diff -r b74b0e4902c3 -r ad2c8b13eb88 main/task_driver.c
--- a/main/task_driver.c	Sat Oct 20 13:23:15 2018 +0200
+++ b/main/task_driver.c	Sat Oct 20 17:09:48 2018 +0200
@@ -15,22 +15,25 @@
 #include "config.h"
 
 
-#define	SSR_MLT		CONFIG_SSR_MLT_GPIO
-#define	SSR_HLT		CONFIG_SSR_HLT_GPIO
-#define SSR_PUMP	CONFIG_SSR_PUMP_GPIO
+#define	SSR_MLT		CONFIG_SSR_MLT_GPIO			///< GPIO SSR MLT pin
+#define	SSR_HLT		CONFIG_SSR_HLT_GPIO			///< GPIO SSR HLT pin
+#define SSR_PUMP	CONFIG_SSR_PUMP_GPIO			///< GPIO Pump relay pin
 
 
-bool			outEnable = false;
-DRIVER_State		* driver_state;
-SemaphoreHandle_t	xSemaphoreDriver  = NULL;
-int			MLT_pin = 0;
-int			HLT_pin = 0;
-int			Pump_pin = 0;
-double			Input = 0, Output = 0, Setpoint = 0;
-int			MLT_Mode = MLT_MODE_NONE;
-double			HLT_Input = 0, HLT_Setpoint = 0;
-int			HLT_Output = 0;
-int			HLT_Mode = HLT_MODE_NONE;
+bool			outEnable = false;			///< Enable outputs flag
+DRIVER_State		* driver_state;				///< Driver state
+SemaphoreHandle_t	xSemaphoreDriver  = NULL;		///< Driver state lock
+int			MLT_pin = 0;				///< MLT state
+int			HLT_pin = 0;				///< HLT state
+int			Pump_pin = 0;				///< Pump state
+double			Input = 0;				///< PID input value
+double			Output = 0;				///< PID output value
+double			Setpoint = 0;				///< PID setpoint value
+int			MLT_Mode = MLT_MODE_NONE;		///< MLT mode flag
+double			HLT_Input = 0;				///< HLT input value
+double			HLT_Setpoint = 0;			///< HLT setpoint values
+int			HLT_Output = 0;				///< HLT output value
+int			HLT_Mode = HLT_MODE_NONE;		///< HLT mode flag
 
 static const char       *TAG = "task_driver";
 
@@ -95,6 +98,9 @@
 
 
 
+/**
+ * @brief Load PID settings from equipment record.
+ */
 void LoadPIDsettings() {
     PID_SetTunings(equipment.PID_kP, equipment.PID_kI, equipment.PID_kD, equipment.PID_POn);
     PID_SetSampleTime(equipment.SampleTime);