Delay {
+ let core = cortex_m::Peripherals::take().unwrap();
+ cortex_m::delay::Delay::new(core.SYST, clocks.system_clock.freq().to_Hz())
+}
+
+/// Application entry point for the button debounce demo.
+///
+/// Initializes button and LED, then continuously polls button state
+/// and mirrors it to the LED with UART reporting on edge transitions.
+///
+/// # Returns
+///
+/// Does not return.
+#[entry]
+fn main() -> ! {
+ let mut pac = hal::pac::Peripherals::take().unwrap();
+ let clocks = init_clocks(
+ pac.XOSC, pac.CLOCKS, pac.PLL_SYS, pac.PLL_USB, &mut pac.RESETS,
+ &mut hal::Watchdog::new(pac.WATCHDOG),
+ );
+ let pins = init_pins(pac.IO_BANK0, pac.PADS_BANK0, pac.SIO, &mut pac.RESETS);
+ let uart = init_uart(pac.UART0, pins.gpio0, pins.gpio1, &mut pac.RESETS, &clocks);
+ let delay = RefCell::new(init_delay(&clocks));
+ let btn_pin = pins.gpio15.into_pull_up_input();
+ let led_pin = pins.gpio25.into_push_pull_output();
+ let mut btn = button::ButtonDriver::init(btn_pin, DEBOUNCE_MS, |ms| {
+ delay.borrow_mut().delay_ms(ms);
+ });
+ let mut led = button::ButtonLed::init(led_pin);
+ uart.write_full_blocking(b"Button driver initialized: button=GPIO15 led=GPIO25\r\n");
+ let mut last_state = false;
+ loop {
+ let pressed = btn.is_pressed();
+ led.set(pressed);
+ if pressed != last_state {
+ if pressed {
+ uart.write_full_blocking(b"Button: PRESSED\r\n");
+ } else {
+ uart.write_full_blocking(b"Button: RELEASED\r\n");
+ }
+ last_state = pressed;
+ }
+ delay.borrow_mut().delay_ms(POLL_MS);
+ }
+}
+
+#[unsafe(link_section = ".bi_entries")]
+#[used]
+pub static PICOTOOL_ENTRIES: [hal::binary_info::EntryAddr; 5] = [
+ hal::binary_info::rp_cargo_bin_name!(),
+ hal::binary_info::rp_cargo_version!(),
+ hal::binary_info::rp_program_description!(c"Button Debounce Demo"),
+ hal::binary_info::rp_cargo_homepage_url!(),
+ hal::binary_info::rp_program_build_attribute!(),
+];
+
+// End of file