diff --git a/.github/workflows/cmake-gcc-arm.yml b/.github/workflows/cmake-gcc-arm.yml
index 6e0e370..7609dbb 100644
--- a/.github/workflows/cmake-gcc-arm.yml
+++ b/.github/workflows/cmake-gcc-arm.yml
@@ -39,9 +39,8 @@ jobs:
       # Build your program with the given configuration
       run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}}
 
-    - name: Test
-      working-directory: ${{github.workspace}}/build
-      # Execute tests defined by the CMake configuration.
-      # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
-      run: ctest -C ${{env.BUILD_TYPE}}
-
+    - name: Upload final build artifacts
+      uses: actions/upload-artifact@v4
+      with:
+        name: stm32-i2c-hid
+        path: ${{github.workspace}}/build/stm32-i2c-hid.*
diff --git a/c2usb b/c2usb
index 1535029..3cdccdf 160000
--- a/c2usb
+++ b/c2usb
@@ -1 +1 @@
-Subproject commit 1535029b9e47f2119d057ed34e96b58974ec5543
+Subproject commit 3cdccdf05a44986be854fbb3ba5cac4baa98c6ca
diff --git a/cmake/gcc-arm-none-eabi.cmake b/cmake/gcc-arm-none-eabi.cmake
index bd572db..0976345 100644
--- a/cmake/gcc-arm-none-eabi.cmake
+++ b/cmake/gcc-arm-none-eabi.cmake
@@ -30,9 +30,10 @@ set(TARGET_FLAGS "-mcpu=cortex-m0 ")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${TARGET_FLAGS}")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fdata-sections -ffunction-sections ")
 
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra ")
 # skip warnings
 if(FALSE)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wpedantic ")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wpedantic ")
 endif()
 
 if(CMAKE_BUILD_TYPE MATCHES Debug)
diff --git a/stm32-i2c-hid/hid/demo_app.cpp b/stm32-i2c-hid/hid/demo_app.cpp
index e255887..9ebbd56 100644
--- a/stm32-i2c-hid/hid/demo_app.cpp
+++ b/stm32-i2c-hid/hid/demo_app.cpp
@@ -53,7 +53,7 @@ demo_app& demo_app::instance()
     return app;
 }
 
-void demo_app::start(protocol prot)
+void demo_app::start([[maybe_unused]] protocol prot)
 {
     receive_report(&_raw_out_buffer);
 }
@@ -70,7 +70,7 @@ void demo_app::button_state_change(bool pressed)
     }
 }
 
-void demo_app::set_report(report::type type, const std::span<const uint8_t>& data)
+void demo_app::set_report([[maybe_unused]] report::type type, const std::span<const uint8_t>& data)
 {
     // only output reports provided
     assert(type == report::type::OUTPUT);
@@ -91,7 +91,8 @@ void demo_app::set_report(report::type type, const std::span<const uint8_t>& dat
     receive_report(&_raw_out_buffer);
 }
 
-void demo_app::get_report(report::selector select, const std::span<uint8_t>& buffer)
+void demo_app::get_report(report::selector select,
+                          [[maybe_unused]] const std::span<uint8_t>& buffer)
 {
     if (select == _keys_buffer.selector())
     {
diff --git a/stm32-i2c-hid/i2c_hid_config.cpp b/stm32-i2c-hid/i2c_hid_config.cpp
index 8b3a4c2..45c729b 100644
--- a/stm32-i2c-hid/i2c_hid_config.cpp
+++ b/stm32-i2c-hid/i2c_hid_config.cpp
@@ -63,23 +63,23 @@ extern "C" void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
     }
 }
 
-extern "C" void HAL_I2C_AddrCallback(I2C_HandleTypeDef* hi2c, uint8_t TransferDirection,
-                                     uint16_t AddrMatchCode)
+extern "C" void HAL_I2C_AddrCallback([[maybe_unused]] I2C_HandleTypeDef* hi2c,
+                                     uint8_t TransferDirection, uint16_t AddrMatchCode)
 {
     get_i2c_slave().handle_start(static_cast<i2c::direction>(TransferDirection));
 }
 
-extern "C" void HAL_I2C_ListenCpltCallback(I2C_HandleTypeDef* hi2c)
+extern "C" void HAL_I2C_ListenCpltCallback([[maybe_unused]] I2C_HandleTypeDef* hi2c)
 {
     get_i2c_slave().handle_stop();
 }
 
-extern "C" void HAL_I2C_SlaveTxCpltCallback(I2C_HandleTypeDef* hi2c)
+extern "C" void HAL_I2C_SlaveTxCpltCallback([[maybe_unused]] I2C_HandleTypeDef* hi2c)
 {
     get_i2c_slave().handle_tx_complete();
 }
 
-extern "C" void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef* hi2c)
+extern "C" void HAL_I2C_SlaveRxCpltCallback([[maybe_unused]] I2C_HandleTypeDef* hi2c)
 {
     get_i2c_slave().handle_rx_complete();
 }
diff --git a/stm32-i2c-hid/newlib_diet.cpp b/stm32-i2c-hid/newlib_diet.cpp
index 0814f89..52760fc 100644
--- a/stm32-i2c-hid/newlib_diet.cpp
+++ b/stm32-i2c-hid/newlib_diet.cpp
@@ -15,6 +15,7 @@ extern "C" void _fini(void) {}
 extern "C" void __register_exitproc(void) {}
 
 void operator delete(void*, unsigned int) {}
+void operator delete(void*) {}
 
 /* needed to avoid pulling in a lot of library code */
 #ifndef NDEBUG
diff --git a/stm32-i2c-hid/st/hal_i2c_slave.cpp b/stm32-i2c-hid/st/hal_i2c_slave.cpp
index 0ee901a..f5ca158 100644
--- a/stm32-i2c-hid/st/hal_i2c_slave.cpp
+++ b/stm32-i2c-hid/st/hal_i2c_slave.cpp
@@ -61,7 +61,7 @@ void hal_i2c_slave::start_listen()
     HAL_I2C_EnableListen_IT(handle_);
 }
 
-void hal_i2c_slave::stop_listen(i2c::address slave_addr)
+void hal_i2c_slave::stop_listen([[maybe_unused]] i2c::address slave_addr)
 {
     HAL_I2C_DisableListen_IT(handle_);
 }