diff --git a/inc/system/gpio.h b/inc/system/gpio.h
--- a/inc/system/gpio.h
+++ b/inc/system/gpio.h
@@ -29,6 +29,7 @@
 #define LED_GPIO_Port GPIOB
 #define LED LED_GPIO_Port, LED_PIN
 
+/// SSR PIN ???///
 
 void user_input(uint16_t* to_modify);
 void user_input_signed(int32_t* to_modify);