Comments and refactoring

src/io.h

@@ -5,9 +5,23 @@
 #include <stm32f4xx.h>
 
 
+/**
+ *   @brief Initialize all used GPIOs and initialize their clock source.
+ */
 void io_init(void);
+
+/**
+ *   @brief Edge detection for the buttons which were initialized by io_init.
+ *          Gets called by the systick timer.
+ */
 void io_process(void);
+
+/**
+ *   @brief Edge handler which clears the edge bit to make sure a button press gets only handled once per tick.
+ *
+ *   @param btnnumber   Button number
+ *   @return            True if the button has a positive edge.
+ */
 bool io_button_has_edge(uint8_t btnnumber);
 
-
 #endif /* IO_H */