diff --git a/Software/src/lib/miwagner-ESP32-Arduino-CAN/CAN.h b/Software/src/lib/miwagner-ESP32-Arduino-CAN/CAN.h
index d39fde88..d8e925b8 100644
--- a/Software/src/lib/miwagner-ESP32-Arduino-CAN/CAN.h
+++ b/Software/src/lib/miwagner-ESP32-Arduino-CAN/CAN.h
@@ -93,6 +93,10 @@ typedef struct {
 	uint8_t 			AMR3;				/**< \brief Acceptance Mask Register AMR3 */
 } CAN_filter_t;
 
+extern void gpio_matrix_in(uint32_t gpio, uint32_t signal_idx, bool inv);
+extern void gpio_matrix_out(uint32_t gpio, uint32_t signal_idx, bool out_inv, bool oen_inv);
+extern void gpio_pad_select_gpio(uint8_t gpio_num);
+
 /**
  * \brief Initialize the CAN Module
  *