added some doc comments

units/digital_out/unit_dout.h

@@ -9,14 +9,49 @@
 
 extern const UnitDriver UNIT_DOUT;
 
+/**
+ * Write pins (e.g. writing 0b10 if configured pins are PA5 and PA0 sets PA5=1,PA0=0)
+ *
+ * @param unit
+ * @param packed - packed pin states (aligned to right)
+ * @return success
+ */
 error_t UU_DO_Write(Unit *unit, uint16_t packed);
 
+/**
+ * Set pins (clear none)
+ *
+ * @param unit
+ * @param packed - packed pins, 1 if pin should be set
+ * @return success
+ */
 error_t UU_DO_Set(Unit *unit, uint16_t packed);
 
+/**
+ * Clear multiple pins
+ *
+ * @param unit
+ * @param packed - packed pins, 1 if pin should be cleared
+ * @return
+ */
 error_t UU_DO_Clear(Unit *unit, uint16_t packed);
 
+/**
+ * Toggle pins
+ *
+ * @param unit
+ * @param packed - packed pins, 1 if pin should be toggled
+ * @return
+ */
 error_t UU_DO_Toggle(Unit *unit, uint16_t packed);
 
+/**
+ * Get number of configured pins
+ *
+ * @param unit
+ * @param count output, written with 0-16
+ * @return success
+ */
 error_t UU_DO_GetPinCount(Unit *unit, uint8_t *count);
 
 #endif //U_DOUT_H