8 files changed, 144 insertions, 91 deletions

diff --git a/README b/README
deleted file mode 100644
index 823695c..0000000
--- a/README
+++ /dev/null
@@ -1 +0,0 @@
-The beginning of my master's thesis project. Here I will test the broad cybersecurity issues of IoT devices, and hopefully solve them.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e380147
--- /dev/null
+++ b/README.md
@@ -0,0 +1,2 @@
+# The beginning of my master's thesis project.
+Here I will test the MQTT-related issues of IoT devices, and specify how to solve them properly.
diff --git a/firmware/.baud_detected b/firmware/.baud_detected
new file mode 100644
index 0000000..be25b30
--- /dev/null
+++ b/firmware/.baud_detected
@@ -0,0 +1 @@
+115200
diff --git a/firmware/Makefile b/firmware/Makefile
index 0fd1699..0595792 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -9,7 +9,29 @@ BUILD_FLAGS = -D WIFI_SSID="\\\"$(WIFI_SSID)\\\"" \
               -D WIFI_PASS="\\\"$(WIFI_PASS)\\\"" \
               -D MQTT_URI="\\\"$(MQTT_URI)\\\""
 
-.PHONY: build upload monitor clean debug-flags test
+PORT ?= $(shell ls /dev/ttyUSB* /dev/ttyACM* 2>/dev/null | head -n 1)
+
+ifdef BAUD
+  BAUD := $(BAUD)
+else ifneq ("$(wildcard .baud_detected)","")
+  BAUD := $(shell cat .baud_detected)
+else
+  BAUD := 115200
+endif
+
+detect-baud:
+        @echo "[*] Detecting correct baud rate..."
+        @if screen -L -dmS test_screen $(PORT) 74880; then \
+                sleep 1; \
+                grep -q "rst:" screenlog.0 && echo "74880" > .baud_detected || echo "115200" > .baud_detected; \
+                rm -f screenlog.0; \
+                screen -S test_screen -X quit; \
+        else \
+                echo "115200" > .baud_detected; \
+        fi
+        @echo "[✓] Set BAUD=$$(cat .baud_detected)"
+
+.PHONY: build upload monitor clean debug-flags test detect-baud
 
 build:
         @echo "Starting build with SSID=$(WIFI_SSID)"
@@ -20,7 +42,11 @@ upload:
         PLATFORMIO_BUILD_FLAGS="$(BUILD_FLAGS)" pio run -e $(ENV) -t upload
 
 monitor:
-        pio device monitor -e $(ENV)
+        @PORT=$(PORT); \
+        BAUD=$(BAUD); \
+        if [ -z "$$PORT" ]; then echo "[ERROR] Port /dev/ttyUSB* or /dev/ttyACM* not found"; exit 1; fi; \
+        echo "[*] Opening monitor: $$PORT @ $$BAUD baud"; \
+        screen $$PORT $$BAUD
 
 clean:
         pio run -e $(ENV) -t clean
diff --git a/firmware/platformio.ini b/firmware/platformio.ini
index 4f199c3..b106ca7 100644
--- a/firmware/platformio.ini
+++ b/firmware/platformio.ini
@@ -5,4 +5,4 @@ framework = espidf
 monitor_speed = 115200
 platform_packages =
     framework-espidf@3.50500.0
-; board_build.flash_size = 2MB
+board_build.flash_size = 2MB
diff --git a/firmware/src/main.c b/firmware/src/main.c
index 3f186f8..9fa4c61 100644
--- a/firmware/src/main.c
+++ b/firmware/src/main.c
@@ -1,5 +1,7 @@
 #include "esp_event.h"
 #include "esp_log.h"
+#include "esp_netif.h"
+#include "esp_sntp.h"
 #include "esp_system.h"
 #include "esp_timer.h"
 #include "nvs_flash.h"
@@ -8,21 +10,26 @@
 #include "wifi.h"
 
 #include <stdio.h>
+#include <time.h>
+
 static const char *TAG = "app";
+static EventGroupHandle_t wifi_event_group;
+#define WIFI_CONNECTED_BIT BIT0
 
 /**
- * @brief Initialize NVS (Non-Volatile Storage) flash storage, handling full or
- * incompatible pages.
- *
- * This function checks the NVS flash storage to ensure that there is enough
- * space and that the version of NVS is compatible. If the partition is full or
- * incompatible, it will erase the NVS partition and attempt initialization
- * again.
- *
- * @return esp_err_t
- * - ESP_OK: Initialization successful.
- * - Other error codes if initialization or erasure fails.
- */
+* @brief Initialize NVS (Non-Volatile Storage) flash storage, handling full or
+* incompatible pages.
+*
+* This function checks the NVS flash storage to ensure that there is enough
+* space and that the version of NVS is compatible. If the partition
+is full or
+* incompatible, it will erase the NVS partition and attempt initialization
+* again.
+*
+* @return esp_err_t
+* - ESP_OK: Initialization successful.
+* - Other error codes if initialization or erasure fails.
+*/
 static esp_err_t nvs_flash_init_check(void)
 {
         esp_err_t ret = nvs_flash_init();
@@ -31,13 +38,7 @@ static esp_err_t nvs_flash_init_check(void)
             ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
                 ESP_LOGW(TAG,
                          "NVS partition is full or incompatible, erasing...");
-                ret = nvs_flash_erase();
-
-                if (ret != ESP_OK) {
-                        ESP_LOGE(TAG, "Failed to erase NVS partition (%s)",
-                                 esp_err_to_name(ret));
-                        return ret;
-                }
+                ESP_ERROR_CHECK(nvs_flash_erase());
                 ret = nvs_flash_init();
         }
 
@@ -64,69 +65,88 @@ static esp_err_t nvs_flash_init_check(void)
  * - ESP_OK: If initialization is successful.
  * - Other error codes if initialization fails.
  */
-static esp_err_t init_component(esp_err_t (*init_func)(void),
-                                const char *component_name)
+static void wifi_event_handler(void *arg, esp_event_base_t event_base,
+                               int32_t event_id, void *event_data)
 {
-        esp_err_t ret = init_func();
-
-        if (ret != ESP_OK) {
-                ESP_LOGE(TAG, "Failed to initialize %s (%s)", component_name,
-                         esp_err_to_name(ret));
-                return ret;
+        if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+                esp_wifi_connect();
+        } else if (event_base == WIFI_EVENT &&
+                   event_id == WIFI_EVENT_STA_DISCONNECTED) {
+                ESP_LOGW(TAG, "Wi-Fi disconnected, reconnecting...");
+                esp_wifi_connect();
+                xEventGroupClearBits(wifi_event_group, WIFI_CONNECTED_BIT);
+        } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
+                ESP_LOGI(TAG, "Wi-Fi connected and got IP!");
+                xEventGroupSetBits(wifi_event_group, WIFI_CONNECTED_BIT);
         }
-
-        return ESP_OK;
 }
 
 /**
- * @brief Initializes all the essential components for the application.
- *
- * This function initializes the NVS storage, network interface, and event loop
- * in sequence. If any of these components fail to initialize, the function
- * returns an error, and the application will stop early.
- *
- * @return esp_err_t
- * - ESP_OK: If all components are successfully initialized.
- * - ESP_FAIL: If any component fails to initialize.
+ * @TODO missing doc
  */
-esp_err_t init_app_components(void)
+static void obtain_time(void)
 {
-        if (init_component(nvs_flash_init_check, "NVS") != ESP_OK) {
-                ESP_LOGE(TAG, "NVS initialization failed, aborting app start.");
-                return ESP_FAIL;
+        ESP_LOGI(TAG, "Starting SNTP time sync...");
+        sntp_setoperatingmode(SNTP_OPMODE_POLL);
+        sntp_setservername(0, "pool.ntp.org");
+        sntp_init();
+
+        time_t now = 0;
+        struct tm timeinfo = {0};
+        int retry = 0;
+        const int retry_count = 10;
+
+        while (timeinfo.tm_year < (2022 - 1900) && ++retry < retry_count) {
+                ESP_LOGI(TAG, "Waiting for system time to be set... (%d/%d)",
+                         retry, retry_count);
+                vTaskDelay(pdMS_TO_TICKS(1000));
+                time(&now);
+                localtime_r(&now, &timeinfo);
         }
 
-        if (init_component(esp_netif_init, "network interface") != ESP_OK)
-                return ESP_FAIL;
-
-        if (init_component(esp_event_loop_create_default, "event loop") !=
-            ESP_OK)
-                return ESP_FAIL;
-
-        return ESP_OK;
+        if (timeinfo.tm_year >= (2022 - 1900)) {
+                char buf[64];
+                strftime(buf, sizeof(buf), "%c", &timeinfo);
+                ESP_LOGI(TAG, "System time synchronized: %s", buf);
+        } else {
+                ESP_LOGW(TAG, "Failed to synchronize time.");
+        }
 }
 
 /**
- * @brief Main entry point of the application.
- *
- * This function is responsible for initializing the core components of the
- * application, including the NVS storage, network interface, and event loop. If
- * any initialization step fails, the application will log the error and stop.
- *
- * After initialization, this function will configure the WiFi station and start
- * the MQTT client.
- */
-
+* @brief Main entry point of the application.
+*
+* This function is responsible for initializing the core components
+of the
+* application, including the NVS storage, network interface, and event loop. If
+* any initialization step fails, the application will log the error
+and stop.
+*
+* After initialization, this function will configure the WiFi station and start
+* the MQTT client.
+*/
 void app_main(void)
 {
-        if (init_app_components() != ESP_OK) {
-                ESP_LOGE(TAG, "App initialization failed, aborting.");
-                return;
-        }
+        ESP_ERROR_CHECK(nvs_flash_init_check());
+        ESP_ERROR_CHECK(esp_netif_init());
+        ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+        wifi_event_group = xEventGroupCreate();
 
-        ESP_LOGI(TAG, "Initializing WiFi in station mode");
+        ESP_LOGI(TAG, "Initializing WiFi (station mode)");
         wifi_init_sta();
 
-        ESP_LOGI(TAG, "Starting MQTT client");
+        ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
+                                                   &wifi_event_handler, NULL));
+        ESP_ERROR_CHECK(esp_event_handler_register(
+            IP_EVENT, IP_EVENT_STA_GOT_IP, &wifi_event_handler, NULL));
+
+        ESP_LOGI(TAG, "Waiting for Wi-Fi connection...");
+        xEventGroupWaitBits(wifi_event_group, WIFI_CONNECTED_BIT, pdFALSE,
+                            pdFALSE, portMAX_DELAY);
+
+        obtain_time();
+
+        ESP_LOGI(TAG, "Starting MQTT client...");
         mqtt_app_start();
 }
diff --git a/firmware/src/mqtt.c b/firmware/src/mqtt.c
index b3553eb..a726534 100644
--- a/firmware/src/mqtt.c
+++ b/firmware/src/mqtt.c
@@ -11,7 +11,6 @@
 static const char *TAG = "mqtt";
 static esp_mqtt_client_handle_t client;
 
-// Zliczniki i pomiary
 static long long last_sent = 0;
 static long long last_rtt = 0;
 static long long last_rtt_prev = 0;
@@ -20,7 +19,6 @@ static int received_count = 0;
 static unsigned long tx_bytes = 0;
 static unsigned long rx_bytes = 0;
 
-// Kanały pomiarów
 #define TOPIC_RTT "device/metrics/rtt"
 #define TOPIC_JITTER "device/metrics/jitter"
 #define TOPIC_LOSS "device/metrics/loss"
@@ -29,6 +27,9 @@ static unsigned long rx_bytes = 0;
 #define TOPIC_NET_TX "device/metrics/net_tx"
 #define TOPIC_NET_RX "device/metrics/net_rx"
 
+#define TOPIC_IN "device/echo/in"
+#define TOPIC_OUT "device/echo/out"
+
 static void mqtt_event_handler(void *handler_args, esp_event_base_t base,
                                int32_t event_id, void *event_data)
 {
@@ -37,13 +38,12 @@ static void mqtt_event_handler(void *handler_args, esp_event_base_t base,
         switch (event->event_id) {
         case MQTT_EVENT_CONNECTED:
                 ESP_LOGI(TAG, "MQTT connected!");
-                esp_mqtt_client_subscribe(event->client, PUB_TOPIC, 1);
+                esp_mqtt_client_subscribe(event->client, TOPIC_IN, 1);
                 break;
 
         case MQTT_EVENT_DATA: {
                 char topic[event->topic_len + 1];
                 char data[event->data_len + 1];
-
                 memcpy(topic, event->topic, event->topic_len);
                 topic[event->topic_len] = '\0';
                 memcpy(data, event->data, event->data_len);
@@ -61,8 +61,9 @@ static void mqtt_event_handler(void *handler_args, esp_event_base_t base,
                                 last_rtt_prev = last_rtt;
                                 last_rtt = rtt;
                                 received_count++;
+
                                 esp_mqtt_client_publish(
-                                    event->client, SUB_TOPIC, data, 0, 1, 0);
+                                    event->client, TOPIC_OUT, data, 0, 1, 0);
                                 tx_bytes += strlen(data);
                         }
                 }
@@ -91,7 +92,7 @@ static void mqtt_test_task(void *pvParameters)
                 last_sent = esp_timer_get_time() / 1000ULL;
                 char msg[32];
                 snprintf(msg, sizeof(msg), "%lld", last_sent);
-                esp_mqtt_client_publish(client, PUB_TOPIC, msg, 0, 1, 0);
+                esp_mqtt_client_publish(client, TOPIC_IN, msg, 0, 1, 0);
                 tx_bytes += strlen(msg);
                 sent_count++;
                 vTaskDelay(pdMS_TO_TICKS(delay_ms));
@@ -106,7 +107,6 @@ static void mqtt_metrics_task(void *pvParameters)
                 long long dt = (now - last_time) / 1000ULL;
                 last_time = now;
 
-                // RTT
                 if (last_rtt > 0) {
                         char buf[32];
                         snprintf(buf, sizeof(buf), "%lld", last_rtt);
@@ -115,7 +115,6 @@ static void mqtt_metrics_task(void *pvParameters)
                         tx_bytes += strlen(buf);
                 }
 
-                // Jitter
                 if (last_rtt_prev > 0) {
                         long long jitter = llabs(last_rtt - last_rtt_prev);
                         char buf[32];
@@ -125,23 +124,21 @@ static void mqtt_metrics_task(void *pvParameters)
                         tx_bytes += strlen(buf);
                 }
 
-                // Packet loss
-                int loss = sent_count > 0 ? (sent_count - received_count) *
-                                                100 / sent_count
-                                          : 0;
+                int loss =
+                    (sent_count > 0)
+                        ? ((sent_count - received_count) * 100 / sent_count)
+                        : 0;
                 char buf_loss[16];
                 snprintf(buf_loss, sizeof(buf_loss), "%d", loss);
                 esp_mqtt_client_publish(client, TOPIC_LOSS, buf_loss, 0, 1, 0);
                 tx_bytes += strlen(buf_loss);
 
-                // Throughput
                 char buf_thr[16];
                 snprintf(buf_thr, sizeof(buf_thr), "%d", received_count);
                 esp_mqtt_client_publish(client, TOPIC_THROUGHPUT, buf_thr, 0, 1,
                                         0);
                 tx_bytes += strlen(buf_thr);
 
-                // CPU usage
                 UBaseType_t free_heap = xPortGetFreeHeapSize();
                 UBaseType_t min_free_heap = xPortGetMinimumEverFreeHeapSize();
                 int cpu_load =
@@ -156,16 +153,15 @@ static void mqtt_metrics_task(void *pvParameters)
                 esp_mqtt_client_publish(client, TOPIC_CPU, buf_cpu, 0, 1, 0);
                 tx_bytes += strlen(buf_cpu);
 
-                // Network TX/RX bytes
                 char buf_tx[32], buf_rx[32];
                 snprintf(buf_tx, sizeof(buf_tx), "%lu", tx_bytes);
                 snprintf(buf_rx, sizeof(buf_rx), "%lu", rx_bytes);
                 esp_mqtt_client_publish(client, TOPIC_NET_TX, buf_tx, 0, 1, 0);
                 esp_mqtt_client_publish(client, TOPIC_NET_RX, buf_rx, 0, 1, 0);
 
-                // Reset liczniki na kolejny interwał
                 tx_bytes = 0;
                 rx_bytes = 0;
+                sent_count = 0;
                 received_count = 0;
 
                 vTaskDelay(pdMS_TO_TICKS(1000));
diff --git a/firmware/src/wifi_scan.c b/firmware/src/wifi_scan.c
index 02bb451..07f3dc7 100644
--- a/firmware/src/wifi_scan.c
+++ b/firmware/src/wifi_scan.c
@@ -12,12 +12,19 @@
 #define WIFI_SCAN_TASK_NAME "wifi_scan_task"
 
 /**
- * @brief Task to perform WiFi scanning asynchronously.
+ * @brief Asynchronous WiFi scanning task for ESP32 with FreeRTOS.
  *
- * Starts a WiFi scan, polls for scan completion,
- * retrieves and logs the found access points, then deletes itself.
+ * Configures and initiates a non-blocking WiFi scan on the specified or all
+ * channels, including hidden networks if enabled. Periodically polls for scan
+ * completion without blocking other tasks, retrieves discovered access points
+ * up to a defined maximum, and logs each AP's SSID and signal strength (RSSI).
  *
- * @param pvParameter Task parameter (unused).
+ * After logging, the task self-deletes to free system resources.
+ *
+ * This design ensures WiFi scanning runs in the background, preserving system
+ * responsiveness and maintaining real-time operation in embedded applications.
+ *
+ * @param pvParameter Pointer to task parameters (unused).
  */
 static void wifi_scan_task(void *pvParameter)
 {
@@ -36,13 +43,15 @@ static void wifi_scan_task(void *pvParameter)
         while (true) {
                 uint16_t finished_ap_count = 0;
                 ESP_ERROR_CHECK(esp_wifi_scan_get_ap_num(&finished_ap_count));
-                if (finished_ap_count > 0)
+                if (finished_ap_count > 0) {
                         break;
+                }
                 vTaskDelay(pdMS_TO_TICKS(WIFI_SCAN_POLL_INTERVAL_MS));
         }
 
         ESP_ERROR_CHECK(esp_wifi_scan_get_ap_records(&ap_count, ap_info));
         ESP_LOGI("wifi_scan", "Found %d access points:", ap_count);
+
         for (uint16_t ap_index = 0; ap_index < ap_count; ++ap_index) {
                 ESP_LOGI("wifi_scan", "%d: SSID: %s, RSSI: %d", ap_index + 1,
                          ap_info[ap_index].ssid, ap_info[ap_index].rssi);