update README

README.md

@@ -1,83 +1,41 @@
-# smart-oil-heating-control-system
+# Smart Oil Heating Control System
 
-## Software
+ESP32-based control system for oil-fired central heating with schedule-based temperature management, safety monitoring, and Prometheus metrics export.
-### Design
 
+## Features
+
+- **Schedule Control**: Day/night temperature targets per weekday
+- **Summer Mode**: Automatic heating disable based on outdoor temperature
+- **Safety Monitoring**: Sensor sanity checks with automatic safe-state fallback
+- **Prometheus Metrics**: HTTP endpoint at port 9100
+
+## System Overview
 ```mermaid
-classDiagram
+flowchart TB
-Inputs <|-- Control
+    subgraph OUTSIDE[" "]
-Outputs <|-- Control
+        OT[/"🌡️ Outdoor Temp<br/>DS18B20"/]
-Sntp <|-- Control
+    end
-Inputs <|-- Safety
-Outputs <|--|> Safety
 
-Inputs <|-- Metrics
+    subgraph BURNER["OIL BURNER"]
-Outputs <|-- Metrics
+        CT[/"🌡️ Chamber Temp<br/>DS18B20"/]
-Control <|-- Metrics
+        BF[["⚠️ Burner Fault<br/>GPIO19 INPUT"]]
-Safety <|-- Metrics
+        BR(["🔥 Burner Relay<br/>GPIO14"])
-Sntp <|-- Metrics
+        SC(["🔌 Safety Contact<br/>GPIO12"])
+    end
 
-    class Inputs{
+    subgraph CIRCUIT["HEATING CIRCUIT"]
-        +initInputs()
+        IT[/"🌡️ Inlet Temp<br/>DS18B20"/]
-        -initMeasurement()
+        CP(["💧 Circulation Pump<br/>GPIO27"])
-        -updateAverage()
+        RT[/"🌡️ Return Temp<br/>DS18B20"/]
-        -updatePrediction()
+    end
-        -taskInput()
-        -linearRegressionPredict()
-        +getChamberTemperature()
-        +getOutdoorTemperature()
-        +getInletFlowTemperature()
-        +getReturnFlowTemperature()
-        +getBurnerError()
-    }
 
-    class Outputs{
+    RAD["🏠 Radiators"]
-        +initOutputs()
-        +getCirculationPumpState()
-        +setCirculationPumpState()
-        +getBurnerState()
-        +setBurnerState()
-        +getSafetyControlState()
-        +setSafetyControlState()
-    }
 
-    class Control{
+    BURNER -->|"hot water"| IT
-        initControl()
+    IT --> CP
-        +taskControl()
+    CP --> RAD
-        +getControlCurrentWeekday()
+    RAD --> RT
-        -findControlCurrentTemperatureEntry()
+    RT -->|"cold water"| BURNER
-        +getControlCurrentTemperatureEntry()
-        -controlTable
-        +getControlState()
-    }
-
-    class Safety{
-        +initSafety()
-        -taskSafety()
-        -setSafeState()
-        -checkSensorSanity()
-        +getSensorSanityStates()
-        +getSafetyState()
-    }
-
-
-    class Wifi{
-        +initWifi()
-    }
-
-    class Sntp{
-        +initSntp()
-        +getSntpState()
-    }
-
-    class Metrics{
-        +initMetrics()
-        -taskMetrics()
-        -metrics
-        +event_handler()
-        +connect_wifi()
-        +setMetrics()
-    }
 ```
 
 ### Prometheus Metrics
@@ -88,26 +46,26 @@ burner_fault_pending 1
 circulation_pump_enabled 1
 burner_enabled 0
 safety_contact_enabled 1
-chamber_temperature 37.250000
+chamber_temperature 37.312500
-chamber_temperature_avg10 37.237499
+chamber_temperature_avg10 37.393749
-chamber_temperature_avg60 37.438541
+chamber_temperature_avg60 37.689583
-chamber_temperature_damped 42.185040
+chamber_temperature_damped 38.058098
-chamber_temperature_pred60 36.638443
+chamber_temperature_pred60 36.697266
-inlet_flow_temperature 35.625000
+inlet_flow_temperature 34.562500
-inlet_flow_temperature_avg10 35.618752
+inlet_flow_temperature_avg10 34.587502
-inlet_flow_temperature_avg60 35.415627
+inlet_flow_temperature_avg60 34.880207
-inlet_flow_temperature_damped 39.431259
+inlet_flow_temperature_damped 35.255993
-inlet_flow_temperature_pred60 36.078678
+inlet_flow_temperature_pred60 33.910374
-outdoor_temperature 14.687500
+outdoor_temperature 1.812500
-outdoor_temperature_avg10 14.662500
+outdoor_temperature_avg10 1.825000
-outdoor_temperature_avg60 14.646875
+outdoor_temperature_avg60 1.821875
-outdoor_temperature_damped 9.169084
+outdoor_temperature_damped 2.390663
-outdoor_temperature_pred60 14.660233
+outdoor_temperature_pred60 1.840263
-return_flow_temperature 39.937500
+return_flow_temperature 34.125000
-return_flow_temperature_avg10 40.087502
+return_flow_temperature_avg10 34.162498
-return_flow_temperature_avg60 41.146873
+return_flow_temperature_avg60 34.304165
-return_flow_temperature_damped 32.385151
+return_flow_temperature_damped 31.430506
-return_flow_temperature_pred60 37.311958
+return_flow_temperature_pred60 33.858772
 chamber_temperature_state 0
 outdoor_temperature_state 0
 inlet_flow_temperature_state 0
@@ -115,13 +73,13 @@ return_flow_temperature_state 0
 safety_state 0
 control_state 3
 control_current_weekday 5
-control_current_entry_time 17100
+control_current_entry_time 24300
 control_current_entry_chamber_temperature 80.000000
 control_current_entry_return_flow_temperature 30.000000
 sntp_state 0
-system_unixtime 1762012743
+system_unixtime 1768067412
-uptime_seconds 465229
+uptime_seconds 344878
-wifi_rssi -72
+wifi_rssi -59
 ```
 
 #### Status Encoding
@@ -180,4 +138,20 @@ wifi_rssi -72
 | Input Burner Fault                    | IO19  | Digital Input IN1 |
 | Input Temperature DS10B20             | IO04  | 1-Wire            |
 
+## Configuration
 
+All parameters configurable via `idf.py menuconfig`:
+- WiFi credentials and static IP
+- GPIO pin assignments
+- 1-Wire sensor addresses
+- Temperature thresholds and limits
+- Heating schedule (day/night per weekday)
+- Damping factors
+
+## Building
+
+```bash
+idf.py set-target esp32
+idf.py menuconfig  # Configure settings
+idf.py build flash monitor
+```

main/Kconfig.projbuild

@@ -1,22 +1,391 @@
 menu "Smart Oil Heating Control System"
 
+    menu "WiFi Configuration"
         config SSID
-        string "SSID"
+            string "WiFi SSID"
             default "my WiFi SSID"
+            help
+                The SSID of the WiFi network to connect to.
+
         config WIFI_PASSWORD
-        string "WIFI_PASSWORD"
+            string "WiFi Password"
             default "my WIFI Password"
+            help
+                The password for the WiFi network.
+
         config STATIC_IP_ADDR
             string "Static IPv4 address"
             default "192.168.0.42"
+            help
+                Static IP address for the ESP32.
+
         config STATIC_IP_NETMASK
             string "Static IPv4 netmask"
             default "255.255.0.0"
+            help
+                Network mask for the static IP configuration.
+
         config STATIC_GATEWAY_IP_ADDR
             string "Static IPv4 gateway address"
             default "192.168.0.1"
+            help
+                Gateway IP address for network routing.
+
         config SNTP_SERVER_IP_ADDR
-        string "SNTP IPv4 server address"
+            string "SNTP server address"
             default "192.168.0.1"
+            help
+                NTP server address for time synchronization.
+    endmenu
+
+    menu "GPIO Configuration"
+        menu "Input GPIOs"
+            config GPIO_BURNER_FAULT
+                int "Burner fault input GPIO"
+                range 0 39
+                default 19
+                help
+                    GPIO pin connected to the burner fault signal.
+
+            config GPIO_DS18B20_ONEWIRE
+                int "DS18B20 1-Wire bus GPIO"
+                range 0 39
+                default 4
+                help
+                    GPIO pin for the 1-Wire bus (DS18B20 temperature sensors).
+        endmenu
+
+        menu "Output GPIOs"
+            config GPIO_CIRCULATION_PUMP
+                int "Circulation pump output GPIO"
+                range 0 39
+                default 27
+                help
+                    GPIO pin to control the circulation pump relay.
+
+            config GPIO_BURNER
+                int "Burner control output GPIO"
+                range 0 39
+                default 14
+                help
+                    GPIO pin to control the burner relay.
+
+            config GPIO_SAFETY_CONTACT
+                int "Safety contact output GPIO"
+                range 0 39
+                default 12
+                help
+                    GPIO pin for the safety contact relay (main power to burner).
+        endmenu
+    endmenu
+
+    menu "1-Wire Sensor Addresses"
+        config ONEWIRE_ADDR_CHAMBER_TEMP
+            hex "Chamber temperature sensor address"
+            default 0xd00000108cd01d28
+            help
+                64-bit 1-Wire address of the chamber temperature sensor.
+
+        config ONEWIRE_ADDR_OUTDOOR_TEMP
+            hex "Outdoor temperature sensor address"
+            default 0xd70000108a9b9128
+            help
+                64-bit 1-Wire address of the outdoor temperature sensor.
+
+        config ONEWIRE_ADDR_INLET_FLOW_TEMP
+            hex "Inlet flow temperature sensor address"
+            default 0x410000108b8c0628
+            help
+                64-bit 1-Wire address of the inlet flow temperature sensor.
+
+        config ONEWIRE_ADDR_RETURN_FLOW_TEMP
+            hex "Return flow temperature sensor address"
+            default 0x90000108cc77c28
+            help
+                64-bit 1-Wire address of the return flow temperature sensor.
+    endmenu
+
+    menu "Temperature Control Settings"
+        menu "Target Temperatures"
+            config TEMP_RETURN_FLOW_LOWER_LIMIT_DAY
+                int "Return flow lower limit (day) [°C x 10]"
+                range 150 500
+                default 300
+                help
+                    Minimum return flow temperature during day mode in 0.1°C units.
+                    Example: 300 = 30.0°C
+
+            config TEMP_RETURN_FLOW_LOWER_LIMIT_NIGHT
+                int "Return flow lower limit (night) [°C x 10]"
+                range 150 500
+                default 250
+                help
+                    Minimum return flow temperature during night mode in 0.1°C units.
+                    Example: 250 = 25.0°C
+
+            config TEMP_CHAMBER_TARGET
+                int "Chamber target temperature [°C x 10]"
+                range 500 950
+                default 800
+                help
+                    Maximum chamber temperature target in 0.1°C units.
+                    Example: 800 = 80.0°C
+
+            config TEMP_CHAMBER_THRESHOLD
+                int "Chamber temperature threshold [°C x 10]"
+                range 300 700
+                default 450
+                help
+                    Minimum chamber temperature to enable burner in 0.1°C units.
+                    Example: 450 = 45.0°C
+
+            config TEMP_CIRCULATION_PUMP_THRESHOLD
+                int "Circulation pump threshold [°C x 10]"
+                range 200 500
+                default 300
+                help
+                    Minimum chamber temperature to enable circulation pump in 0.1°C units.
+                    Example: 300 = 30.0°C
+        endmenu
+
+        menu "Summer Mode Settings"
+            config TEMP_SUMMER_MODE_HIGH
+                int "Summer mode activation threshold [°C x 10]"
+                range 150 300
+                default 200
+                help
+                    Outdoor temperature above which summer mode activates in 0.1°C units.
+                    Example: 200 = 20.0°C
+
+            config TEMP_SUMMER_MODE_LOW
+                int "Summer mode deactivation threshold [°C x 10]"
+                range 100 250
+                default 150
+                help
+                    Outdoor temperature below which summer mode deactivates in 0.1°C units.
+                    Example: 150 = 15.0°C
+        endmenu
+
+        config BURNER_FAULT_DETECTION_SECONDS
+            int "Burner fault detection timeout (seconds)"
+            range 60 600
+            default 240
+            help
+                Time in seconds to wait before checking for burner fault after enabling.
+    endmenu
+
+    menu "Sensor Limits"
+        menu "Chamber Temperature Limits"
+            config SENSOR_LIMIT_CHAMBER_MAX
+                int "Chamber sensor maximum [°C x 10]"
+                range 500 1200
+                default 950
+                help
+                    Maximum valid chamber temperature reading in 0.1°C units.
+
+            config SENSOR_LIMIT_CHAMBER_MIN
+                int "Chamber sensor minimum [°C x 10]"
+                range -400 100
+                default -100
+                help
+                    Minimum valid chamber temperature reading in 0.1°C units.
+        endmenu
+
+        menu "Outdoor Temperature Limits"
+            config SENSOR_LIMIT_OUTDOOR_MAX
+                int "Outdoor sensor maximum [°C x 10]"
+                range 300 600
+                default 450
+                help
+                    Maximum valid outdoor temperature reading in 0.1°C units.
+
+            config SENSOR_LIMIT_OUTDOOR_MIN
+                int "Outdoor sensor minimum [°C x 10]"
+                range -500 0
+                default -200
+                help
+                    Minimum valid outdoor temperature reading in 0.1°C units.
+        endmenu
+
+        menu "Inlet Flow Temperature Limits"
+            config SENSOR_LIMIT_INLET_MAX
+                int "Inlet flow sensor maximum [°C x 10]"
+                range 500 1200
+                default 950
+                help
+                    Maximum valid inlet flow temperature reading in 0.1°C units.
+
+            config SENSOR_LIMIT_INLET_MIN
+                int "Inlet flow sensor minimum [°C x 10]"
+                range -400 100
+                default -100
+                help
+                    Minimum valid inlet flow temperature reading in 0.1°C units.
+        endmenu
+
+        menu "Return Flow Temperature Limits"
+            config SENSOR_LIMIT_RETURN_MAX
+                int "Return flow sensor maximum [°C x 10]"
+                range 500 1200
+                default 950
+                help
+                    Maximum valid return flow temperature reading in 0.1°C units.
+
+            config SENSOR_LIMIT_RETURN_MIN
+                int "Return flow sensor minimum [°C x 10]"
+                range -400 100
+                default -100
+                help
+                    Minimum valid return flow temperature reading in 0.1°C units.
+        endmenu
+
+        config SENSOR_GRACE_PERIOD_MINUTES
+            int "Sensor unchanged grace period (minutes)"
+            range 1 120
+            default 30
+            help
+                Maximum time in minutes a sensor can report unchanged values
+                before being flagged as faulty.
+    endmenu
+
+    menu "Damping Factors"
+        config DAMPING_FACTOR_WARMER
+            int "Damping factor warmer [x 0.00001]"
+            range 1 100
+            default 1
+            help
+                Damping factor for rising temperatures in units of 0.00001.
+                Example: 1 = 0.00001 (0.001%)
+
+        config DAMPING_FACTOR_COLDER
+            int "Damping factor colder [x 0.00001]"
+            range 1 100
+            default 5
+            help
+                Damping factor for falling temperatures in units of 0.00001.
+                Example: 5 = 0.00005 (0.005%)
+    endmenu
+
+    menu "Heating Schedule"
+        menu "Weekday Schedule (Monday-Thursday)"
+            config SCHEDULE_WEEKDAY_DAY_START_HOUR
+                int "Day mode start hour"
+                range 0 23
+                default 4
+                help
+                    Hour when day mode starts on weekdays (24h format).
+
+            config SCHEDULE_WEEKDAY_DAY_START_MINUTE
+                int "Day mode start minute"
+                range 0 59
+                default 45
+                help
+                    Minute when day mode starts on weekdays.
+
+            config SCHEDULE_WEEKDAY_NIGHT_START_HOUR
+                int "Night mode start hour"
+                range 0 23
+                default 22
+                help
+                    Hour when night mode starts on weekdays (24h format).
+
+            config SCHEDULE_WEEKDAY_NIGHT_START_MINUTE
+                int "Night mode start minute"
+                range 0 59
+                default 0
+                help
+                    Minute when night mode starts on weekdays.
+        endmenu
+
+        menu "Friday Schedule"
+            config SCHEDULE_FRIDAY_DAY_START_HOUR
+                int "Day mode start hour"
+                range 0 23
+                default 4
+                help
+                    Hour when day mode starts on Friday (24h format).
+
+            config SCHEDULE_FRIDAY_DAY_START_MINUTE
+                int "Day mode start minute"
+                range 0 59
+                default 45
+                help
+                    Minute when day mode starts on Friday.
+
+            config SCHEDULE_FRIDAY_NIGHT_START_HOUR
+                int "Night mode start hour"
+                range 0 23
+                default 23
+                help
+                    Hour when night mode starts on Friday (24h format).
+
+            config SCHEDULE_FRIDAY_NIGHT_START_MINUTE
+                int "Night mode start minute"
+                range 0 59
+                default 0
+                help
+                    Minute when night mode starts on Friday.
+        endmenu
+
+        menu "Saturday Schedule"
+            config SCHEDULE_SATURDAY_DAY_START_HOUR
+                int "Day mode start hour"
+                range 0 23
+                default 6
+                help
+                    Hour when day mode starts on Saturday (24h format).
+
+            config SCHEDULE_SATURDAY_DAY_START_MINUTE
+                int "Day mode start minute"
+                range 0 59
+                default 45
+                help
+                    Minute when day mode starts on Saturday.
+
+            config SCHEDULE_SATURDAY_NIGHT_START_HOUR
+                int "Night mode start hour"
+                range 0 23
+                default 23
+                help
+                    Hour when night mode starts on Saturday (24h format).
+
+            config SCHEDULE_SATURDAY_NIGHT_START_MINUTE
+                int "Night mode start minute"
+                range 0 59
+                default 30
+                help
+                    Minute when night mode starts on Saturday.
+        endmenu
+
+        menu "Sunday Schedule"
+            config SCHEDULE_SUNDAY_DAY_START_HOUR
+                int "Day mode start hour"
+                range 0 23
+                default 6
+                help
+                    Hour when day mode starts on Sunday (24h format).
+
+            config SCHEDULE_SUNDAY_DAY_START_MINUTE
+                int "Day mode start minute"
+                range 0 59
+                default 45
+                help
+                    Minute when day mode starts on Sunday.
+
+            config SCHEDULE_SUNDAY_NIGHT_START_HOUR
+                int "Night mode start hour"
+                range 0 23
+                default 22
+                help
+                    Hour when night mode starts on Sunday (24h format).
+
+            config SCHEDULE_SUNDAY_NIGHT_START_MINUTE
+                int "Night mode start minute"
+                range 0 59
+                default 30
+                help
+                    Minute when night mode starts on Sunday.
+        endmenu
+    endmenu
 
 endmenu

main/control.c

@@ -1,134 +1,145 @@
+/**
+ * @file control.c
+ * @brief Implementation of heating control module.
+ */
+
 #include "control.h"
-#include "esp_log.h"
-#include "esp_timer.h"
-#include "freertos/FreeRTOS.h"
-#include "freertos/task.h"
 #include "inputs.h"
 #include "outputs.h"
 #include "safety.h"
 #include "sntp.h"
 
-#define PERIODIC_INTERVAL 1U // Run control loop every 1 second
+#include "esp_log.h"
+#include "esp_timer.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
 
-// Temperature thresholds
+#include <time.h>
-#define RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY 30.0f
-#define RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT 25.0f
-#define CHAMBER_TEMPERATURE_TARGET 80.0f    // Max cutoff temperature
-#define CHAMBER_TEMPERATURE_THRESHOLD 45.0f // Min threshold for burner enable
-#define SUMMER_MODE_TEMPERATURE_THRESHOLD_HIGH \
-    20.0f // Summer mode will be activated
-#define SUMMER_MODE_TEMPERATURE_THRESHOLD_LOW \
-    15.0f // Summer mode will be deactivated --> Heating starts
-#define CIRCULATION_PUMP_TEMPERATURE_THRESHOLD \
-    30.0f // Min threshold of chamber for circulation pump enable
-#define BURNER_FAULT_DETECTION_THRESHOLD \
-    (60U * 4U) // Burner fault detection after 4 minutes
 
-static const char *TAG = "smart-oil-heater-control-system-control";
+/** @brief Task interval in seconds. */
-static eControlState sControlState = CONTROL_STARTING;
+#define PERIODIC_INTERVAL 1U
-// Control table for daily schedules
+
-static const sControlDay aControlTable[] = {
+static const char *TAG = "control";
+
+static eControlState gControlState = CONTROL_STARTING;
+
+/** @brief Weekly schedule table (from Kconfig). */
+static const sControlDay gControlTable[] = {
     {MONDAY,
      2U,
-     {{{4, 45},
+     {{{CONFIG_SCHEDULE_WEEKDAY_DAY_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{22, 0},
+      {{CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
     {TUESDAY,
      2U,
-     {{{4, 45},
+     {{{CONFIG_SCHEDULE_WEEKDAY_DAY_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{22, 0},
+      {{CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
     {WEDNESDAY,
      2U,
-     {{{4, 45},
+     {{{CONFIG_SCHEDULE_WEEKDAY_DAY_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{22, 0},
+      {{CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
     {THURSDAY,
      2U,
-     {{{4, 45},
+     {{{CONFIG_SCHEDULE_WEEKDAY_DAY_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{22, 0},
+      {{CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_WEEKDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
     {FRIDAY,
      2U,
-     {{{4, 45},
+     {{{CONFIG_SCHEDULE_FRIDAY_DAY_START_HOUR, CONFIG_SCHEDULE_FRIDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{23, 0},
+      {{CONFIG_SCHEDULE_FRIDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_FRIDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
     {SATURDAY,
      2U,
-     {{{6, 45},
+     {{{CONFIG_SCHEDULE_SATURDAY_DAY_START_HOUR, CONFIG_SCHEDULE_SATURDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{23, 30},
+      {{CONFIG_SCHEDULE_SATURDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_SATURDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
     {SUNDAY,
      2U,
-     {{{6, 45},
+     {{{CONFIG_SCHEDULE_SUNDAY_DAY_START_HOUR, CONFIG_SCHEDULE_SUNDAY_DAY_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY,
        CHAMBER_TEMPERATURE_TARGET},
-      {{22, 30},
+      {{CONFIG_SCHEDULE_SUNDAY_NIGHT_START_HOUR, CONFIG_SCHEDULE_SUNDAY_NIGHT_START_MINUTE},
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
 };
-static sControlTemperatureEntry currentControlEntry =
-    aControlTable[0].aTemperatureEntries[0];
 
-// Function prototypes
+static sControlTemperatureEntry gCurrentControlEntry =
-void taskControl(void *pvParameters);
+    gControlTable[0].aTemperatureEntries[0];
-void findControlCurrentTemperatureEntry(void);
+static SemaphoreHandle_t xMutexAccessControl = NULL;
 
-void initControl(void)
+/* Private function prototypes */
+static void taskControl(void *pvParameters);
+static void findControlCurrentTemperatureEntry(void);
+static void setControlState(eControlState state);
+
+esp_err_t initControl(void)
 {
-    BaseType_t taskCreated =
+    xMutexAccessControl = xSemaphoreCreateRecursiveMutex();
-        xTaskCreate(taskControl,   // Function to implement the task
+    if (xMutexAccessControl == NULL)
-                    "taskControl", // Task name
-                    8192,          // Stack size (in words, not bytes)
-                    NULL,          // Parameters to the task function (none in this case)
-                    5,             // Task priority (higher number = higher priority)
-                    NULL           // Task handle (optional)
-        );
-
-    if (taskCreated == pdPASS)
     {
-        ESP_LOGI(TAG, "Task created successfully!");
+        ESP_LOGE(TAG, "Failed to create mutex");
+        return ESP_FAIL;
     }
-    else
+    xSemaphoreGiveRecursive(xMutexAccessControl);
+
+    BaseType_t taskCreated = xTaskCreate(
+        taskControl,
+        "taskControl",
+        8192,
+        NULL,
+        5,
+        NULL);
+
+    if (taskCreated != pdPASS)
     {
         ESP_LOGE(TAG, "Failed to create task");
-    }
+        return ESP_FAIL;
     }
 
-void taskControl(void *pvParameters)
+    ESP_LOGI(TAG, "Initialized successfully");
+    return ESP_OK;
+}
+
+/**
+ * @brief Main control task.
+ * @param pvParameters Task parameters (unused).
+ */
+static void taskControl(void *pvParameters)
 {
     bool bHeatingInAction = false;
     bool bSummerMode = false;
-    eBurnerState eBurnerState = BURNER_UNKNOWN;
+    eBurnerState burnerState = BURNER_UNKNOWN;
     int64_t i64BurnerEnableTimestamp = esp_timer_get_time();
 
     while (1)
     {
         vTaskDelay(PERIODIC_INTERVAL * 1000U / portTICK_PERIOD_MS);
 
-        // Check for safety faults
+        /* Check for safety faults */
         if (getSafetyState() != SAFETY_NO_ERROR)
         {
             ESP_LOGW(TAG, "Control not possible due to safety fault!");
-            sControlState = CONTROL_FAULT_SAFETY;
+            setControlState(CONTROL_FAULT_SAFETY);
             if (bHeatingInAction)
             {
                 ESP_LOGW(TAG, "Disabling burner due to safety fault");
@@ -139,11 +150,11 @@ void taskControl(void *pvParameters)
             continue;
         }
 
-        // Check for SNTP faults
+        /* Check for SNTP faults */
         if (getSntpState() != SYNC_SUCCESSFUL)
         {
             ESP_LOGW(TAG, "Control not possible due to SNTP fault!");
-            sControlState = CONTROL_FAULT_SNTP;
+            setControlState(CONTROL_FAULT_SNTP);
             if (bHeatingInAction)
             {
                 ESP_LOGW(TAG, "Disabling burner due to SNTP fault");
@@ -155,59 +166,51 @@ void taskControl(void *pvParameters)
         }
 
         findControlCurrentTemperatureEntry();
-        sControlTemperatureEntry currentControlEntry =
-            getControlCurrentTemperatureEntry();
 
-        if (getOutdoorTemperature().fDampedValue >=
+        /* Summer mode hysteresis */
-            SUMMER_MODE_TEMPERATURE_THRESHOLD_HIGH)
+        if (getOutdoorTemperature().fDampedValue >= SUMMER_MODE_TEMPERATURE_THRESHOLD_HIGH)
         {
             bSummerMode = true;
         }
-        else if (getOutdoorTemperature().fDampedValue <=
+        else if (getOutdoorTemperature().fDampedValue <= SUMMER_MODE_TEMPERATURE_THRESHOLD_LOW)
-                 SUMMER_MODE_TEMPERATURE_THRESHOLD_LOW)
         {
             bSummerMode = false;
         }
 
-        // Enable burner if outdoor temperature is low and return flow temperature
+        /* Enable burner if needed */
-        // is cooled down
+        if (!bHeatingInAction && (burnerState != BURNER_FAULT))
-        if (!bHeatingInAction && (eBurnerState != BURNER_FAULT))
         {
             if (bSummerMode)
             {
-                // ESP_LOGI(TAG, "Outdoor temperature too warm: Disabling heating");
                 setBurnerState(DISABLED);
                 setSafetyControlState(DISABLED);
-                sControlState = CONTROL_OUTDOOR_TOO_WARM;
+                setControlState(CONTROL_OUTDOOR_TOO_WARM);
             }
             else if ((getReturnFlowTemperature().average60s.fValue <=
-                      currentControlEntry.fReturnFlowTemperature) &&
+                      getControlCurrentTemperatureEntry().fReturnFlowTemperature) &&
-                     (getChamberTemperature().fCurrentValue <=
+                     (getChamberTemperature().fCurrentValue <= CHAMBER_TEMPERATURE_THRESHOLD))
-                      CHAMBER_TEMPERATURE_THRESHOLD))
             {
-                ESP_LOGI(TAG,
+                ESP_LOGI(TAG, "Enabling burner: Return flow temperature target reached");
-                         "Enabling burner: Return flow temperature target reached");
+                burnerState = BURNER_UNKNOWN;
-                eBurnerState = BURNER_UNKNOWN;
                 bHeatingInAction = true;
                 setBurnerState(ENABLED);
                 setSafetyControlState(ENABLED);
                 i64BurnerEnableTimestamp = esp_timer_get_time();
-                sControlState = CONTROL_HEATING;
+                setControlState(CONTROL_HEATING);
             }
             else
             {
-                // ESP_LOGI(TAG, "Return flow temperature too warm: Disabling heating");
+                setControlState(CONTROL_RETURN_FLOW_TOO_WARM);
-                sControlState = CONTROL_RETURN_FLOW_TOO_WARM;
             }
         }
 
-        // Disable burner if target temperature is reached or a fault occurred
+        /* Disable burner if target reached or fault */
         if (bHeatingInAction)
         {
             if ((getChamberTemperature().fCurrentValue >=
-                 currentControlEntry.fChamberTemperature) ||
+                 getControlCurrentTemperatureEntry().fChamberTemperature) ||
                 (getChamberTemperature().predict60s.fValue >=
-                 currentControlEntry.fChamberTemperature))
+                 getControlCurrentTemperatureEntry().fChamberTemperature))
             {
                 ESP_LOGI(TAG, "Chamber target temperature reached: Disabling burner");
                 bHeatingInAction = false;
@@ -217,14 +220,14 @@ void taskControl(void *pvParameters)
             else if (esp_timer_get_time() - i64BurnerEnableTimestamp >=
                      BURNER_FAULT_DETECTION_THRESHOLD * 1000000U)
             {
-                if (eBurnerState == BURNER_UNKNOWN)
+                if (burnerState == BURNER_UNKNOWN)
                 {
                     if (getBurnerError() == FAULT)
                     {
                         // ESP_LOGW(TAG, "Burner fault detected: Disabling burner");
                         bHeatingInAction = false;
-                        eBurnerState = BURNER_FAULT;
+                        burnerState = BURNER_FAULT;
-                        sControlState = CONTROL_FAULT_BURNER;
+                        setControlState(CONTROL_FAULT_BURNER);
                         setBurnerState(DISABLED);
                         setSafetyControlState(ENABLED);
                     }
@@ -232,15 +235,14 @@ void taskControl(void *pvParameters)
                     {
                         // ESP_LOGI(TAG, "No burner fault detected: Marking burner as
                         // fired");
-                        eBurnerState = BURNER_FIRED;
+                        burnerState = BURNER_FIRED;
                     }
                 }
             }
         }
 
-        // Manage circulation pump
+        /* Manage circulation pump */
-        if (getChamberTemperature().fCurrentValue <=
+        if (getChamberTemperature().fCurrentValue <= CIRCULATION_PUMP_TEMPERATURE_THRESHOLD)
-            CIRCULATION_PUMP_TEMPERATURE_THRESHOLD)
         {
             // ESP_LOGI(TAG, "Burner cooled down: Disabling circulation pump");
             setCirculationPumpState(DISABLED);
@@ -253,39 +255,58 @@ void taskControl(void *pvParameters)
     } // End of while(1)
 }
 
-eControlState getControlState(void) { return sControlState; }
+/**
+ * @brief Set the control state with mutex protection.
+ * @param state New control state.
+ */
+static void setControlState(eControlState state)
+{
+    if (xSemaphoreTakeRecursive(xMutexAccessControl, pdMS_TO_TICKS(5000)) == pdTRUE)
+    {
+        gControlState = state;
+        xSemaphoreGiveRecursive(xMutexAccessControl);
+    }
+    else
+    {
+        ESP_LOGE(TAG, "Unable to take mutex: setControlState()");
+    }
+}
+
+eControlState getControlState(void)
+{
+    eControlState ret = CONTROL_FAULT_SAFETY;
+
+    if (xSemaphoreTakeRecursive(xMutexAccessControl, pdMS_TO_TICKS(5000)) == pdTRUE)
+    {
+        ret = gControlState;
+        xSemaphoreGiveRecursive(xMutexAccessControl);
+    }
+    else
+    {
+        ESP_LOGE(TAG, "Unable to take mutex: getControlState()");
+    }
+
+    return ret;
+}
 
 eControlWeekday getControlCurrentWeekday(void)
 {
     time_t now;
-    struct tm *timeinfo;
+    struct tm timeinfo;
-
     time(&now);
-    timeinfo = localtime(&now);
+    localtime_r(&now, &timeinfo);
 
-    int day = timeinfo->tm_wday;
+    int day = timeinfo.tm_wday;
     return (eControlWeekday)((day == 0) ? 6 : day - 1);
 }
 
 /**
- * @brief Finds the active temperature control entry for the current time.
+ * @brief Find the currently active temperature entry based on time.
- *
- * Searches through the weekly schedule to find the most recent entry
- * that should be active at the current date/time. Falls back to the
- * last entry in the week if no suitable entry is found.
  */
-/**
+static void findControlCurrentTemperatureEntry(void)
- * @brief Finds the active temperature control entry for the current time.
- *
- * Searches through the weekly schedule to find the most recent entry
- * that should be active at the current date/time. Falls back to the
- * last entry in the week if no suitable entry is found.
- */
-void findControlCurrentTemperatureEntry(void)
 {
     eControlWeekday currentDay = getControlCurrentWeekday();
 
-    // Get current time
     time_t now;
     struct tm timeinfo;
     time(&now);
@@ -294,12 +315,15 @@ void findControlCurrentTemperatureEntry(void)
     int currentHour = timeinfo.tm_hour;
     int currentMinute = timeinfo.tm_min;
 
+    if (xSemaphoreTakeRecursive(xMutexAccessControl, pdMS_TO_TICKS(5000)) == pdTRUE)
+    {
+
         // ESP_LOGI(TAG, "Searching for control entry - Day: %d, Time: %02d:%02d", currentDay, currentHour, currentMinute);
 
         // Search through all days and entries
         for (int dayIndex = 0; dayIndex < 7; dayIndex++)
         {
-        const sControlDay *day = &aControlTable[dayIndex];
+            const sControlDay *day = &gControlTable[dayIndex];
 
             for (int entryIndex = 0; entryIndex < day->entryCount; entryIndex++)
             {
@@ -314,31 +338,33 @@ void findControlCurrentTemperatureEntry(void)
 
                 if (isFutureDay || isTodayFutureTime)
                 {
+
                     // Found next scheduled entry, so determine the previous (active) one
                     if (entryIndex > 0)
                     {
                         // Use previous entry from same day
-                    currentControlEntry = day->aTemperatureEntries[entryIndex - 1];
+                        gCurrentControlEntry = day->aTemperatureEntries[entryIndex - 1];
                     }
                     else if (dayIndex > 0)
                     {
                         // Use last entry from previous day
-                    const sControlDay *previousDay = &aControlTable[dayIndex - 1];
+                        const sControlDay *previousDay = &gControlTable[dayIndex - 1];
-                    currentControlEntry = previousDay->aTemperatureEntries[previousDay->entryCount - 1];
+                        gCurrentControlEntry = previousDay->aTemperatureEntries[previousDay->entryCount - 1];
                     }
                     else
                     {
                         // First entry of the week - wrap to last entry of Sunday
-                    const sControlDay *sunday = &aControlTable[6];
+                        const sControlDay *sunday = &gControlTable[6];
-                    currentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
+                        gCurrentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
                     }
+                    xSemaphoreGiveRecursive(xMutexAccessControl);
                     /*
                     ESP_LOGI(TAG, "Active entry found - Time: %02d:%02d, "
                     "Return Temp: %lf, Chamber Temp: %lf",
-                         currentControlEntry.timestamp.hour,
+                    gCurrentControlEntry.timestamp.hour,
-                         currentControlEntry.timestamp.minute,
+                    gCurrentControlEntry.timestamp.minute,
-                         currentControlEntry.fReturnFlowTemperature,
+                    gCurrentControlEntry.fReturnFlowTemperature,
-                         currentControlEntry.fChamberTemperature);
+                    gCurrentControlEntry.fChamberTemperature);
                     */
                     return;
                 }
@@ -347,13 +373,30 @@ void findControlCurrentTemperatureEntry(void)
 
         // If we reached here, current time is after all entries this week
         // Use the last entry (Sunday evening)
-    const sControlDay *sunday = &aControlTable[6];
+        const sControlDay *sunday = &gControlTable[6];
-    currentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
+        gCurrentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
 
-    // ESP_LOGI(TAG, "Using last entry of week - Time: %02d:%02d", currentControlEntry.timestamp.hour, currentControlEntry.timestamp.minute);
+        // ESP_LOGI(TAG, "Using last entry of week - Time: %02d:%02d", gCurrentControlEntry.timestamp.hour, gCurrentControlEntry.timestamp.minute);
+        xSemaphoreGiveRecursive(xMutexAccessControl);
+    }
+    else
+    {
+        ESP_LOGE(TAG, "Unable to take mutex: findControlCurrentTemperatureEntry()");
+    }
 }
 
 sControlTemperatureEntry getControlCurrentTemperatureEntry(void)
 {
-    return currentControlEntry;
+    sControlTemperatureEntry ret = gControlTable[0].aTemperatureEntries[0];
+    if (xSemaphoreTakeRecursive(xMutexAccessControl, pdMS_TO_TICKS(5000)) == pdTRUE)
+    {
+        ret = gCurrentControlEntry;
+        xSemaphoreGiveRecursive(xMutexAccessControl);
+    }
+    else
+    {
+        ESP_LOGE(TAG, "Unable to take mutex: getControlCurrentTemperatureEntry()");
+    }
+
+    return ret;
 }

main/control.h

@@ -1,26 +1,74 @@
-#pragma once
+/**
-#include <time.h>
+ * @file control.h
+ * @brief Heating control logic with schedule-based temperature management.
+ *
+ * This module implements the main heating control loop. It manages
+ * burner operation based on time schedules, temperature targets,
+ * and summer mode detection.
+ */
 
+#pragma once
+
+#include "sdkconfig.h"
+#include "esp_err.h"
+
+#include <stdint.h>
+#include <stddef.h>
+
+/** @brief Maximum number of temperature entries per day. */
 #define MAX_TEMPERATURE_ENTRIES_PER_DAY 24U
 
+/** @brief Return flow target temperature for day mode (°C). */
+#define RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_DAY (CONFIG_TEMP_RETURN_FLOW_LOWER_LIMIT_DAY / 10.0f)
+
+/** @brief Return flow target temperature for night mode (°C). */
+#define RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT (CONFIG_TEMP_RETURN_FLOW_LOWER_LIMIT_NIGHT / 10.0f)
+
+/** @brief Chamber target temperature (°C). */
+#define CHAMBER_TEMPERATURE_TARGET (CONFIG_TEMP_CHAMBER_TARGET / 10.0f)
+
+/** @brief Chamber temperature threshold to enable burner (°C). */
+#define CHAMBER_TEMPERATURE_THRESHOLD (CONFIG_TEMP_CHAMBER_THRESHOLD / 10.0f)
+
+/** @brief Outdoor temperature to activate summer mode (°C). */
+#define SUMMER_MODE_TEMPERATURE_THRESHOLD_HIGH (CONFIG_TEMP_SUMMER_MODE_HIGH / 10.0f)
+
+/** @brief Outdoor temperature to deactivate summer mode (°C). */
+#define SUMMER_MODE_TEMPERATURE_THRESHOLD_LOW (CONFIG_TEMP_SUMMER_MODE_LOW / 10.0f)
+
+/** @brief Chamber temperature threshold for circulation pump (°C). */
+#define CIRCULATION_PUMP_TEMPERATURE_THRESHOLD (CONFIG_TEMP_CIRCULATION_PUMP_THRESHOLD / 10.0f)
+
+/** @brief Time to wait before checking burner fault (seconds). */
+#define BURNER_FAULT_DETECTION_THRESHOLD CONFIG_BURNER_FAULT_DETECTION_SECONDS
+
+/**
+ * @brief Control state enumeration.
+ */
 typedef enum _ControlState
 {
-    CONTROL_STARTING,
+    CONTROL_STARTING,             /**< System starting up. */
-    CONTROL_HEATING,
+    CONTROL_HEATING,              /**< Burner running. */
-    CONTROL_OUTDOOR_TOO_WARM,
+    CONTROL_OUTDOOR_TOO_WARM,     /**< Summer mode active. */
-    CONTROL_RETURN_FLOW_TOO_WARM,
+    CONTROL_RETURN_FLOW_TOO_WARM, /**< Target temperature reached. */
-    CONTROL_FAULT_BURNER,
+    CONTROL_FAULT_BURNER,         /**< Burner fault detected. */
-    CONTROL_FAULT_SAFETY,
+    CONTROL_FAULT_SAFETY,         /**< Safety fault detected. */
-    CONTROL_FAULT_SNTP,
+    CONTROL_FAULT_SNTP,           /**< SNTP sync failed. */
 } eControlState;
 
+/**
+ * @brief Burner operational state enumeration.
+ */
 typedef enum _BurnerState
 {
-    BURNER_UNKNOWN, // Burner is disabled or state after enabling is still unkown
+    BURNER_UNKNOWN, /**< Burner state unknown after enable. */
-    BURNER_FIRED,   // Burner fired successfully
+    BURNER_FIRED,   /**< Burner fired successfully. */
-    BURNER_FAULT    // Burner was unable to fire successfully
+    BURNER_FAULT    /**< Burner failed to fire. */
 } eBurnerState;
 
+/**
+ * @brief Weekday enumeration (Monday = 0).
+ */
 typedef enum _ControlWeekday
 {
     MONDAY,
@@ -32,27 +80,58 @@ typedef enum _ControlWeekday
     SUNDAY,
 } eControlWeekday;
 
+/**
+ * @brief Time of day structure.
+ */
 typedef struct _ControlTimestamp
 {
-    uint8_t hour;
+    uint8_t hour;   /**< Hour (0-23). */
-    uint8_t minute;
+    uint8_t minute; /**< Minute (0-59). */
 } sControlTimestamp;
 
+/**
+ * @brief Temperature schedule entry.
+ */
 typedef struct _ControlTemperatureEntry
 {
-    sControlTimestamp timestamp;
+    sControlTimestamp timestamp;  /**< Time when entry becomes active. */
-    float fReturnFlowTemperature;
+    float fReturnFlowTemperature; /**< Target return flow temperature. */
-    float fChamberTemperature;
+    float fChamberTemperature;    /**< Target chamber temperature. */
 } sControlTemperatureEntry;
 
+/**
+ * @brief Daily schedule structure.
+ */
 typedef struct _ControlDay
 {
-    eControlWeekday day;
+    eControlWeekday day;                                                           /**< Day of week. */
-    size_t entryCount; // number of entries for each day
+    size_t entryCount;                                                             /**< Number of entries for this day. */
-    sControlTemperatureEntry aTemperatureEntries[MAX_TEMPERATURE_ENTRIES_PER_DAY];
+    sControlTemperatureEntry aTemperatureEntries[MAX_TEMPERATURE_ENTRIES_PER_DAY]; /**< Schedule entries. */
 } sControlDay;
 
-void initControl(void);
+/**
+ * @brief Initialize the control module.
+ *
+ * Creates the control task that manages heating operation.
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initControl(void);
+
+/**
+ * @brief Get the current control state.
+ * @return eControlState indicating current operation mode.
+ */
 eControlState getControlState(void);
+
+/**
+ * @brief Get the current weekday.
+ * @return eControlWeekday (Monday = 0, Sunday = 6).
+ */
 eControlWeekday getControlCurrentWeekday(void);
+
+/**
+ * @brief Get the currently active temperature entry.
+ * @return sControlTemperatureEntry with current targets.
+ */
 sControlTemperatureEntry getControlCurrentTemperatureEntry(void);

main/inputs.c

@@ -1,29 +1,51 @@
-#include "freertos/FreeRTOS.h"
+/**
-#include "freertos/task.h"
+ * @file inputs.c
-#include "driver/gpio.h"
+ * @brief Implementation of input handling module.
-#include <string.h>
+ */
-#include <math.h>
-#include "esp_log.h"
-#include <ds18x20.h>
 
 #include "inputs.h"
 
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "driver/gpio.h"
+#include "esp_log.h"
+#include <ds18x20.h>
+
+#include <string.h>
+#include <math.h>
+
+/** @brief Maximum number of DS18B20 sensors supported. */
 #define MAX_DN18B20_SENSORS 4U
-#define ONE_WIRE_LOOPS 4U    // try to read the 1-Wire sensors that often
-#define PERIODIC_INTERVAL 1U // read and compute the inputs every 1sec
 
-static const char *TAG = "smart-oil-heater-control-system-inputs";
+/** @brief Number of retry attempts for 1-Wire read. */
-const uint8_t uBurnerFaultPin = 19U;
+#define ONE_WIRE_LOOPS 4U
-const uint8_t uDS18B20Pin = 4U;
 
-const onewire_addr_t uChamperTempSensorAddr = 0xd00000108cd01d28;
+/** @brief Task interval in seconds. */
-const onewire_addr_t uOutdoorTempSensorAddr = 0xd70000108a9b9128;
+#define PERIODIC_INTERVAL 1U
-const onewire_addr_t uInletFlowTempSensorAddr = 0x410000108b8c0628;
-const onewire_addr_t uReturnFlowTempSensorAddr = 0x90000108cc77c28;
 
-onewire_addr_t uOneWireAddresses[MAX_DN18B20_SENSORS];
+static const char *TAG = "inputs";
-float fDS18B20Temps[MAX_DN18B20_SENSORS];
+
-size_t sSensorCount = 0U;
+/** @brief Burner fault GPIO pin (from Kconfig). */
+static const uint8_t uBurnerFaultPin = CONFIG_GPIO_BURNER_FAULT;
+
+/** @brief DS18B20 1-Wire GPIO pin (from Kconfig). */
+static const uint8_t uDS18B20Pin = CONFIG_GPIO_DS18B20_ONEWIRE;
+
+/** @brief Chamber temperature sensor address (from Kconfig). */
+static const onewire_addr_t uChamperTempSensorAddr = CONFIG_ONEWIRE_ADDR_CHAMBER_TEMP;
+
+/** @brief Outdoor temperature sensor address (from Kconfig). */
+static const onewire_addr_t uOutdoorTempSensorAddr = CONFIG_ONEWIRE_ADDR_OUTDOOR_TEMP;
+
+/** @brief Inlet flow temperature sensor address (from Kconfig). */
+static const onewire_addr_t uInletFlowTempSensorAddr = CONFIG_ONEWIRE_ADDR_INLET_FLOW_TEMP;
+
+/** @brief Return flow temperature sensor address (from Kconfig). */
+static const onewire_addr_t uReturnFlowTempSensorAddr = CONFIG_ONEWIRE_ADDR_RETURN_FLOW_TEMP;
+
+static onewire_addr_t uOneWireAddresses[MAX_DN18B20_SENSORS];
+static float fDS18B20Temps[MAX_DN18B20_SENSORS];
+static size_t sSensorCount = 0U;
 
 static SemaphoreHandle_t xMutexAccessInputs = NULL;
 static eBurnerErrorState sBurnerErrorState;
@@ -32,29 +54,34 @@ static sMeasurement sOutdoorTemperature;
 static sMeasurement sInletFlowTemperature;
 static sMeasurement sReturnFlowTemperature;
 
-void taskInput(void *pvParameters);
+/* Private function prototypes */
-void initMeasurement(sMeasurement *pMeasurement);
+static void taskInput(void *pvParameters);
-void updateAverage(sMeasurement *pMeasurement);
+static void initMeasurement(sMeasurement *pMeasurement);
-void updatePrediction(sMeasurement *pMeasurement);
+static void updateAverage(sMeasurement *pMeasurement);
-float linearRegressionPredict(const float *samples, size_t count, size_t bufferIndex, float futureIndex);
+static void updatePrediction(sMeasurement *pMeasurement);
+static float linearRegressionPredict(const float *samples, size_t count, size_t bufferIndex, float futureIndex);
 
-void initInputs(void)
+esp_err_t initInputs(void)
 {
-
     gpio_config_t ioConfBurnerFault = {
-        .pin_bit_mask = (1ULL << uBurnerFaultPin), // Pin mask
+        .pin_bit_mask = (1ULL << uBurnerFaultPin),
-        .mode = GPIO_MODE_INPUT,                   // Set as inout
+        .mode = GPIO_MODE_INPUT,
-        .pull_up_en = GPIO_PULLUP_ENABLE,          // Enable pull-up
+        .pull_up_en = GPIO_PULLUP_ENABLE,
-        .pull_down_en = GPIO_PULLDOWN_DISABLE,     // Disable pull-down
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
-        .intr_type = GPIO_INTR_DISABLE             // Disable interrupts
+        .intr_type = GPIO_INTR_DISABLE};
-    };
 
-    gpio_config(&ioConfBurnerFault);
+    esp_err_t ret = gpio_config(&ioConfBurnerFault);
+    if (ret != ESP_OK)
+    {
+        ESP_LOGE(TAG, "GPIO config failed: %s", esp_err_to_name(ret));
+        return ESP_FAIL;
+    }
 
     xMutexAccessInputs = xSemaphoreCreateRecursiveMutex();
     if (xMutexAccessInputs == NULL)
     {
-        ESP_LOGE(TAG, "Unable to create mutex");
+        ESP_LOGE(TAG, "Failed to create mutex");
+        return ESP_FAIL;
     }
     xSemaphoreGiveRecursive(xMutexAccessInputs);
 
@@ -64,25 +91,28 @@ void initInputs(void)
     initMeasurement(&sReturnFlowTemperature);
 
     BaseType_t taskCreated = xTaskCreate(
-        taskInput,   // Function to implement the task
+        taskInput,
-        "taskInput", // Task name
+        "taskInput",
-        4096,        // Stack size (in words, not bytes)
+        4096,
-        NULL,        // Parameters to the task function (none in this case)
+        NULL,
-        5,           // Task priority (higher number = higher priority)
+        5,
-        NULL         // Task handle (optional)
+        NULL);
-    );
 
-    if (taskCreated == pdPASS)
+    if (taskCreated != pdPASS)
-    {
-        ESP_LOGI(TAG, "Task created successfully!");
-    }
-    else
     {
         ESP_LOGE(TAG, "Failed to create task");
-    }
+        return ESP_FAIL;
     }
 
-void initMeasurement(sMeasurement *pMeasurement)
+    ESP_LOGI(TAG, "Initialized successfully");
+    return ESP_OK;
+}
+
+/**
+ * @brief Initialize a measurement structure to default values.
+ * @param pMeasurement Pointer to measurement structure.
+ */
+static void initMeasurement(sMeasurement *pMeasurement)
 {
     if (!pMeasurement)
         return;
@@ -94,25 +124,29 @@ void initMeasurement(sMeasurement *pMeasurement)
     pMeasurement->average10s.fValue = INITIALISATION_VALUE;
     pMeasurement->average10s.bufferCount = 0U;
     pMeasurement->average10s.bufferIndex = 0U;
-    memset(pMeasurement->average10s.samples, 0U, AVG10S_SAMPLE_SIZE);
+    memset(pMeasurement->average10s.samples, 0U, sizeof(float) * AVG10S_SAMPLE_SIZE);
 
     pMeasurement->average60s.fValue = INITIALISATION_VALUE;
     pMeasurement->average60s.bufferCount = 0U;
     pMeasurement->average60s.bufferIndex = 0U;
-    memset(pMeasurement->average60s.samples, 0U, AVG60S_SAMPLE_SIZE);
+    memset(pMeasurement->average60s.samples, 0U, sizeof(float) * AVG60S_SAMPLE_SIZE);
 
     pMeasurement->predict60s.fValue = INITIALISATION_VALUE;
     pMeasurement->predict60s.bufferCount = 0U;
     pMeasurement->predict60s.bufferIndex = 0U;
-    memset(pMeasurement->predict60s.samples, 0U, PRED60S_SAMPLE_SIZE);
+    memset(pMeasurement->predict60s.samples, 0U, sizeof(float) * PRED60S_SAMPLE_SIZE);
 }
 
-void updateAverage(sMeasurement *pMeasurement)
+/**
+ * @brief Update average values and damped value for a measurement.
+ * @param pMeasurement Pointer to measurement structure.
+ */
+static void updateAverage(sMeasurement *pMeasurement)
 {
     if (!pMeasurement)
         return;
 
-    // Average form the last 10sec
+    /* 10-second average */
     pMeasurement->average10s.samples[pMeasurement->average10s.bufferIndex] = pMeasurement->fCurrentValue;
     pMeasurement->average10s.bufferIndex = (pMeasurement->average10s.bufferIndex + 1) % AVG10S_SAMPLE_SIZE;
 
@@ -122,14 +156,21 @@ void updateAverage(sMeasurement *pMeasurement)
     }
 
     float sum = 0.0;
-    for (int i = 0; i <= pMeasurement->average10s.bufferCount; i++)
+    for (int i = 0; i < pMeasurement->average10s.bufferCount; i++)
     {
         sum += pMeasurement->average10s.samples[i];
     }
 
+    if (pMeasurement->average10s.bufferCount == 0U)
+    {
+        pMeasurement->average10s.fValue = 0.0f;
+    }
+    else
+    {
         pMeasurement->average10s.fValue = sum / pMeasurement->average10s.bufferCount;
+    }
 
-    // Average form the last 60sec
+    /* 60-second average */
     pMeasurement->average60s.samples[pMeasurement->average60s.bufferIndex] = pMeasurement->fCurrentValue;
     pMeasurement->average60s.bufferIndex = (pMeasurement->average60s.bufferIndex + 1) % AVG60S_SAMPLE_SIZE;
 
@@ -144,9 +185,16 @@ void updateAverage(sMeasurement *pMeasurement)
         sum += pMeasurement->average60s.samples[i];
     }
 
+    if (pMeasurement->average60s.bufferCount == 0U)
+    {
+        pMeasurement->average60s.fValue = 0.0f;
+    }
+    else
+    {
         pMeasurement->average60s.fValue = sum / pMeasurement->average60s.bufferCount;
+    }
 
-    // Damped current value
+    /* Damped current value */
     if (pMeasurement->fDampedValue == INITIALISATION_VALUE)
     {
         pMeasurement->fDampedValue = pMeasurement->fCurrentValue;
@@ -165,7 +213,11 @@ void updateAverage(sMeasurement *pMeasurement)
     }
 }
 
-void updatePrediction(sMeasurement *pMeasurement)
+/**
+ * @brief Update 60-second prediction using linear regression.
+ * @param pMeasurement Pointer to measurement structure.
+ */
+static void updatePrediction(sMeasurement *pMeasurement)
 {
     if (!pMeasurement)
         return;
@@ -185,7 +237,11 @@ void updatePrediction(sMeasurement *pMeasurement)
         predict60s->bufferCount + 60.0f);
 }
 
-void taskInput(void *pvParameters)
+/**
+ * @brief Input task - reads sensors periodically.
+ * @param pvParameters Task parameters (unused).
+ */
+static void taskInput(void *pvParameters)
 {
     while (1)
     {
@@ -287,20 +343,27 @@ void taskInput(void *pvParameters)
     }
 }
 
-float linearRegressionPredict(const float *samples, size_t count, size_t bufferIndex, float futureIndex)
+/**
+ * @brief Predict future value using linear regression.
+ * @param samples Sample buffer.
+ * @param count Number of valid samples.
+ * @param bufferIndex Current buffer write index.
+ * @param futureIndex Future time index to predict.
+ * @return Predicted value.
+ */
+static float linearRegressionPredict(const float *samples, size_t count, size_t bufferIndex, float futureIndex)
 {
     if (count == 0)
-        return INITIALISATION_VALUE; // No prediction possible with no data
+        return INITIALISATION_VALUE;
 
     float sumX = INITIALISATION_VALUE, sumY = INITIALISATION_VALUE, sumXY = INITIALISATION_VALUE, sumX2 = INITIALISATION_VALUE;
 
     for (size_t i = 0; i < count; i++)
     {
-        // Calculate the circular buffer index for the current sample
         size_t circularIndex = (bufferIndex + i + 1) % count;
 
-        float x = (float)i;               // Time index
+        float x = (float)i;
-        float y = samples[circularIndex]; // Sample value
+        float y = samples[circularIndex];
 
         sumX += x;
         sumY += y;
@@ -308,15 +371,13 @@ float linearRegressionPredict(const float *samples, size_t count, size_t bufferI
         sumX2 += x * x;
     }
 
-    // Calculate slope (m) and intercept (b) of the line: y = mx + b
     float denominator = (count * sumX2 - sumX * sumX);
-    if (fabs(denominator) < 1e-6)    // Avoid division by zero
+    if (fabs(denominator) < 1e-6)
-        return samples[bufferIndex]; // Return the latest value as prediction
+        return samples[bufferIndex];
 
     float m = (count * sumXY - sumX * sumY) / denominator;
     float b = (sumY - m * sumX) / count;
 
-    // Predict value at futureIndex
     return m * futureIndex + b;
 }
 

main/inputs.h

@@ -1,55 +1,133 @@
+/**
+ * @file inputs.h
+ * @brief Input handling for temperature sensors and burner fault detection.
+ *
+ * This module reads DS18B20 temperature sensors via 1-Wire and monitors
+ * the burner fault input. It provides averaged, damped, and predicted
+ * temperature values.
+ */
+
 #pragma once
 
-#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#include "sdkconfig.h"
-#define INITIALISATION_VALUE 0.0f
-#define AVG10S_SAMPLE_SIZE 10U
-#define AVG60S_SAMPLE_SIZE 60U
-#define AVG24H_SAMPLE_SIZE 24U
-#define PRED60S_SAMPLE_SIZE 60U
-#define DAMPING_FACTOR_WARMER 0.00001f // 0.001%
-#define DAMPING_FACTOR_COLDER 0.00005f // 0.005%
 
+#include "esp_err.h"
+
+#include <stddef.h>
+
+/** @brief Returns the maximum of two values. */
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+
+/** @brief Initial value for measurements before first reading. */
+#define INITIALISATION_VALUE 0.0f
+
+/** @brief Sample buffer size for 10-second average. */
+#define AVG10S_SAMPLE_SIZE 10U
+
+/** @brief Sample buffer size for 60-second average. */
+#define AVG60S_SAMPLE_SIZE 60U
+
+/** @brief Sample buffer size for 24-hour average. */
+#define AVG24H_SAMPLE_SIZE 24U
+
+/** @brief Sample buffer size for 60-second prediction. */
+#define PRED60S_SAMPLE_SIZE 60U
+
+/** @brief Damping factor for rising temperatures (from Kconfig). */
+#define DAMPING_FACTOR_WARMER (CONFIG_DAMPING_FACTOR_WARMER * 0.00001f)
+
+/** @brief Damping factor for falling temperatures (from Kconfig). */
+#define DAMPING_FACTOR_COLDER (CONFIG_DAMPING_FACTOR_COLDER * 0.00001f)
+
+/**
+ * @brief Burner error state enumeration.
+ */
 typedef enum _BurnerErrorState
 {
-    NO_ERROR,
+    NO_ERROR, /**< No burner fault detected. */
-    FAULT
+    FAULT     /**< Burner fault signal active. */
 } eBurnerErrorState;
 
+/**
+ * @brief Measurement error state enumeration.
+ */
 typedef enum _MeasurementErrorState
 {
-    MEASUREMENT_NO_ERROR,
+    MEASUREMENT_NO_ERROR, /**< Measurement valid. */
-    MEASUREMENT_FAULT
+    MEASUREMENT_FAULT     /**< Measurement failed or sensor not found. */
 } eMeasurementErrorState;
 
+/**
+ * @brief Circular buffer for averaging temperature values.
+ */
 typedef struct _Average
 {
-    float fValue;
+    float fValue;                                                                        /**< Current average value. */
-    float samples[MAX(AVG10S_SAMPLE_SIZE, MAX(AVG60S_SAMPLE_SIZE, AVG24H_SAMPLE_SIZE))];
+    float samples[MAX(AVG10S_SAMPLE_SIZE, MAX(AVG60S_SAMPLE_SIZE, AVG24H_SAMPLE_SIZE))]; /**< Sample buffer. */
-    size_t bufferIndex;
+    size_t bufferIndex;                                                                  /**< Current write index. */
-    size_t bufferCount;
+    size_t bufferCount;                                                                  /**< Number of valid samples. */
 } sAverage;
 
+/**
+ * @brief Circular buffer for temperature prediction.
+ */
 typedef struct _Predict
 {
-    float fValue;
+    float fValue;                       /**< Predicted value. */
-    float samples[PRED60S_SAMPLE_SIZE];
+    float samples[PRED60S_SAMPLE_SIZE]; /**< Sample buffer. */
-    size_t bufferIndex;
+    size_t bufferIndex;                 /**< Current write index. */
-    size_t bufferCount;
+    size_t bufferCount;                 /**< Number of valid samples. */
 } sPredict;
 
+/**
+ * @brief Complete measurement data structure.
+ */
 typedef struct _Measurement
 {
-    float fCurrentValue;
+    float fCurrentValue;          /**< Current raw temperature value. */
-    float fDampedValue;
+    float fDampedValue;           /**< Damped temperature value. */
-    sAverage average10s;
+    sAverage average10s;          /**< 10-second rolling average. */
-    sAverage average60s;
+    sAverage average60s;          /**< 60-second rolling average. */
-    sPredict predict60s;
+    sPredict predict60s;          /**< 60-second prediction. */
-    eMeasurementErrorState state;
+    eMeasurementErrorState state; /**< Measurement state. */
 } sMeasurement;
 
-void initInputs(void);
+/**
+ * @brief Initialize the inputs module.
+ *
+ * Configures GPIO for burner fault input and starts the input task
+ * for reading DS18B20 temperature sensors.
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initInputs(void);
+
+/**
+ * @brief Get the current chamber temperature measurement.
+ * @return sMeasurement structure with current values and state.
+ */
 sMeasurement getChamberTemperature(void);
+
+/**
+ * @brief Get the current outdoor temperature measurement.
+ * @return sMeasurement structure with current values and state.
+ */
 sMeasurement getOutdoorTemperature(void);
+
+/**
+ * @brief Get the current inlet flow temperature measurement.
+ * @return sMeasurement structure with current values and state.
+ */
 sMeasurement getInletFlowTemperature(void);
+
+/**
+ * @brief Get the current return flow temperature measurement.
+ * @return sMeasurement structure with current values and state.
+ */
 sMeasurement getReturnFlowTemperature(void);
+
+/**
+ * @brief Get the current burner error state.
+ * @return eBurnerErrorState indicating fault status.
+ */
 eBurnerErrorState getBurnerError(void);

main/main.c

@@ -1,6 +1,10 @@
-#include "esp_log.h"
+/**
-#include <esp_system.h>
+ * @file main.c
-#include "nvs_flash.h"
+ * @brief Main entry point for Smart Oil Heating Control System.
+ *
+ * This file initializes all system modules and handles initialization
+ * errors by logging diagnostic information and triggering a reboot.
+ */
 
 #include "safety.h"
 #include "metrics.h"
@@ -10,29 +14,110 @@
 #include "wifi.h"
 #include "sntp.h"
 
-static const char *TAG = "smart-oil-heater-control-system";
+#include "esp_log.h"
+#include "esp_system.h"
+#include "nvs_flash.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
 
+static const char *TAG = "main";
+
+/** @brief Delay before reboot in milliseconds. */
+#define REBOOT_DELAY_MS 5000
+
+/**
+ * @brief Log error and trigger system reboot.
+ * @param module Name of the module that failed.
+ */
+static void reboot_on_error(const char *module)
+{
+    ESP_LOGE(TAG, "========================================");
+    ESP_LOGE(TAG, "FATAL: %s initialization failed!", module);
+    ESP_LOGE(TAG, "System will reboot in %d seconds...", REBOOT_DELAY_MS / 1000);
+    ESP_LOGE(TAG, "========================================");
+
+    vTaskDelay(pdMS_TO_TICKS(REBOOT_DELAY_MS));
+    esp_restart();
+}
+
+/**
+ * @brief Application main entry point.
+ */
 void app_main(void)
 {
-    ESP_LOGI(TAG, "starting ...");
+    ESP_LOGI(TAG, "========================================");
+    ESP_LOGI(TAG, "Smart Oil Heating Control System");
+    ESP_LOGI(TAG, "Starting initialization...");
+    ESP_LOGI(TAG, "========================================");
 
-    // Initialize NVS
+    /* Initialize NVS */
     esp_err_t ret = nvs_flash_init();
     if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND)
     {
+        ESP_LOGW(TAG, "NVS partition needs erase, erasing...");
         ESP_ERROR_CHECK(nvs_flash_erase());
         ret = nvs_flash_init();
     }
-    ESP_ERROR_CHECK(ret);
+    if (ret != ESP_OK)
+    {
+        ESP_LOGE(TAG, "NVS init failed: %s", esp_err_to_name(ret));
+        reboot_on_error("NVS");
+    }
+    ESP_LOGI(TAG, "[OK] NVS initialized");
 
-    // TODO: Error handling!
+    /* Initialize Outputs */
-    initOutputs();
+    if (initOutputs() != ESP_OK)
-    initInputs();
+    {
-    initSafety();
+        reboot_on_error("Outputs");
-    initWifi();
+    }
-    initSntp();
+    ESP_LOGI(TAG, "[OK] Outputs initialized");
-    initControl();
+
-    initMetrics();
+    /* Initialize Inputs */
+    if (initInputs() != ESP_OK)
+    {
+        reboot_on_error("Inputs");
+    }
+    ESP_LOGI(TAG, "[OK] Inputs initialized");
+
+    /* Initialize Safety */
+    if (initSafety() != ESP_OK)
+    {
+        reboot_on_error("Safety");
+    }
+    ESP_LOGI(TAG, "[OK] Safety initialized");
+
+    /* Initialize WiFi */
+    if (initWifi() != ESP_OK)
+    {
+        reboot_on_error("WiFi");
+    }
+    ESP_LOGI(TAG, "[OK] WiFi initialized");
+
+    /* Initialize SNTP */
+    if (initSntp() != ESP_OK)
+    {
+        reboot_on_error("SNTP");
+    }
+    ESP_LOGI(TAG, "[OK] SNTP initialized");
+
+    /* Initialize Control */
+    if (initControl() != ESP_OK)
+    {
+        reboot_on_error("Control");
+    }
+    ESP_LOGI(TAG, "[OK] Control initialized");
+
+    /* Initialize Metrics */
+    if (initMetrics() != ESP_OK)
+    {
+        reboot_on_error("Metrics");
+    }
+    ESP_LOGI(TAG, "[OK] Metrics initialized");
+
+    ESP_LOGI(TAG, "========================================");
+    ESP_LOGI(TAG, "All modules initialized successfully!");
+    ESP_LOGI(TAG, "System is now running.");
+    ESP_LOGI(TAG, "========================================");
 
     while (1)
     {

main/metrics.c

@@ -1,11 +1,7 @@
-#include <string.h>
+/**
-#include "esp_timer.h"
+ * @file metrics.c
-#include "freertos/FreeRTOS.h"
+ * @brief Implementation of Prometheus metrics endpoint.
-#include "freertos/task.h"
+ */
-#include "esp_wifi.h"
-#include "esp_log.h"
-#include <time.h>
-#include <sys/time.h>
 
 #include "metrics.h"
 #include "outputs.h"
@@ -14,41 +10,60 @@
 #include "sntp.h"
 #include "control.h"
 
-static const char *TAG = "smart-oil-heater-control-system-metrics";
+#include "esp_timer.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_wifi.h"
+#include "esp_log.h"
 
-char caHtmlResponse[HTML_RESPONSE_SIZE];
+#include <string.h>
-SemaphoreHandle_t xMutexAccessMetricResponse = NULL;
+#include <time.h>
+#include <sys/time.h>
+
+static const char *TAG = "metrics";
+
+static char caHtmlResponse[HTML_RESPONSE_SIZE];
+static SemaphoreHandle_t xMutexAccessMetricResponse = NULL;
 static sMetric aMetrics[METRIC_MAX_COUNT];
 static uint16_t u16MetricCounter = 0U;
 
-void taskMetrics(void *pvParameters);
+/* Private function prototypes */
-httpd_handle_t setup_server(void);
+static void taskMetrics(void *pvParameters);
-esp_err_t get_metrics_handler(httpd_req_t *req);
+static httpd_handle_t setup_server(void);
+static esp_err_t get_metrics_handler(httpd_req_t *req);
 
-void initMetrics(void)
+esp_err_t initMetrics(void)
 {
-    setup_server();
+    httpd_handle_t server = setup_server();
+    if (server == NULL)
+    {
+        ESP_LOGE(TAG, "Failed to start HTTP server");
+        return ESP_FAIL;
+    }
 
     BaseType_t taskCreated = xTaskCreate(
-        taskMetrics,   // Function to implement the task
+        taskMetrics,
-        "taskMetrics", // Task name
+        "taskMetrics",
-        32768,         // Stack size (in words, not bytes)
+        32768,
-        NULL,          // Parameters to the task function (none in this case)
+        NULL,
-        5,             // Task priority (higher number = higher priority)
+        5,
-        NULL           // Task handle (optional)
+        NULL);
-    );
 
-    if (taskCreated == pdPASS)
+    if (taskCreated != pdPASS)
-    {
-        ESP_LOGI(TAG, "Task created successfully!");
-    }
-    else
     {
         ESP_LOGE(TAG, "Failed to create task");
-    }
+        return ESP_FAIL;
     }
 
-void taskMetrics(void *pvParameters)
+    ESP_LOGI(TAG, "Initialized successfully");
+    return ESP_OK;
+}
+
+/**
+ * @brief Metrics collection task.
+ * @param pvParameters Task parameters (unused).
+ */
+static void taskMetrics(void *pvParameters)
 {
     while (1)
     {
@@ -301,23 +316,23 @@ void taskMetrics(void *pvParameters)
 
         // Wifi RSSI
         wifi_ap_record_t ap;
-        esp_wifi_sta_get_ap_info(&ap);
+        ap.rssi = 0U;
+        ESP_ERROR_CHECK(esp_wifi_sta_get_ap_info(&ap));
         strcpy(aMetrics[u16MetricCounter].caMetricName, "wifi_rssi");
         aMetrics[u16MetricCounter].type = INTEGER_64;
         aMetrics[u16MetricCounter].i64MetricValue = ap.rssi;
         u16MetricCounter++;
 
-        ESP_ERROR_CHECK(u16MetricCounter > METRIC_MAX_COUNT);
+        configASSERT(!(u16MetricCounter > METRIC_MAX_COUNT));
         vSetMetrics(aMetrics, u16MetricCounter);
     }
 }
 
 void vSetMetrics(sMetric *paMetrics, uint16_t u16Size)
 {
-
     if (xSemaphoreTakeRecursive(xMutexAccessMetricResponse, pdMS_TO_TICKS(5000)) == pdTRUE)
     {
-        memset(caHtmlResponse, 0U, strlen(caHtmlResponse));
+        memset(caHtmlResponse, 0U, HTML_RESPONSE_SIZE);
         for (uint16_t u16Index = 0U; u16Index < u16Size; u16Index++)
         {
             char caValueBuffer[64];
@@ -337,8 +352,6 @@ void vSetMetrics(sMetric *paMetrics, uint16_t u16Size)
                 break;
             }
 
-            // printf("%s\n", paMetrics[u16Index].caMetricName);
-            // printf("%s\n", caValueBuffer);
             strcat(caHtmlResponse, paMetrics[u16Index].caMetricName);
             strcat(caHtmlResponse, caValueBuffer);
             strcat(caHtmlResponse, "\n");
@@ -351,7 +364,12 @@ void vSetMetrics(sMetric *paMetrics, uint16_t u16Size)
     }
 }
 
-esp_err_t get_metrics_handler(httpd_req_t *req)
+/**
+ * @brief HTTP GET handler for /metrics endpoint.
+ * @param req HTTP request.
+ * @return ESP_OK on success.
+ */
+static esp_err_t get_metrics_handler(httpd_req_t *req)
 {
     if (xSemaphoreTakeRecursive(xMutexAccessMetricResponse, pdMS_TO_TICKS(5000)) == pdTRUE)
     {
@@ -366,7 +384,11 @@ esp_err_t get_metrics_handler(httpd_req_t *req)
     }
 }
 
-httpd_handle_t setup_server(void)
+/**
+ * @brief Setup HTTP server for metrics endpoint.
+ * @return HTTP server handle or NULL on failure.
+ */
+static httpd_handle_t setup_server(void)
 {
     httpd_config_t config = HTTPD_DEFAULT_CONFIG();
     config.server_port = 9100;
@@ -381,14 +403,17 @@ httpd_handle_t setup_server(void)
     xMutexAccessMetricResponse = xSemaphoreCreateRecursiveMutex();
     if (xMutexAccessMetricResponse == NULL)
     {
-        ESP_LOGE(TAG, "Unable to create mutex for metric response");
+        ESP_LOGE(TAG, "Failed to create mutex");
+        return NULL;
     }
     xSemaphoreGiveRecursive(xMutexAccessMetricResponse);
 
     if (httpd_start(&server, &config) == ESP_OK)
     {
         httpd_register_uri_handler(server, &uri_get);
-    }
-
         return server;
     }
+
+    ESP_LOGE(TAG, "Failed to start HTTP server");
+    return NULL;
+}

main/metrics.h

@@ -1,26 +1,61 @@
+/**
+ * @file metrics.h
+ * @brief Prometheus metrics HTTP endpoint.
+ *
+ * This module provides a HTTP server on port 9100 that exposes
+ * system metrics in Prometheus format at /metrics endpoint.
+ */
+
 #pragma once
 
-#include <esp_http_server.h>
+#include "esp_err.h"
+#include "esp_http_server.h"
 
+#include <stdint.h>
+
+/** @brief Maximum size of HTTP response buffer. */
 #define HTML_RESPONSE_SIZE 4096U
+
+/** @brief Maximum length of metric name. */
 #define METRIC_NAME_MAX_SIZE 64U
+
+/** @brief Maximum number of metrics. */
 #define METRIC_MAX_COUNT 38U
 
+/**
+ * @brief Metric value type enumeration.
+ */
 typedef enum _MetricValueType
 {
-    FLOAT,
+    FLOAT,      /**< Floating point value. */
-    INTEGER_U8,
+    INTEGER_U8, /**< 8-bit unsigned integer. */
-    INTEGER_64,
+    INTEGER_64, /**< 64-bit signed integer. */
 } eMetricValueType;
 
+/**
+ * @brief Metric data structure.
+ */
 typedef struct _metric
 {
-    char caMetricName[METRIC_NAME_MAX_SIZE];
+    char caMetricName[METRIC_NAME_MAX_SIZE]; /**< Metric name. */
-    eMetricValueType type;
+    eMetricValueType type;                   /**< Value type. */
-    float fMetricValue;
+    float fMetricValue;                      /**< Float value (if type is FLOAT). */
-    uint8_t u8MetricValue;
+    uint8_t u8MetricValue;                   /**< U8 value (if type is INTEGER_U8). */
-    int64_t i64MetricValue;
+    int64_t i64MetricValue;                  /**< I64 value (if type is INTEGER_64). */
 } sMetric;
 
-void initMetrics(void);
+/**
+ * @brief Initialize the metrics module.
+ *
+ * Starts the HTTP server and creates the metrics collection task.
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initMetrics(void);
+
+/**
+ * @brief Update the metrics buffer.
+ * @param paMetrics Array of metrics to publish.
+ * @param u16Size Number of metrics in array.
+ */
 void vSetMetrics(sMetric *paMetrics, uint16_t u16Size);

main/outputs.c

@@ -1,61 +1,101 @@
+/**
+ * @file outputs.c
+ * @brief Implementation of output control module.
+ */
+
+#include "outputs.h"
+
+#include "sdkconfig.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "driver/gpio.h"
 #include "esp_log.h"
 
-#include "outputs.h"
+static const char *TAG = "outputs";
 
-static const char *TAG = "smart-oil-heater-control-system-outputs";
+/** @brief Circulation pump GPIO pin (from Kconfig). */
-const uint8_t uCirculationPumpGpioPin = 27U;
+static const uint8_t uCirculationPumpGpioPin = CONFIG_GPIO_CIRCULATION_PUMP;
-const uint8_t uBurnerGpioPin = 14U;
+
-const uint8_t uSafetyContactGpioPin = 12U;
+/** @brief Burner control GPIO pin (from Kconfig). */
+static const uint8_t uBurnerGpioPin = CONFIG_GPIO_BURNER;
+
+/** @brief Safety contact GPIO pin (from Kconfig). */
+static const uint8_t uSafetyContactGpioPin = CONFIG_GPIO_SAFETY_CONTACT;
 
 static SemaphoreHandle_t xMutexAccessOutputs = NULL;
 static eOutput sCirculationPumpState;
 static eOutput sBurnerState;
 static eOutput sSafetyContactState;
 
-void initOutputs(void)
+esp_err_t initOutputs(void)
 {
     gpio_config_t ioConfCirculationPump = {
-        .pin_bit_mask = (1ULL << uCirculationPumpGpioPin), // Pin mask
+        .pin_bit_mask = (1ULL << uCirculationPumpGpioPin),
-        .mode = GPIO_MODE_OUTPUT,                          // Set as output
+        .mode = GPIO_MODE_OUTPUT,
-        .pull_up_en = GPIO_PULLUP_DISABLE,                 // Disable pull-up
+        .pull_up_en = GPIO_PULLUP_DISABLE,
-        .pull_down_en = GPIO_PULLDOWN_DISABLE,             // Disable pull-down
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
-        .intr_type = GPIO_INTR_DISABLE                     // Disable interrupts
+        .intr_type = GPIO_INTR_DISABLE};
-    };
 
     gpio_config_t ioConfBurner = {
-        .pin_bit_mask = (1ULL << uBurnerGpioPin), // Pin mask
+        .pin_bit_mask = (1ULL << uBurnerGpioPin),
-        .mode = GPIO_MODE_OUTPUT,                 // Set as output
+        .mode = GPIO_MODE_OUTPUT,
-        .pull_up_en = GPIO_PULLUP_DISABLE,        // Disable pull-up
+        .pull_up_en = GPIO_PULLUP_DISABLE,
-        .pull_down_en = GPIO_PULLDOWN_DISABLE,    // Disable pull-down
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
-        .intr_type = GPIO_INTR_DISABLE            // Disable interrupts
+        .intr_type = GPIO_INTR_DISABLE};
-    };
 
     gpio_config_t ioConfSafetyContact = {
-        .pin_bit_mask = (1ULL << uSafetyContactGpioPin), // Pin mask
+        .pin_bit_mask = (1ULL << uSafetyContactGpioPin),
-        .mode = GPIO_MODE_OUTPUT,                        // Set as output
+        .mode = GPIO_MODE_OUTPUT,
-        .pull_up_en = GPIO_PULLUP_DISABLE,               // Disable pull-up
+        .pull_up_en = GPIO_PULLUP_DISABLE,
-        .pull_down_en = GPIO_PULLDOWN_DISABLE,           // Disable pull-down
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
-        .intr_type = GPIO_INTR_DISABLE                   // Disable interrupts
+        .intr_type = GPIO_INTR_DISABLE};
-    };
 
-    gpio_config(&ioConfCirculationPump);
+    esp_err_t ret = gpio_config(&ioConfCirculationPump);
-    gpio_config(&ioConfBurner);
+    if (ret != ESP_OK)
-    gpio_config(&ioConfSafetyContact);
+    {
+        ESP_LOGE(TAG, "GPIO config failed for circulation pump: %s", esp_err_to_name(ret));
+        return ESP_FAIL;
+    }
+
+    ret = gpio_config(&ioConfBurner);
+    if (ret != ESP_OK)
+    {
+        ESP_LOGE(TAG, "GPIO config failed for burner: %s", esp_err_to_name(ret));
+        return ESP_FAIL;
+    }
+
+    ret = gpio_config(&ioConfSafetyContact);
+    if (ret != ESP_OK)
+    {
+        ESP_LOGE(TAG, "GPIO config failed for safety contact: %s", esp_err_to_name(ret));
+        return ESP_FAIL;
+    }
 
     xMutexAccessOutputs = xSemaphoreCreateRecursiveMutex();
     if (xMutexAccessOutputs == NULL)
     {
-        ESP_LOGE(TAG, "Unable to create mutex");
+        ESP_LOGE(TAG, "Failed to create mutex");
+        return ESP_FAIL;
     }
     xSemaphoreGiveRecursive(xMutexAccessOutputs);
+
+    ESP_LOGI(TAG, "Initialized successfully");
+    return ESP_OK;
 }
 
 eOutput getCirculationPumpState(void)
 {
-    return sCirculationPumpState;
+    eOutput ret = ENABLED;
+    if (xSemaphoreTakeRecursive(xMutexAccessOutputs, pdMS_TO_TICKS(5000)) == pdTRUE)
+    {
+        ret = sCirculationPumpState;
+        xSemaphoreGiveRecursive(xMutexAccessOutputs);
+    }
+    else
+    {
+        ESP_LOGE(TAG, "Unable to take mutex: getCirculationPumpState()");
+    }
+    return ret;
 }
 
 void setCirculationPumpState(eOutput in)
@@ -70,6 +110,7 @@ void setCirculationPumpState(eOutput in)
             break;
         case DISABLED:
             gpio_set_level(uCirculationPumpGpioPin, 1U); // Switch off Circulation Pump
+            break;
         default:
             break;
         }
@@ -108,6 +149,7 @@ void setBurnerState(eOutput in)
             break;
         case DISABLED:
             gpio_set_level(uBurnerGpioPin, 1U); // Switch off Burner
+            break;
         default:
             break;
         }
@@ -146,6 +188,7 @@ void setSafetyControlState(eOutput in)
             break;
         case DISABLED:
             gpio_set_level(uSafetyContactGpioPin, 1U); // Switch off power for Burner
+            break;
         default:
             break;
         }

main/outputs.h

@@ -1,15 +1,70 @@
+/**
+ * @file outputs.h
+ * @brief Output control for circulation pump, burner, and safety contact.
+ *
+ * This module controls the relay outputs via GPIO pins. All outputs
+ * are active-low (relay energized when GPIO is low).
+ */
+
 #pragma once
 
+#include "esp_err.h"
+
+/**
+ * @brief Output state enumeration.
+ */
 typedef enum _Output
 {
-    ENABLED,
+    ENABLED, /**< Output active (relay energized, GPIO low). */
-    DISABLED
+    DISABLED /**< Output inactive (relay de-energized, GPIO high). */
 } eOutput;
 
-void initOutputs(void);
+/**
+ * @brief Initialize the outputs module.
+ *
+ * Configures GPIO pins for circulation pump, burner, and safety contact
+ * as outputs. All outputs are initialized to DISABLED (safe state).
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initOutputs(void);
+
+/**
+ * @brief Get the current circulation pump state.
+ * @return eOutput state (ENABLED or DISABLED).
+ */
 eOutput getCirculationPumpState(void);
+
+/**
+ * @brief Set the circulation pump state.
+ * @param in Desired state (ENABLED or DISABLED).
+ */
 void setCirculationPumpState(eOutput in);
+
+/**
+ * @brief Get the current burner state.
+ * @return eOutput state (ENABLED or DISABLED).
+ */
 eOutput getBurnerState(void);
+
+/**
+ * @brief Set the burner state.
+ * @param in Desired state (ENABLED or DISABLED).
+ */
 void setBurnerState(eOutput in);
+
+/**
+ * @brief Get the current safety contact state.
+ * @return eOutput state (ENABLED or DISABLED).
+ */
 eOutput getSafetyControlState(void);
+
+/**
+ * @brief Set the safety contact state.
+ *
+ * The safety contact controls power to the burner. When DISABLED,
+ * the burner cannot operate regardless of the burner signal.
+ *
+ * @param in Desired state (ENABLED or DISABLED).
+ */
 void setSafetyControlState(eOutput in);

main/safety.c

@@ -1,56 +1,79 @@
+/**
+ * @file safety.c
+ * @brief Implementation of safety monitoring module.
+ */
+
+#include "safety.h"
+
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "esp_log.h"
+
 #include <string.h>
-#include "safety.h"
+#include <math.h>
 
-#define PERIODIC_INTERVAL 1U            // run safety checks every 1sec
+/** @brief Task interval in seconds. */
-#define SENSOR_GRACE_PERIOD (60U * 30U) // period that a sensor can report the same reading in seconds
+#define PERIODIC_INTERVAL 1U
+
+/** @brief Grace period for unchanged sensor readings (seconds). */
+#define SENSOR_GRACE_PERIOD (CONFIG_SENSOR_GRACE_PERIOD_MINUTES * 60U)
+
+/** @brief Epsilon for float comparison. */
+#define FLOAT_EPSILON 0.0001f
+
+static const char *TAG = "safety";
 
-static const char *TAG = "smart-oil-heater-control-system-safety";
 static SemaphoreHandle_t xMutexAccessSafety = NULL;
+
+/** @brief Sensor sanity check configurations. */
 static sSensorSanityCheck sanityChecks[NUMBER_OF_SENSOR_SANITY_CHECKS] = {
-    {SENSOR_NO_ERROR, "chamber_temperature", {95.0f, -10.0f}, 0.0f, 0U, getChamberTemperature},
+    {SENSOR_NO_ERROR, "chamber_temperature", {SENSOR_LIMIT_CHAMBER_MAX, SENSOR_LIMIT_CHAMBER_MIN}, 0.0f, 0U, getChamberTemperature},
-    {SENSOR_NO_ERROR, "outdoor_temperature", {45.0f, -20.0f}, 0.0f, 0U, getOutdoorTemperature},
+    {SENSOR_NO_ERROR, "outdoor_temperature", {SENSOR_LIMIT_OUTDOOR_MAX, SENSOR_LIMIT_OUTDOOR_MIN}, 0.0f, 0U, getOutdoorTemperature},
-    {SENSOR_NO_ERROR, "inlet_flow_temperature", {95.0f, -10.0f}, 0.0f, 0U, getInletFlowTemperature},
+    {SENSOR_NO_ERROR, "inlet_flow_temperature", {SENSOR_LIMIT_INLET_MAX, SENSOR_LIMIT_INLET_MIN}, 0.0f, 0U, getInletFlowTemperature},
-    {SENSOR_NO_ERROR, "return_flow_temperature", {95.0f, -10.0f}, 0.0f, 0U, getReturnFlowTemperature}};
+    {SENSOR_NO_ERROR, "return_flow_temperature", {SENSOR_LIMIT_RETURN_MAX, SENSOR_LIMIT_RETURN_MIN}, 0.0f, 0U, getReturnFlowTemperature}};
+
 static eSafetyState sSafetyState = SAFETY_NO_ERROR;
 
-void taskSafety(void *pvParameters);
+/* Private function prototypes */
-void checkSensorSanity(void);
+static void taskSafety(void *pvParameters);
-void setSafeState(void);
+static void checkSensorSanity(void);
+static void setSafeState(void);
 
-void initSafety(void)
+esp_err_t initSafety(void)
 {
     xMutexAccessSafety = xSemaphoreCreateRecursiveMutex();
     if (xMutexAccessSafety == NULL)
     {
-        ESP_LOGE(TAG, "Unable to create mutex");
+        ESP_LOGE(TAG, "Failed to create mutex");
+        return ESP_FAIL;
     }
     xSemaphoreGiveRecursive(xMutexAccessSafety);
 
     BaseType_t taskCreated = xTaskCreate(
-        taskSafety,   // Function to implement the task
+        taskSafety,
-        "taskSafety", // Task name
+        "taskSafety",
-        4096,         // Stack size (in words, not bytes)
+        4096,
-        NULL,         // Parameters to the task function (none in this case)
+        NULL,
-        5,            // Task priority (higher number = higher priority)
+        5,
-        NULL          // Task handle (optional)
+        NULL);
-    );
 
-    if (taskCreated == pdPASS)
+    if (taskCreated != pdPASS)
-    {
-        ESP_LOGI(TAG, "Task created successfully!");
-    }
-    else
     {
         ESP_LOGE(TAG, "Failed to create task");
+        return ESP_FAIL;
     }
 
-    setSafeState(); // Set inital state
+    setSafeState();
+
+    ESP_LOGI(TAG, "Initialized successfully");
+    return ESP_OK;
 }
 
-void taskSafety(void *pvParameters)
+/**
+ * @brief Safety monitoring task.
+ * @param pvParameters Task parameters (unused).
+ */
+static void taskSafety(void *pvParameters)
 {
     while (1)
     {
@@ -58,7 +81,6 @@ void taskSafety(void *pvParameters)
 
         if (xSemaphoreTakeRecursive(xMutexAccessSafety, portMAX_DELAY) == pdTRUE)
         {
-
             checkSensorSanity();
 
             if (sSafetyState != SAFETY_NO_ERROR)
@@ -71,7 +93,10 @@ void taskSafety(void *pvParameters)
     }
 }
 
-void checkSensorSanity(void)
+/**
+ * @brief Check all sensor readings for sanity.
+ */
+static void checkSensorSanity(void)
 {
     sSafetyState = SAFETY_NO_ERROR;
     for (int i = 0; i < NUMBER_OF_SENSOR_SANITY_CHECKS; i++)
@@ -91,7 +116,7 @@ void checkSensorSanity(void)
         }
         else
         {
-            if (sCurrentMeasurement.fCurrentValue == sanityChecks[i].fSensorTemperatureLast)
+            if (fabsf(sCurrentMeasurement.fCurrentValue - sanityChecks[i].fSensorTemperatureLast) < FLOAT_EPSILON)
             {
                 sanityChecks[i].uUnchangedCounter++;
                 if (sanityChecks[i].uUnchangedCounter >= (SENSOR_GRACE_PERIOD / PERIODIC_INTERVAL))
@@ -103,6 +128,7 @@ void checkSensorSanity(void)
             }
             else
             {
+                sanityChecks[i].uUnchangedCounter = 0U;
                 sanityChecks[i].fSensorTemperatureLast = sCurrentMeasurement.fCurrentValue;
 
                 if (sCurrentMeasurement.fCurrentValue > sanityChecks[i].sSensorLimit.max)
@@ -119,16 +145,17 @@ void checkSensorSanity(void)
                 }
                 else
                 {
-                    sanityChecks[i].uUnchangedCounter = 0U;
                     sanityChecks[i].state = SENSOR_NO_ERROR;
                 }
             }
         }
-        // printf("  state: %u\n", sanityChecks[i].state);
     }
 }
 
-void setSafeState(void)
+/**
+ * @brief Set system to safe state (burner off, pump on).
+ */
+static void setSafeState(void)
 {
     setCirculationPumpState(ENABLED); // To cool down system
     setBurnerState(DISABLED);         // Deactivate burner
@@ -143,7 +170,7 @@ void getSensorSanityStates(sSensorSanityCheck *pSensorSanityChecks)
         {
             // Copy only the needed attributes
             pSensorSanityChecks[i].state = sanityChecks[i].state;
-            strcpy(pSensorSanityChecks[i].name, sanityChecks[i].name);
+            strncpy(pSensorSanityChecks[i].name, sanityChecks[i].name, MAX_ERROR_STRING_SIZE);
         }
         xSemaphoreGiveRecursive(xMutexAccessSafety);
     }

main/safety.h

@@ -1,43 +1,117 @@
+/**
+ * @file safety.h
+ * @brief Safety monitoring for temperature sensors.
+ *
+ * This module performs sanity checks on all temperature sensors and
+ * puts the system into a safe state if any sensor fails.
+ */
+
 #pragma once
 
 #include "outputs.h"
 #include "inputs.h"
 
+#include "sdkconfig.h"
+#include "esp_err.h"
+
+#include <stdint.h>
+
+/** @brief Maximum length of sensor name string. */
 #define MAX_ERROR_STRING_SIZE 64U
+
+/** @brief Number of sensors to monitor. */
 #define NUMBER_OF_SENSOR_SANITY_CHECKS 4U
 
+/** @brief Chamber sensor maximum temperature limit (°C). */
+#define SENSOR_LIMIT_CHAMBER_MAX (CONFIG_SENSOR_LIMIT_CHAMBER_MAX / 10.0f)
+
+/** @brief Chamber sensor minimum temperature limit (°C). */
+#define SENSOR_LIMIT_CHAMBER_MIN (CONFIG_SENSOR_LIMIT_CHAMBER_MIN / 10.0f)
+
+/** @brief Outdoor sensor maximum temperature limit (°C). */
+#define SENSOR_LIMIT_OUTDOOR_MAX (CONFIG_SENSOR_LIMIT_OUTDOOR_MAX / 10.0f)
+
+/** @brief Outdoor sensor minimum temperature limit (°C). */
+#define SENSOR_LIMIT_OUTDOOR_MIN (CONFIG_SENSOR_LIMIT_OUTDOOR_MIN / 10.0f)
+
+/** @brief Inlet flow sensor maximum temperature limit (°C). */
+#define SENSOR_LIMIT_INLET_MAX (CONFIG_SENSOR_LIMIT_INLET_MAX / 10.0f)
+
+/** @brief Inlet flow sensor minimum temperature limit (°C). */
+#define SENSOR_LIMIT_INLET_MIN (CONFIG_SENSOR_LIMIT_INLET_MIN / 10.0f)
+
+/** @brief Return flow sensor maximum temperature limit (°C). */
+#define SENSOR_LIMIT_RETURN_MAX (CONFIG_SENSOR_LIMIT_RETURN_MAX / 10.0f)
+
+/** @brief Return flow sensor minimum temperature limit (°C). */
+#define SENSOR_LIMIT_RETURN_MIN (CONFIG_SENSOR_LIMIT_RETURN_MIN / 10.0f)
+
+/**
+ * @brief Sensor error state enumeration.
+ */
 typedef enum _SensorErrorState
 {
-    SENSOR_NO_ERROR,
+    SENSOR_NO_ERROR,  /**< Sensor operating normally. */
-    SENSOR_TOO_HIGH,
+    SENSOR_TOO_HIGH,  /**< Temperature above maximum limit. */
-    SENSOR_TOO_LOW,
+    SENSOR_TOO_LOW,   /**< Temperature below minimum limit. */
-    SENSOR_UNCHANGED,
+    SENSOR_UNCHANGED, /**< Temperature unchanged for too long. */
-    SENSOR_NOT_FOUND
+    SENSOR_NOT_FOUND  /**< Sensor not responding. */
 } eSensorErrorState;
 
+/**
+ * @brief Overall safety state enumeration.
+ */
 typedef enum _SafetyState
 {
-    SAFETY_NO_ERROR,
+    SAFETY_NO_ERROR,      /**< All sensors OK. */
-    SAFETY_SENSOR_ERROR,
+    SAFETY_SENSOR_ERROR,  /**< At least one sensor failed. */
-    SAFETY_INTERNAL_ERROR
+    SAFETY_INTERNAL_ERROR /**< Internal module error. */
 } eSafetyState;
 
+/**
+ * @brief Function pointer type for sensor getter functions.
+ */
 typedef sMeasurement (*GetSensorValue)();
+
+/**
+ * @brief Temperature sensor limits.
+ */
 typedef struct _TemperatureSensorLimit
 {
-    float max; // Maximum temperature limit
+    float max; /**< Maximum temperature limit. */
-    float min; // Minimum temperature limit
+    float min; /**< Minimum temperature limit. */
 } sTemperatureSensorLimit;
+
+/**
+ * @brief Sensor sanity check state structure.
+ */
 typedef struct _SensorSanityCheck
 {
-    eSensorErrorState state;
+    eSensorErrorState state;              /**< Current error state. */
-    char name[MAX_ERROR_STRING_SIZE];
+    char name[MAX_ERROR_STRING_SIZE];     /**< Sensor name for logging. */
-    sTemperatureSensorLimit sSensorLimit;
+    sTemperatureSensorLimit sSensorLimit; /**< Temperature limits. */
-    float fSensorTemperatureLast;
+    float fSensorTemperatureLast;         /**< Last temperature reading. */
-    uint32_t uUnchangedCounter;
+    uint32_t uUnchangedCounter;           /**< Counter for unchanged readings. */
-    GetSensorValue getSensor;
+    GetSensorValue getSensor;             /**< Function to get sensor value. */
 } sSensorSanityCheck;
 
-void initSafety(void);
+/**
+ * @brief Initialize the safety module.
+ *
+ * Creates the safety monitoring task and sets initial safe state.
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initSafety(void);
+
+/**
+ * @brief Get the current sensor sanity states.
+ * @param[out] pSensorSanityChecks Array to receive sensor states.
+ */
 void getSensorSanityStates(sSensorSanityCheck *pSensorSanityChecks);
+
+/**
+ * @brief Get the overall safety state.
+ * @return eSafetyState indicating current safety status.
+ */
 eSafetyState getSafetyState(void);

main/sntp.c

@@ -1,21 +1,32 @@
-#include <time.h>
+/**
-#include <sys/time.h>
+ * @file sntp.c
-#include <esp_sntp.h>
+ * @brief Implementation of SNTP client module.
-#include "esp_log.h"
+ */
 
 #include "sntp.h"
 
-static const char *TAG = "smart-oil-heater-control-system-sntp";
+#include "esp_sntp.h"
-static eSntpState sntpState = SYNC_NOT_STARTED;
+#include "esp_log.h"
-void time_sync_notification_cb(struct timeval *tv);
 
-void initSntp(void)
+#include <time.h>
+#include <sys/time.h>
+
+static const char *TAG = "sntp";
+
+static volatile eSntpState sntpState = SYNC_NOT_STARTED;
+
+static void time_sync_notification_cb(struct timeval *tv);
+
+esp_err_t initSntp(void)
 {
     esp_sntp_setoperatingmode(SNTP_OPMODE_POLL);
     esp_sntp_setservername(0, CONFIG_SNTP_SERVER_IP_ADDR);
 
     sntp_set_time_sync_notification_cb(time_sync_notification_cb);
     esp_sntp_init();
+
+    ESP_LOGI(TAG, "Initialized successfully, server: %s", CONFIG_SNTP_SERVER_IP_ADDR);
+    return ESP_OK;
 }
 
 eSntpState getSntpState(void)
@@ -23,8 +34,12 @@ eSntpState getSntpState(void)
     return sntpState;
 }
 
-void time_sync_notification_cb(struct timeval *tv)
+/**
+ * @brief SNTP time sync callback.
+ * @param tv Synchronized time value.
+ */
+static void time_sync_notification_cb(struct timeval *tv)
 {
-    ESP_LOGI(TAG, "SNTP synchronization! Unix Time: %lld", tv->tv_sec);
+    ESP_LOGI(TAG, "Time synchronized! Unix Time: %lld", tv->tv_sec);
     sntpState = SYNC_SUCCESSFUL;
 }

main/sntp.h

@@ -1,11 +1,37 @@
+/**
+ * @file sntp.h
+ * @brief SNTP client for time synchronization.
+ *
+ * This module synchronizes system time with an NTP server.
+ * Time sync is required for schedule-based heating control.
+ */
+
 #pragma once
 
+#include "esp_err.h"
+
+/**
+ * @brief SNTP synchronization state enumeration.
+ */
 typedef enum _SntpState
 {
-    SYNC_SUCCESSFUL,
+    SYNC_SUCCESSFUL,  /**< Time synchronized successfully. */
-    SYNC_NOT_STARTED,
+    SYNC_NOT_STARTED, /**< Synchronization not yet attempted. */
-    SYNC_FAILED,
+    SYNC_FAILED,      /**< Synchronization failed. */
 } eSntpState;
 
-void initSntp(void);
+/**
+ * @brief Initialize the SNTP client.
+ *
+ * Configures SNTP with the server from Kconfig and starts
+ * periodic time synchronization.
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initSntp(void);
+
+/**
+ * @brief Get the current SNTP synchronization state.
+ * @return eSntpState indicating sync status.
+ */
 eSntpState getSntpState(void);

main/wifi.c

@@ -1,22 +1,35 @@
-#include <string.h>
+/**
+ * @file wifi.c
+ * @brief Implementation of WiFi station mode module.
+ */
+
+#include "wifi.h"
+
 #include "esp_timer.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include "freertos/event_groups.h"
 #include "esp_wifi.h"
 #include "esp_event.h"
-#include "freertos/event_groups.h"
 #include "esp_log.h"
 #include "esp_netif.h"
 #include <lwip/sockets.h>
 
-#include "wifi.h"
+#include <string.h>
 
+/** @brief Event bit for successful connection. */
 #define WIFI_CONNECTED_BIT BIT0
+
+/** @brief Event bit for connection failure. */
 #define WIFI_FAIL_BIT BIT1
+
+/** @brief Maximum connection retry attempts. */
 #define MAX_RETRY_COUNT 10
+
+/** @brief Delay between retries in milliseconds. */
 #define RETRY_DELAY_MS 1000
 
-static const char *TAG = "smart-oil-heater-control-system-wifi";
+static const char *TAG = "wifi";
 
 static EventGroupHandle_t s_wifi_event_group;
 static int s_retry_num = 0;
@@ -25,19 +38,25 @@ static bool s_initial_connect = true;
 static void event_handler(void *arg, esp_event_base_t event_base,
                           int32_t event_id, void *event_data);
 
-void initWifi(void)
+esp_err_t initWifi(void)
 {
     s_wifi_event_group = xEventGroupCreate();
+    if (s_wifi_event_group == NULL)
+    {
+        ESP_LOGE(TAG, "Failed to create event group");
+        return ESP_FAIL;
+    }
+
     ESP_ERROR_CHECK(esp_netif_init());
     ESP_ERROR_CHECK(esp_event_loop_create_default());
 
     esp_netif_t *my_sta = esp_netif_create_default_wifi_sta();
-    esp_netif_dhcpc_stop(my_sta);
+    ESP_ERROR_CHECK(esp_netif_dhcpc_stop(my_sta));
     esp_netif_ip_info_t ip_info;
     ip_info.ip.addr = ipaddr_addr(CONFIG_STATIC_IP_ADDR);
     ip_info.gw.addr = ipaddr_addr(CONFIG_STATIC_GATEWAY_IP_ADDR);
     ip_info.netmask.addr = ipaddr_addr(CONFIG_STATIC_IP_NETMASK);
-    esp_netif_set_ip_info(my_sta, &ip_info);
+    ESP_ERROR_CHECK(esp_netif_set_ip_info(my_sta, &ip_info));
 
     wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
     ESP_ERROR_CHECK(esp_wifi_init(&cfg));
@@ -66,10 +85,10 @@ void initWifi(void)
 
     ESP_ERROR_CHECK(esp_wifi_start());
 
-    ESP_ERROR_CHECK(esp_wifi_set_max_tx_power(78));      // Set max power to 19.5 dBm (78 in units of 0.25 dBm)
+    ESP_ERROR_CHECK(esp_wifi_set_max_tx_power(78));
-    ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_MIN_MODEM)); // Use power-saving mode
+    ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_MIN_MODEM));
 
-    ESP_LOGI(TAG, "wifi_init_sta finished.");
+    ESP_LOGI(TAG, "WiFi init finished, waiting for connection...");
 
     EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,
                                            WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
@@ -79,21 +98,32 @@ void initWifi(void)
 
     if (bits & WIFI_CONNECTED_BIT)
     {
-        ESP_LOGI(TAG, "Connected to ap SSID:%s", CONFIG_SSID);
+        ESP_LOGI(TAG, "Connected to AP SSID:%s", CONFIG_SSID);
     }
     else if (bits & WIFI_FAIL_BIT)
     {
-        ESP_LOGI(TAG, "Failed to connect to SSID:%s", CONFIG_SSID);
+        ESP_LOGE(TAG, "Failed to connect to SSID:%s", CONFIG_SSID);
+        return ESP_FAIL;
     }
     else
     {
         ESP_LOGE(TAG, "Unexpected event");
+        return ESP_FAIL;
     }
 
-    // Mark initial connection phase complete - do NOT delete the event group
     s_initial_connect = false;
+
+    ESP_LOGI(TAG, "Initialized successfully");
+    return ESP_OK;
 }
 
+/**
+ * @brief WiFi event handler.
+ * @param arg User argument (unused).
+ * @param event_base Event base.
+ * @param event_id Event ID.
+ * @param event_data Event data.
+ */
 static void event_handler(void *arg, esp_event_base_t event_base,
                           int32_t event_id, void *event_data)
 {

main/wifi.h

@@ -1,3 +1,22 @@
+/**
+ * @file wifi.h
+ * @brief WiFi station mode initialization and management.
+ *
+ * This module initializes WiFi in station mode with static IP
+ * configuration. It handles connection and automatic reconnection.
+ */
+
 #pragma once
 
-void initWifi(void);
+#include "esp_err.h"
+
+/**
+ * @brief Initialize WiFi in station mode.
+ *
+ * Configures WiFi with static IP address from Kconfig settings
+ * and connects to the configured access point. Blocks until
+ * connected or maximum retry count is reached.
+ *
+ * @return ESP_OK on success, ESP_FAIL on error.
+ */
+esp_err_t initWifi(void);