Add downloading of Wi-Fi/BT chipset firmware

.gitignore

@@ -1,5 +1,8 @@
 # Cargo
 target/
 
+# Firmware blobs
+cyw43-firmware/
+
 # VSCode
 .vscode

Cargo.toml

@@ -25,11 +25,18 @@ embassy-time = "0.4.0"
 embassy-embedded-hal = "0.3.0"
 embassy-futures = "0.1.1"
 embassy-sync = "0.6.2"
+trouble-host = { version = "0.1.0", default-features = false, features = [
+    "peripheral",
+    "gatt",
+    "derive",
+] }
 
 # System
 cortex-m-rt = "0.7.5"
 cortex-m = "0.7.7"
 critical-section = "1.2.0"
+cyw43 = { version = "0.3.0", features = ["bluetooth"] }
+cyw43-pio = "0.4.0"
 rtt-target = "0.6.1"
 
 # embedded-graphics
@@ -47,6 +54,13 @@ heapless = "0.8.0"
 circular-buffer = { version = "1.0.0", default-features = false }
 fixed = "1.29.0"
 
+[build-dependencies]
+reqwest = { version = "0.12.20", features = ["blocking"] }
+
+[features]
+# Skips downloading the Wi-Fi & Bluetooth chipset firmware, assumes that it is in `./cyw43-firmware`
+skip-cyw43-firmware = []
+
 [profile.dev]
 opt-level = "s"
 

build.rs

@@ -6,6 +6,9 @@ fn main() {
     let out = PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
     println!("cargo:rustc-link-search={}", out.display());
 
+    #[cfg(not(feature = "skip-cyw43-firmware"))]
+    download_cyw43_firmware();
+
     // ARM build
 
     let memory_x = include_bytes!("memory.x");
@@ -22,3 +25,41 @@ fn main() {
 
     println!("cargo:rerun-if-changed=build.rs");
 }
+
+/// Downloads to firmware for the Wi-Fi / Bluetooth chipset on the RPi Pico 2 W
+#[cfg(not(feature = "skip-cyw43-firmware"))]
+fn download_cyw43_firmware() {
+    let download_folder = "cyw43-firmware";
+    let url_base = "https://raw.githubusercontent.com/embassy-rs/embassy/refs/tags/cyw43-v0.3.0/cyw43-firmware";
+    let file_names = [
+        "43439A0.bin",
+        "43439A0_btfw.bin",
+        "43439A0_clm.bin",
+        "LICENSE-permissive-binary-license-1.0.txt",
+        "README.md",
+    ];
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed={}", download_folder);
+    std::fs::create_dir_all(download_folder).expect("failed to create firmware directory");
+
+    // download each file into the directory "cyw43-firmware"
+    for file in file_names {
+        let url = format!("{}/{}", url_base, file);
+        // only fetch if it doesn't exist
+        if std::path::Path::new(download_folder).join(file).exists() {
+            continue;
+        }
+        match reqwest::blocking::get(&url) {
+            Ok(response) => {
+                let content = response.bytes().expect("failed to read file content");
+                let file_path = PathBuf::from(download_folder).join(file);
+                std::fs::write(file_path, &content).expect("failed to write file");
+            }
+            Err(err) => panic!(
+                "failed to download the cyw43 firmware from {}: {}, required for BLE support",
+                url, err
+            ),
+        }
+    }
+}