diff --git a/hepa-uv/simulator/CMakeLists.txt b/hepa-uv/simulator/CMakeLists.txt
index a8ce6d81b..b364d4425 100644
--- a/hepa-uv/simulator/CMakeLists.txt
+++ b/hepa-uv/simulator/CMakeLists.txt
@@ -28,6 +28,7 @@ add_library(freertos-hepa-uv STATIC ${FREERTOS_SOURCES})
 
 set(HEPA_UV_SIMULATOR_SRC
         ${CMAKE_CURRENT_SOURCE_DIR}/main.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/gpio.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/freertos_idle_timer_task.cpp
         )
 
diff --git a/hepa-uv/simulator/gpio.cpp b/hepa-uv/simulator/gpio.cpp
new file mode 100644
index 000000000..a1806439a
--- /dev/null
+++ b/hepa-uv/simulator/gpio.cpp
@@ -0,0 +1,16 @@
+#pragma once
+#include <cstdint>
+
+namespace gpio {
+
+struct PinConfig {
+    void* port;
+    uint16_t pin;
+    uint8_t active_setting;
+};
+
+auto set(const PinConfig& pc) -> void;
+auto reset(const PinConfig& pc) -> void;
+auto is_set(const PinConfig& pc) -> bool;
+
+};  // namespace gpio