Add example code

It's just blinky

CMakeLists.txt

@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.20)
+
+include(pico_sdk_import.cmake)
+
+project(PicoNix C CXX ASM)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 23)
+
+pico_sdk_init()
+
+add_executable(main
+    src/main.cpp
+)
+
+target_link_libraries(main
+    pico_stdlib
+    pico_cyw43_arch_none
+)
+
+pico_add_extra_outputs(main)

flake.nix

@@ -31,6 +31,11 @@
                 inputsFrom = [ pico-sdk ];
                 packages = with pkgs;
                   [
+                    gcc-arm-embedded
+                    python3
+
+                    usbutils
+                    picotool
                   ]
                   ++ [ pico-sdk ];
 

src/main.cpp

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) 2022 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include "pico/cyw43_arch.h"
+#include "pico/stdlib.h"
+
+int main() {
+  stdio_init_all();
+  if (cyw43_arch_init()) {
+    printf("Wi-Fi init failed");
+    return -1;
+  }
+  while (true) {
+    cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
+    sleep_ms(500);
+    cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 0);
+    sleep_ms(500);
+  }
+}