Potential division by zero

main/control.c

@@ -25,9 +25,9 @@
     (60U * 4U) // Burner fault detection after 4 minutes
 
 static const char *TAG = "smart-oil-heater-control-system-control";
-static eControlState sControlState = CONTROL_STARTING;
+static eControlState gControlState = CONTROL_STARTING;
 // Control table for daily schedules
-static const sControlDay aControlTable[] = {
+static const sControlDay gControlTable[] = {
     {MONDAY,
      2U,
      {{{4, 45},
@@ -85,15 +85,25 @@ static const sControlDay aControlTable[] = {
        RETURN_FLOW_TEMPERATURE_LOWER_LIMIT_NIGHT,
        CHAMBER_TEMPERATURE_TARGET}}},
 };
-static sControlTemperatureEntry currentControlEntry =
+static sControlTemperatureEntry gCurrentControlEntry =
-    aControlTable[0].aTemperatureEntries[0];
+    gControlTable[0].aTemperatureEntries[0];
+static SemaphoreHandle_t xMutexAccessControl = NULL;
 
 // Function prototypes
 void taskControl(void *pvParameters);
 void findControlCurrentTemperatureEntry(void);
+void setControlState(eControlState state);
 
 void initControl(void)
 {
+
+    xMutexAccessControl = xSemaphoreCreateRecursiveMutex();
+    if (xMutexAccessControl == NULL)
+    {
+        ESP_LOGE(TAG, "Unable to create mutex");
+    }
+    xSemaphoreGiveRecursive(xMutexAccessControl);
+
     BaseType_t taskCreated =
         xTaskCreate(taskControl,   // Function to implement the task
                     "taskControl", // Task name
@@ -117,7 +127,7 @@ 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)
@@ -128,7 +138,7 @@ void taskControl(void *pvParameters)
         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");
@@ -143,7 +153,7 @@ void taskControl(void *pvParameters)
         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");
@@ -155,8 +165,6 @@ void taskControl(void *pvParameters)
         }
 
         findControlCurrentTemperatureEntry();
-        sControlTemperatureEntry currentControlEntry =
-            getControlCurrentTemperatureEntry();
 
         if (getOutdoorTemperature().fDampedValue >=
             SUMMER_MODE_TEMPERATURE_THRESHOLD_HIGH)
@@ -171,33 +179,33 @@ void taskControl(void *pvParameters)
 
         // Enable burner if outdoor temperature is low and return flow temperature
         // is cooled down
-        if (!bHeatingInAction && (eBurnerState != BURNER_FAULT))
+        if (!bHeatingInAction && (burnerState != 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 <=
                       CHAMBER_TEMPERATURE_THRESHOLD))
             {
                 ESP_LOGI(TAG,
                          "Enabling burner: Return flow temperature target reached");
-                eBurnerState = BURNER_UNKNOWN;
+                burnerState = 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");
-                sControlState = CONTROL_RETURN_FLOW_TOO_WARM;
+                setControlState(CONTROL_RETURN_FLOW_TOO_WARM);
             }
         }
 
@@ -205,9 +213,9 @@ void taskControl(void *pvParameters)
         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 +225,14 @@ 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);
                     }
@@ -232,7 +240,7 @@ void taskControl(void *pvParameters)
                     {
                         // ESP_LOGI(TAG, "No burner fault detected: Marking burner as
                         // fired");
-                        eBurnerState = BURNER_FIRED;
+                        burnerState = BURNER_FIRED;
                     }
                 }
             }
@@ -253,17 +261,47 @@ void taskControl(void *pvParameters)
     } // End of while(1)
 }
 
-eControlState getControlState(void) { return sControlState; }
+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)
 {
+    // Get current time
     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);
 }
 
@@ -294,66 +332,87 @@ void findControlCurrentTemperatureEntry(void)
     int currentHour = timeinfo.tm_hour;
     int currentMinute = timeinfo.tm_min;
 
-    // ESP_LOGI(TAG, "Searching for control entry - Day: %d, Time: %02d:%02d", currentDay, currentHour, currentMinute);
+    if (xSemaphoreTakeRecursive(xMutexAccessControl, pdMS_TO_TICKS(5000)) == pdTRUE)
-
-    // Search through all days and entries
-    for (int dayIndex = 0; dayIndex < 7; dayIndex++)
     {
-        const sControlDay *day = &aControlTable[dayIndex];
 
-        for (int entryIndex = 0; entryIndex < day->entryCount; entryIndex++)
+        // 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 sControlTemperatureEntry *entry = &day->aTemperatureEntries[entryIndex];
+            const sControlDay *day = &gControlTable[dayIndex];
 
-            // Check if this entry is in the future (next active entry)
+            for (int entryIndex = 0; entryIndex < day->entryCount; entryIndex++)
-            bool isFutureDay = (day->day > currentDay);
-            bool isTodayFutureTime = (day->day == currentDay) &&
-                                     ((entry->timestamp.hour > currentHour) ||
-                                      (entry->timestamp.hour == currentHour &&
-                                       entry->timestamp.minute > currentMinute));
-
-            if (isFutureDay || isTodayFutureTime)
             {
-                // Found next scheduled entry, so determine the previous (active) one
+                const sControlTemperatureEntry *entry = &day->aTemperatureEntries[entryIndex];
-                if (entryIndex > 0)
+
+                // Check if this entry is in the future (next active entry)
+                bool isFutureDay = (day->day > currentDay);
+                bool isTodayFutureTime = (day->day == currentDay) &&
+                                         ((entry->timestamp.hour > currentHour) ||
+                                          (entry->timestamp.hour == currentHour &&
+                                           entry->timestamp.minute > currentMinute));
+
+                if (isFutureDay || isTodayFutureTime)
                 {
-                    // Use previous entry from same day
+
-                    currentControlEntry = day->aTemperatureEntries[entryIndex - 1];
+                    // Found next scheduled entry, so determine the previous (active) one
+                    if (entryIndex > 0)
+                    {
+                        // Use previous entry from same day
+                        gCurrentControlEntry = day->aTemperatureEntries[entryIndex - 1];
+                    }
+                    else if (dayIndex > 0)
+                    {
+                        // Use last entry from previous day
+                        const sControlDay *previousDay = &gControlTable[dayIndex - 1];
+                        gCurrentControlEntry = previousDay->aTemperatureEntries[previousDay->entryCount - 1];
+                    }
+                    else
+                    {
+                        // First entry of the week - wrap to last entry of Sunday
+                        const sControlDay *sunday = &gControlTable[6];
+                        gCurrentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
+                    }
+                    /*
+                    ESP_LOGI(TAG, "Active entry found - Time: %02d:%02d, "
+                             "Return Temp: %lf, Chamber Temp: %lf",
+                             gCurrentControlEntry.timestamp.hour,
+                             gCurrentControlEntry.timestamp.minute,
+                             gCurrentControlEntry.fReturnFlowTemperature,
+                             gCurrentControlEntry.fChamberTemperature);
+                             */
+                    return;
                 }
-                else if (dayIndex > 0)
-                {
-                    // Use last entry from previous day
-                    const sControlDay *previousDay = &aControlTable[dayIndex - 1];
-                    currentControlEntry = previousDay->aTemperatureEntries[previousDay->entryCount - 1];
-                }
-                else
-                {
-                    // First entry of the week - wrap to last entry of Sunday
-                    const sControlDay *sunday = &aControlTable[6];
-                    currentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
-                }
-                /*
-                ESP_LOGI(TAG, "Active entry found - Time: %02d:%02d, "
-                         "Return Temp: %lf, Chamber Temp: %lf",
-                         currentControlEntry.timestamp.hour,
-                         currentControlEntry.timestamp.minute,
-                         currentControlEntry.fReturnFlowTemperature,
-                         currentControlEntry.fChamberTemperature);
-                         */
-                return;
             }
         }
+
+        // If we reached here, current time is after all entries this week
+        // Use the last entry (Sunday evening)
+        const sControlDay *sunday = &gControlTable[6];
+        gCurrentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
+
+        // 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()");
     }
-
-    // If we reached here, current time is after all entries this week
-    // Use the last entry (Sunday evening)
-    const sControlDay *sunday = &aControlTable[6];
-    currentControlEntry = sunday->aTemperatureEntries[sunday->entryCount - 1];
-
-    // ESP_LOGI(TAG, "Using last entry of week - Time: %02d:%02d", currentControlEntry.timestamp.hour, currentControlEntry.timestamp.minute);
 }
 
 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/inputs.c

@@ -49,7 +49,12 @@ void initInputs(void)
         .intr_type = GPIO_INTR_DISABLE             // Disable interrupts
     };
 
-    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;
+    }
 
     xMutexAccessInputs = xSemaphoreCreateRecursiveMutex();
     if (xMutexAccessInputs == NULL)
@@ -94,17 +99,17 @@ 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)
@@ -122,12 +127,19 @@ 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];
     }
 
-    pMeasurement->average10s.fValue = sum / pMeasurement->average10s.bufferCount;
+    if (pMeasurement->average10s.bufferCount == 0U)
+    {
+        pMeasurement->average10s.fValue = 0.0f;
+    }
+    else
+    {
+        pMeasurement->average10s.fValue = sum / pMeasurement->average10s.bufferCount;
+    }
 
     // Average form the last 60sec
     pMeasurement->average60s.samples[pMeasurement->average60s.bufferIndex] = pMeasurement->fCurrentValue;
@@ -144,7 +156,14 @@ void updateAverage(sMeasurement *pMeasurement)
         sum += pMeasurement->average60s.samples[i];
     }
 
-    pMeasurement->average60s.fValue = sum / pMeasurement->average60s.bufferCount;
+    if (pMeasurement->average60s.bufferCount == 0U)
+    {
+        pMeasurement->average60s.fValue = 0.0f;
+    }
+    else
+    {
+        pMeasurement->average60s.fValue = sum / pMeasurement->average60s.bufferCount;
+    }
 
     // Damped current value
     if (pMeasurement->fDampedValue == INITIALISATION_VALUE)

main/metrics.c

@@ -301,23 +301,23 @@ 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];

main/outputs.c

@@ -41,9 +41,26 @@ void initOutputs(void)
         .intr_type = GPIO_INTR_DISABLE                   // Disable interrupts
     };
 
-    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: %s", esp_err_to_name(ret));
+        return;
+    }
+
+    ret = gpio_config(&ioConfBurner);
+    if (ret != ESP_OK)
+    {
+        ESP_LOGE(TAG, "GPIO config failed: %s", esp_err_to_name(ret));
+        return;
+    }
+
+    ret = gpio_config(&ioConfSafetyContact);
+    if (ret != ESP_OK)
+    {
+        ESP_LOGE(TAG, "GPIO config failed: %s", esp_err_to_name(ret));
+        return;
+    }
 
     xMutexAccessOutputs = xSemaphoreCreateRecursiveMutex();
     if (xMutexAccessOutputs == NULL)
@@ -55,7 +72,17 @@ void initOutputs(void)
 
 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 +97,7 @@ void setCirculationPumpState(eOutput in)
             break;
         case DISABLED:
             gpio_set_level(uCirculationPumpGpioPin, 1U); // Switch off Circulation Pump
+            break;
         default:
             break;
         }
@@ -108,6 +136,7 @@ void setBurnerState(eOutput in)
             break;
         case DISABLED:
             gpio_set_level(uBurnerGpioPin, 1U); // Switch off Burner
+            break;
         default:
             break;
         }
@@ -146,6 +175,7 @@ void setSafetyControlState(eOutput in)
             break;
         case DISABLED:
             gpio_set_level(uSafetyContactGpioPin, 1U); // Switch off power for Burner
+            break;
         default:
             break;
         }

main/safety.c

@@ -2,10 +2,12 @@
 #include "freertos/task.h"
 #include "esp_log.h"
 #include <string.h>
+#include <math.h>
 #include "safety.h"
 
 #define PERIODIC_INTERVAL 1U            // run safety checks every 1sec
 #define SENSOR_GRACE_PERIOD (60U * 30U) // period that a sensor can report the same reading in seconds
+#define FLOAT_EPSILON 0.0001f
 
 static const char *TAG = "smart-oil-heater-control-system-safety";
 static SemaphoreHandle_t xMutexAccessSafety = NULL;
@@ -91,7 +93,7 @@ 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 +105,7 @@ void checkSensorSanity(void)
             }
             else
             {
+                sanityChecks[i].uUnchangedCounter = 0U;
                 sanityChecks[i].fSensorTemperatureLast = sCurrentMeasurement.fCurrentValue;
 
                 if (sCurrentMeasurement.fCurrentValue > sanityChecks[i].sSensorLimit.max)
@@ -119,12 +122,10 @@ void checkSensorSanity(void)
                 }
                 else
                 {
-                    sanityChecks[i].uUnchangedCounter = 0U;
                     sanityChecks[i].state = SENSOR_NO_ERROR;
                 }
             }
         }
-        // printf("  state: %u\n", sanityChecks[i].state);
     }
 }
 
@@ -143,7 +144,7 @@ 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/sntp.c

@@ -6,7 +6,7 @@
 #include "sntp.h"
 
 static const char *TAG = "smart-oil-heater-control-system-sntp";
-static eSntpState sntpState = SYNC_NOT_STARTED;
+static volatile eSntpState sntpState = SYNC_NOT_STARTED;
 void time_sync_notification_cb(struct timeval *tv);
 
 void initSntp(void)

main/wifi.c

@@ -13,26 +13,37 @@
 
 #define WIFI_CONNECTED_BIT BIT0
 #define WIFI_FAIL_BIT BIT1
+#define MAX_RETRY_COUNT 10
+#define RETRY_DELAY_MS 1000
 
 static const char *TAG = "smart-oil-heater-control-system-wifi";
 
 static EventGroupHandle_t s_wifi_event_group;
+static int s_retry_num = 0;
+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)
 {
     s_wifi_event_group = xEventGroupCreate();
+    if (s_wifi_event_group == NULL)
+    {
+        ESP_LOGE(TAG, "xEventGroupCreate() failed!");
+        return;
+    }
+
     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));
@@ -84,7 +95,9 @@ void initWifi(void)
     {
         ESP_LOGE(TAG, "Unexpected event");
     }
-    vEventGroupDelete(s_wifi_event_group);
+
+    // Mark initial connection phase complete - do NOT delete the event group
+    s_initial_connect = false;
 }
 
 static void event_handler(void *arg, esp_event_base_t event_base,
@@ -96,13 +109,46 @@ static void event_handler(void *arg, esp_event_base_t event_base,
     }
     else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED)
     {
-        esp_wifi_connect();
+        wifi_event_sta_disconnected_t *event = (wifi_event_sta_disconnected_t *)event_data;
-        ESP_LOGI(TAG, "Retry to connect to the AP");
+        ESP_LOGW(TAG, "Disconnected from AP (reason: %d)", event->reason);
+
+        if (s_initial_connect)
+        {
+            // During initial connection phase, use retry limit
+            if (s_retry_num < MAX_RETRY_COUNT)
+            {
+                vTaskDelay(pdMS_TO_TICKS(RETRY_DELAY_MS));
+                esp_wifi_connect();
+                s_retry_num++;
+                ESP_LOGI(TAG, "Retry to connect to the AP (%d/%d)", s_retry_num, MAX_RETRY_COUNT);
+            }
+            else
+            {
+                xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
+                ESP_LOGE(TAG, "Failed to connect after %d attempts", MAX_RETRY_COUNT);
+            }
+        }
+        else
+        {
+            // After initial connection, always try to reconnect with delay
+            vTaskDelay(pdMS_TO_TICKS(RETRY_DELAY_MS));
+            esp_wifi_connect();
+            ESP_LOGI(TAG, "Attempting to reconnect to the AP...");
+        }
     }
     else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP)
     {
         ip_event_got_ip_t *event = (ip_event_got_ip_t *)event_data;
         ESP_LOGI(TAG, "Got ip:" IPSTR, IP2STR(&event->ip_info.ip));
-        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+        s_retry_num = 0;
+
+        if (s_initial_connect)
+        {
+            xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+        }
+        else
+        {
+            ESP_LOGI(TAG, "Successfully reconnected to AP");
+        }
     }
 }