perf: tune BLE scanning performance, switch over to NimBLE

CMakeLists.txt

@@ -3,4 +3,4 @@ cmake_minimum_required(VERSION 3.22)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 # "Trim" the build. Include the minimal set of components, main, and anything it depends on.
 idf_build_set_property(MINIMAL_BUILD ON)
-project(esp-anchor)
+project(esp-anchor VERSION 0.2.0)

components/ble_scanner/CMakeLists.txt

@@ -1,5 +1,5 @@
 idf_component_register(
     SRCS "src/ble_scanner.c"
     INCLUDE_DIRS "include"
-    REQUIRES bt esp_event
+    REQUIRES esp_event bt
 )

components/ble_scanner/Kconfig

@@ -0,0 +1,21 @@
+menu "BLE Scanner"
+
+    config BLE_SCAN_INTERVAL_MS
+        int "Scan interval (ms)"
+        default 100
+        range 3 10240
+        help
+            Time between the start of consecutive scan windows (0.625 ms units
+            internally). Larger values reduce duty cycle and leave more airtime
+            for WiFi.
+
+    config BLE_SCAN_WINDOW_MS
+        int "Scan window (ms)"
+        default 80
+        range 3 10240
+        help
+            Duration of each active scan window. Must be <= scan interval.
+            Default 80 ms gives 80% duty cycle (up from 50% with previous
+            defaults) without starving WiFi TX.
+
+endmenu

components/ble_scanner/include/ble_scanner.h

@@ -2,16 +2,29 @@
 
 #include <stdint.h>
 
-/**
- * Called for every unique BLE advertisement received.
- * tag_id is a null-terminated string: "aa:bb:cc:dd:ee:ff"
- * rssi is in dBm (negative).
- */
-typedef void (*ble_scanner_cb_t)(const char *tag_id, int8_t rssi);
+typedef enum {
+    BLE_BEACON_IBEACON,
+    BLE_BEACON_ALTBEACON,
+    BLE_BEACON_EDDYSTONE_UID,
+    BLE_BEACON_EDDYSTONE_URL,
+} ble_beacon_type_t;
+
+typedef struct {
+    ble_beacon_type_t type;
+    char id[64];       /* beacon identifier; encoding varies by type:
+                          iBeacon:        "UUID-MAJOR-MINOR"
+                          AltBeacon:      40-char hex beacon ID
+                          Eddystone UID:  "NAMESPACE.INSTANCE" hex
+                          Eddystone URL:  decoded URL string          */
+    int8_t tx_power;   /* calibrated TX power from beacon payload */
+    int8_t rssi;       /* measured signal strength */
+} ble_beacon_t;
+
+typedef void (*ble_scanner_cb_t)(const ble_beacon_t *beacon);
 
 /**
- * Initialise the Bluedroid BLE stack and register the scan callback.
- * Must be called once after esp_bt_controller_init / esp_bluedroid_init.
+ * Initialise the NimBLE stack and register the scan callback. Must be called
+ * once before ble_scanner_start(). Starts the NimBLE host task internally.
  */
 void ble_scanner_init(ble_scanner_cb_t cb);
 

components/ble_scanner/src/ble_scanner.c

@@ -1,89 +1,218 @@
 #include "ble_scanner.h"
-#include "esp_bt.h"
-#include "esp_bt_main.h"
-#include "esp_gap_ble_api.h"
+#include "nimble/nimble_port.h"
+#include "nimble/nimble_port_freertos.h"
+#include "host/ble_hs.h"
+#include "host/ble_gap.h"
 #include "esp_log.h"
 #include <stdio.h>
-#include <string.h>
+
+static int gap_event_cb(struct ble_gap_event *event, void *arg);
 
 #define TAG "ble_scanner"
 
-static ble_scanner_cb_t s_cb = NULL;
+/* Units: 1 tick = 0.625 ms */
+#define MS_TO_BLE_TICKS(ms)  ((ms) * 1000 / 625)
 
-/* Passive scan: 100ms interval, 50ms window (50% duty cycle) */
-static esp_ble_scan_params_t s_scan_params = {
-    .scan_type          = BLE_SCAN_TYPE_PASSIVE,
-    .own_addr_type      = BLE_ADDR_TYPE_PUBLIC,
-    .scan_filter_policy = BLE_SCAN_FILTER_ALLOW_ALL,
-    .scan_interval      = 0xA0,  /* 100ms: 0xA0 * 0.625ms */
-    .scan_window        = 0x50,  /* 50ms:  0x50 * 0.625ms */
-    .scan_duplicate     = BLE_SCAN_DUPLICATE_DISABLE,
+static ble_scanner_cb_t s_cb           = NULL;
+static bool             s_scan_active  = false;
+static uint8_t          s_own_addr_type;
+
+/* Eddystone URL expansion codes 0x00-0x0D per spec */
+static const char *const s_url_expansions[] = {
+    ".com/", ".org/", ".edu/", ".net/",
+    ".info/", ".biz/", ".gov/", ".com",
+    ".org", ".edu", ".net", ".info", ".biz", ".gov",
 };
 
-static void gap_event_handler(esp_gap_ble_cb_event_t event,
-                               esp_ble_gap_cb_param_t *param)
+/*
+ * iBeacon: AD type 0xFF, company {0x4C,0x00}, subtype {0x02,0x15}
+ * value layout: company[2] subtype[2] UUID[16] major[2] minor[2] tx_power[1]
+ */
+static bool try_ibeacon(const uint8_t *val, uint8_t vlen, ble_beacon_t *out)
 {
-    switch (event) {
-    case ESP_GAP_BLE_SCAN_PARAM_SET_COMPLETE_EVT:
-        if (param->scan_param_cmpl.status == ESP_BT_STATUS_SUCCESS) {
-            esp_ble_gap_start_scanning(0);  /* 0 = scan indefinitely */
+    if (vlen < 25 || val[0] != 0x4C || val[1] != 0x00
+                  || val[2] != 0x02 || val[3] != 0x15)
+        return false;
+
+    const uint8_t *u = val + 4;
+    snprintf(out->id, sizeof(out->id),
+             "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x"
+             "-%02x%02x%02x%02x%02x%02x-%u-%u",
+             u[0],u[1],u[2],u[3], u[4],u[5], u[6],u[7], u[8],u[9],
+             u[10],u[11],u[12],u[13],u[14],u[15],
+             (unsigned)((u[16] << 8) | u[17]),
+             (unsigned)((u[18] << 8) | u[19]));
+    out->tx_power = (int8_t)val[24];
+    out->type = BLE_BEACON_IBEACON;
+    return true;
+}
+
+/*
+ * AltBeacon: AD type 0xFF, bytes[2..3]=={0xBE,0xAC}
+ * value layout: mfg_id[2] beacon_code[2] beacon_id[20] tx_power[1] reserved[1]
+ */
+static bool try_altbeacon(const uint8_t *val, uint8_t vlen, ble_beacon_t *out)
+{
+    if (vlen < 26 || val[2] != 0xBE || val[3] != 0xAC)
+        return false;
+
+    const uint8_t *id = val + 4;
+    for (int i = 0; i < 20; i++)
+        snprintf(out->id + i * 2, 3, "%02x", id[i]);
+    out->id[40] = '\0';
+    out->tx_power = (int8_t)val[24];
+    out->type = BLE_BEACON_ALTBEACON;
+    return true;
+}
+
+/*
+ * Eddystone: AD type 0x16, service UUID {0xAA,0xFE}
+ * value layout: uuid[2] frame_type[1] ...
+ *   UID frame (0x00): tx_power[1] namespace[10] instance[6]
+ *   URL frame (0x10): tx_power[1] scheme[1] encoded_url[...]
+ */
+static bool try_eddystone(const uint8_t *val, uint8_t vlen, ble_beacon_t *out)
+{
+    if (vlen < 4 || val[0] != 0xAA || val[1] != 0xFE)
+        return false;
+
+    uint8_t frame = val[2];
+
+    if (frame == 0x00) {
+        if (vlen < 20) return false;
+        out->tx_power = (int8_t)val[3];
+        const uint8_t *ns   = val + 4;
+        const uint8_t *inst = val + 14;
+        snprintf(out->id, sizeof(out->id),
+                 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"
+                 ".%02x%02x%02x%02x%02x%02x",
+                 ns[0],ns[1],ns[2],ns[3],ns[4],ns[5],ns[6],ns[7],ns[8],ns[9],
+                 inst[0],inst[1],inst[2],inst[3],inst[4],inst[5]);
+        out->type = BLE_BEACON_EDDYSTONE_UID;
+        return true;
+    }
+
+    if (frame == 0x10) {
+        if (vlen < 5) return false;
+        out->tx_power = (int8_t)val[3];
+        static const char *const schemes[] = {
+            "http://www.", "https://www.", "http://", "https://",
+        };
+        const char *scheme = (val[4] < 4) ? schemes[val[4]] : "";
+        int pos = snprintf(out->id, sizeof(out->id), "%s", scheme);
+        for (uint8_t i = 5; i < vlen; i++) {
+            uint8_t c = val[i];
+            int rem = (int)sizeof(out->id) - pos;
+            if (rem <= 1) break;
+            int n;
+            if (c < (uint8_t)(sizeof(s_url_expansions) / sizeof(s_url_expansions[0]))) {
+                n = snprintf(out->id + pos, rem, "%s", s_url_expansions[c]);
             } else {
-            ESP_LOGE(TAG, "Scan param set failed: %d", param->scan_param_cmpl.status);
+                out->id[pos] = (char)c;
+                n = 1;
             }
-        break;
-
-    case ESP_GAP_BLE_SCAN_START_COMPLETE_EVT:
-        if (param->scan_start_cmpl.status != ESP_BT_STATUS_SUCCESS) {
-            ESP_LOGE(TAG, "Scan start failed: %d", param->scan_start_cmpl.status);
+            pos += (n >= rem) ? rem - 1 : n;
         }
-        break;
-
-    case ESP_GAP_BLE_SCAN_RESULT_EVT: {
-        esp_ble_gap_cb_param_t *p = param;
-        if (p->scan_rst.search_evt == ESP_GAP_SEARCH_INQ_RES_EVT && s_cb) {
-            char tag_id[18];
-            uint8_t *a = p->scan_rst.bda;
-            snprintf(tag_id, sizeof(tag_id),
-                     "%02x:%02x:%02x:%02x:%02x:%02x",
-                     a[0], a[1], a[2], a[3], a[4], a[5]);
-            s_cb(tag_id, p->scan_rst.rssi);
-        }
-        break;
+        out->id[sizeof(out->id) - 1] = '\0';
+        out->type = BLE_BEACON_EDDYSTONE_URL;
+        return true;
     }
 
-    case ESP_GAP_BLE_SCAN_STOP_COMPLETE_EVT:
-        ESP_LOGI(TAG, "Scan stopped");
-        break;
+    return false;
+}
 
-    default:
+/*
+ * Walk BLE advertisement data (sequence of length-type-value records) and
+ * attempt to match iBeacon, AltBeacon, or Eddystone. Returns true on match.
+ */
+static bool parse_beacon(const uint8_t *data, uint8_t len, ble_beacon_t *out)
+{
+    int pos = 0;
+    while (pos < (int)len) {
+        uint8_t ad_len = data[pos];
+        if (ad_len == 0 || pos + ad_len >= (int)len)
             break;
+        uint8_t  ad_type = data[pos + 1];
+        const uint8_t *val  = data + pos + 2;
+        uint8_t  vlen    = ad_len - 1;
+
+        if (ad_type == 0xFF) {
+            if (try_ibeacon(val, vlen, out))   return true;
+            if (try_altbeacon(val, vlen, out)) return true;
+        } else if (ad_type == 0x16) {
+            if (try_eddystone(val, vlen, out)) return true;
         }
+        pos += 1 + ad_len;
+    }
+    return false;
+}
+
+static void do_start_scan(void)
+{
+    struct ble_gap_disc_params p = {
+        .itvl              = MS_TO_BLE_TICKS(CONFIG_BLE_SCAN_INTERVAL_MS),
+        .window            = MS_TO_BLE_TICKS(CONFIG_BLE_SCAN_WINDOW_MS),
+        .filter_policy     = 0,   /* accept all, no whitelist */
+        .limited           = 0,
+        .passive           = 1,
+        .filter_duplicates = 0,   /* report every advertisement for live RSSI */
+    };
+    int rc = ble_gap_disc(s_own_addr_type, BLE_HS_FOREVER, &p, gap_event_cb, NULL);
+    if (rc != 0)
+        ESP_LOGE(TAG, "ble_gap_disc failed: %d", rc);
+}
+
+static int gap_event_cb(struct ble_gap_event *event, void *arg)
+{
+    if (event->type == BLE_GAP_EVENT_DISC && s_cb) {
+        ble_beacon_t beacon = {0};
+        beacon.rssi = event->disc.rssi;
+        if (parse_beacon(event->disc.data, event->disc.length_data, &beacon))
+            s_cb(&beacon);
+    }
+    return 0;
+}
+
+static void on_nimble_sync(void)
+{
+    ble_hs_id_infer_auto(0, &s_own_addr_type);
+    if (s_scan_active)
+        do_start_scan();
+}
+
+static void on_nimble_reset(int reason)
+{
+    ESP_LOGW(TAG, "NimBLE reset: %d", reason);
+}
+
+static void nimble_host_task(void *arg)
+{
+    nimble_port_run();
+    nimble_port_freertos_deinit();
 }
 
 void ble_scanner_init(ble_scanner_cb_t cb)
 {
     s_cb = cb;
-
-    ESP_ERROR_CHECK(esp_bt_controller_mem_release(ESP_BT_MODE_CLASSIC_BT));
-
-    esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
-    ESP_ERROR_CHECK(esp_bt_controller_init(&bt_cfg));
-    ESP_ERROR_CHECK(esp_bt_controller_enable(ESP_BT_MODE_BLE));
-    ESP_ERROR_CHECK(esp_bluedroid_init());
-    ESP_ERROR_CHECK(esp_bluedroid_enable());
-
-    ESP_ERROR_CHECK(esp_ble_gap_register_callback(gap_event_handler));
-    ESP_LOGI(TAG, "BLE scanner initialised");
+    nimble_port_init();
+    ble_hs_cfg.sync_cb  = on_nimble_sync;
+    ble_hs_cfg.reset_cb = on_nimble_reset;
+    nimble_port_freertos_init(nimble_host_task);
+    ESP_LOGI(TAG, "BLE scanner initialised (NimBLE)");
 }
 
 void ble_scanner_start(void)
 {
-    ESP_LOGI(TAG, "Starting BLE scan");
-    ESP_ERROR_CHECK(esp_ble_gap_set_scan_params(&s_scan_params));
-    /* Scanning begins in the param-set callback once confirmed */
+    ESP_LOGI(TAG, "Starting BLE scan (interval=%dms window=%dms)",
+             CONFIG_BLE_SCAN_INTERVAL_MS, CONFIG_BLE_SCAN_WINDOW_MS);
+    s_scan_active = true;
+    if (ble_hs_synced())
+        do_start_scan();
+    /* else: on_nimble_sync() will start scanning once host syncs with controller */
 }
 
 void ble_scanner_stop(void)
 {
-    esp_ble_gap_stop_scanning();
+    s_scan_active = false;
+    ble_gap_disc_cancel();
 }

components/config_store/src/config_store.c

@@ -9,6 +9,8 @@
 #define KEY_PROV         "provisioned"
 #define KEY_HOST         "mqtt_host"
 #define KEY_PORT         "mqtt_port"
+#define KEY_SCHEMA_VER   "schema_ver"
+#define CURRENT_SCHEMA_VER 1
 
 static const char *TAG = "config_store";
 
@@ -20,7 +22,22 @@ esp_err_t config_store_init(void)
         ESP_ERROR_CHECK(nvs_flash_erase());
         err = nvs_flash_init();
     }
-    return err;
+    if (err != ESP_OK) return err;
+
+    nvs_handle_t h;
+    err = nvs_open(NS, NVS_READWRITE, &h);
+    if (err != ESP_OK) return err;
+
+    uint8_t schema_ver = 0;
+    nvs_get_u8(h, KEY_SCHEMA_VER, &schema_ver);
+    if (schema_ver < CURRENT_SCHEMA_VER) {
+        /* Add migration steps here for future schema changes */
+        nvs_set_u8(h, KEY_SCHEMA_VER, CURRENT_SCHEMA_VER);
+        nvs_commit(h);
+        ESP_LOGI(TAG, "NVS schema migrated %u -> %u", schema_ver, CURRENT_SCHEMA_VER);
+    }
+    nvs_close(h);
+    return ESP_OK;
 }
 
 bool config_store_is_provisioned(void)

components/mqtt_publisher/include/mqtt_publisher.h

@@ -13,6 +13,7 @@
 #define MQTT_DESELECTED_BIT           BIT4
 #define MQTT_FACTORY_RESET_BIT        BIT5
 #define MQTT_RECONFIGURE_SETTINGS_BIT BIT6
+#define MQTT_OTA_BIT                  BIT7
 
 /* Populated by handle_cmd() before MQTT_RECONFIGURE_SETTINGS_BIT is set.
  * All fields are optional — empty string means "not provided, leave unchanged". */
@@ -27,19 +28,36 @@ typedef struct {
  *  MQTT_RECONFIGURE_SETTINGS_BIT fires; must be read before the next MQTT event. */
 const mqtt_reconfigure_data_t *mqtt_publisher_get_reconfigure_data(void);
 
+typedef struct {
+    char url[256];
+    char version[32];
+} mqtt_ota_data_t;
+
+/** Returns a pointer to the last parsed OTA payload. Valid only after
+ *  MQTT_OTA_BIT fires; must be read before the next MQTT event. */
+const mqtt_ota_data_t *mqtt_publisher_get_ota_data(void);
+
+/** Publish OTA status to localiser/sensor/{id}/ota. Non-blocking (QoS 1). */
+void mqtt_publisher_send_ota_status(const char *status, const char *version);
+
 /**
  * Initialise and connect the MQTT client.
  *
  * sensor_id   — stable anchor ID string (e.g. "anchor_a1b2c3")
  * broker_uri  — e.g. "mqtt://192.168.1.100:1883"
  * evt_group   — FreeRTOS event group; publisher sets bits above on events
+ * version     — firmware version string included in announce payload and version query responses
  */
 esp_err_t mqtt_publisher_init(const char *sensor_id,
                                const char *broker_uri,
-                               EventGroupHandle_t evt_group);
+                               EventGroupHandle_t evt_group,
+                               const char *version);
 
 /** Publish an RSSI reading. Non-blocking (QoS 1). */
 void mqtt_publisher_send_rssi(const char *tag_id, int8_t rssi);
 
+/** Publish a parsed beacon reading with type, id, tx_power and rssi. Non-blocking (QoS 1). */
+void mqtt_publisher_send_beacon(const char *type, const char *id, int8_t tx_power, int8_t rssi);
+
 /** Publish the announce message (empty payload). */
 void mqtt_publisher_announce(void);

components/mqtt_publisher/src/mqtt_publisher.c

@@ -7,21 +7,30 @@
 
 #define TAG "mqtt_publisher"
 #define TOPIC_PREFIX "localiser/sensor"
+#define TOPIC_OTA_BROADCAST "localiser/ota"
 
 static esp_mqtt_client_handle_t  s_client          = NULL;
 static char                      s_sensor_id[32];
+static char                      s_firmware_version[32];
 static EventGroupHandle_t        s_evt             = NULL;
 static mqtt_reconfigure_data_t   s_reconfigure_data;
+static mqtt_ota_data_t           s_ota_data;
 
 const mqtt_reconfigure_data_t *mqtt_publisher_get_reconfigure_data(void)
 {
     return &s_reconfigure_data;
 }
 
+const mqtt_ota_data_t *mqtt_publisher_get_ota_data(void)
+{
+    return &s_ota_data;
+}
+
 /* Pre-built topic strings */
 static char s_topic_rssi[96];
 static char s_topic_announce[96];
 static char s_topic_cmd[96];
+static char s_topic_ota[96];
 
 static void build_topics(void)
 {
@@ -31,6 +40,8 @@ static void build_topics(void)
              "%s/%s/announce", TOPIC_PREFIX, s_sensor_id);
     snprintf(s_topic_cmd,      sizeof(s_topic_cmd),
              "%s/%s/cmd",      TOPIC_PREFIX, s_sensor_id);
+    snprintf(s_topic_ota,      sizeof(s_topic_ota),
+             "%s/%s/ota",      TOPIC_PREFIX, s_sensor_id);
 }
 
 static void handle_cmd(const char *data, int data_len)
@@ -50,6 +61,16 @@ static void handle_cmd(const char *data, int data_len)
         else if (strcmp(a, "selected")        == 0) xEventGroupSetBits(s_evt, MQTT_SELECTED_BIT);
         else if (strcmp(a, "deselected")      == 0) xEventGroupSetBits(s_evt, MQTT_DESELECTED_BIT);
         else if (strcmp(a, "factory_reset")   == 0) xEventGroupSetBits(s_evt, MQTT_FACTORY_RESET_BIT);
+        else if (strcmp(a, "version")         == 0) mqtt_publisher_announce();
+        else if (strcmp(a, "ota") == 0) {
+            memset(&s_ota_data, 0, sizeof(s_ota_data));
+            cJSON *url_j = cJSON_GetObjectItemCaseSensitive(root, "url");
+            cJSON *ver_j = cJSON_GetObjectItemCaseSensitive(root, "version");
+            if (cJSON_IsString(url_j)) strncpy(s_ota_data.url,     url_j->valuestring, sizeof(s_ota_data.url)     - 1);
+            if (cJSON_IsString(ver_j)) strncpy(s_ota_data.version, ver_j->valuestring, sizeof(s_ota_data.version) - 1);
+            if (s_ota_data.url[0] != '\0') xEventGroupSetBits(s_evt, MQTT_OTA_BIT);
+            else ESP_LOGW(TAG, "OTA cmd missing url");
+        }
         else if (strcmp(a, "reconfigure_settings") == 0) {
             memset(&s_reconfigure_data, 0, sizeof(s_reconfigure_data));
             cJSON *ssid_j  = cJSON_GetObjectItemCaseSensitive(root, "ssid");
@@ -75,6 +96,7 @@ static void mqtt_event_handler(void *arg, esp_event_base_t base,
     case MQTT_EVENT_CONNECTED:
         ESP_LOGI(TAG, "Connected to broker");
         esp_mqtt_client_subscribe(s_client, s_topic_cmd, 1);
+        esp_mqtt_client_subscribe(s_client, TOPIC_OTA_BROADCAST, 1);
         xEventGroupSetBits(s_evt, MQTT_CONNECTED_BIT);
         mqtt_publisher_announce();
         break;
@@ -85,7 +107,8 @@ static void mqtt_event_handler(void *arg, esp_event_base_t base,
         break;
 
     case MQTT_EVENT_DATA:
-        if (strncmp(event->topic, s_topic_cmd, event->topic_len) == 0) {
+        if (strncmp(event->topic, s_topic_cmd, event->topic_len) == 0 ||
+            strncmp(event->topic, TOPIC_OTA_BROADCAST, event->topic_len) == 0) {
             handle_cmd(event->data, event->data_len);
         }
         break;
@@ -101,9 +124,11 @@ static void mqtt_event_handler(void *arg, esp_event_base_t base,
 
 esp_err_t mqtt_publisher_init(const char *sensor_id,
                                const char *broker_uri,
-                               EventGroupHandle_t evt_group)
+                               EventGroupHandle_t evt_group,
+                               const char *version)
 {
     strncpy(s_sensor_id, sensor_id, sizeof(s_sensor_id) - 1);
+    strncpy(s_firmware_version, version ? version : "", sizeof(s_firmware_version) - 1);
     s_evt = evt_group;
     build_topics();
 
@@ -126,8 +151,10 @@ esp_err_t mqtt_publisher_init(const char *sensor_id,
 void mqtt_publisher_announce(void)
 {
     if (!s_client) return;
-    esp_mqtt_client_publish(s_client, s_topic_announce, "", 0, 1, 0);
-    ESP_LOGI(TAG, "Announced on %s", s_topic_announce);
+    char payload[48];
+    int len = snprintf(payload, sizeof(payload), "{\"version\":\"%s\"}", s_firmware_version);
+    esp_mqtt_client_publish(s_client, s_topic_announce, payload, len, 1, 0);
+    ESP_LOGI(TAG, "Announced on %s (version: %s)", s_topic_announce, s_firmware_version);
 }
 
 void mqtt_publisher_send_rssi(const char *tag_id, int8_t rssi)
@@ -139,3 +166,24 @@ void mqtt_publisher_send_rssi(const char *tag_id, int8_t rssi)
                        "{\"tag_id\":\"%s\",\"rssi\":%d}", tag_id, (int)rssi);
     esp_mqtt_client_publish(s_client, s_topic_rssi, payload, len, 1, 0);
 }
+
+void mqtt_publisher_send_beacon(const char *type, const char *id, int8_t tx_power, int8_t rssi)
+{
+    if (!s_client) return;
+
+    char payload[128];
+    int len = snprintf(payload, sizeof(payload),
+                       "{\"type\":\"%s\",\"id\":\"%s\",\"tx_power\":%d,\"rssi\":%d}",
+                       type, id, (int)tx_power, (int)rssi);
+    esp_mqtt_client_publish(s_client, s_topic_rssi, payload, len, 1, 0);
+}
+
+void mqtt_publisher_send_ota_status(const char *status, const char *version)
+{
+    if (!s_client) return;
+
+    char payload[96];
+    int len = snprintf(payload, sizeof(payload),
+                       "{\"status\":\"%s\",\"version\":\"%s\"}", status, version ? version : "");
+    esp_mqtt_client_publish(s_client, s_topic_ota, payload, len, 1, 0);
+}

components/ota_manager/CMakeLists.txt

@@ -0,0 +1,5 @@
+idf_component_register(
+    SRCS "src/ota_manager.c"
+    INCLUDE_DIRS "include"
+    REQUIRES esp_https_ota app_update mqtt_publisher esp_system
+)

components/ota_manager/include/ota_manager.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include "esp_err.h"
+
+/**
+ * Begin an OTA update in a background task.
+ * Applies a MAC-derived jitter delay before downloading so a fleet-wide
+ * trigger staggers reboots instead of dropping all coverage at once.
+ * Reports status via mqtt_publisher_send_ota_status().
+ * On success the device reboots; on failure it stays on the current firmware.
+ */
+esp_err_t ota_manager_start(const char *url, const char *version);

components/ota_manager/src/ota_manager.c

@@ -0,0 +1,84 @@
+#include "ota_manager.h"
+#include "mqtt_publisher.h"
+#include "esp_https_ota.h"
+#include "esp_ota_ops.h"
+#include "esp_mac.h"
+#include "esp_log.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <string.h>
+#include <stdlib.h>
+
+#define TAG "ota_manager"
+
+/* Prevent concurrent OTA attempts */
+static volatile bool s_ota_running = false;
+
+typedef struct {
+    char url[256];
+    char version[32];
+} ota_task_arg_t;
+
+static void ota_task(void *arg)
+{
+    ota_task_arg_t *params = (ota_task_arg_t *)arg;
+
+    /* Spread reboots across up to 60 s using last 3 MAC bytes as seed */
+    uint8_t mac[6];
+    esp_read_mac(mac, ESP_MAC_WIFI_STA);
+    uint32_t jitter_ms = ((uint32_t)(mac[3] ^ mac[4] ^ mac[5])) % 60000;
+    if (jitter_ms > 0) {
+        ESP_LOGI(TAG, "OTA jitter: %lu ms", jitter_ms);
+        mqtt_publisher_send_ota_status("pending", params->version);
+        vTaskDelay(pdMS_TO_TICKS(jitter_ms));
+    }
+
+    ESP_LOGI(TAG, "Starting OTA from %s", params->url);
+    mqtt_publisher_send_ota_status("downloading", params->version);
+
+    esp_http_client_config_t http_cfg = {
+        .url            = params->url,
+        .timeout_ms     = 30000,
+        .keep_alive_enable = true,
+    };
+    esp_https_ota_config_t ota_cfg = {
+        .http_config = &http_cfg,
+    };
+
+    esp_err_t err = esp_https_ota(&ota_cfg);
+    if (err == ESP_OK) {
+        ESP_LOGI(TAG, "OTA succeeded, rebooting");
+        mqtt_publisher_send_ota_status("rebooting", params->version);
+        vTaskDelay(pdMS_TO_TICKS(500)); /* let MQTT publish flush */
+        esp_restart();
+    } else {
+        ESP_LOGE(TAG, "OTA failed: %s", esp_err_to_name(err));
+        mqtt_publisher_send_ota_status("failed", params->version);
+    }
+
+    free(params);
+    s_ota_running = false;
+    vTaskDelete(NULL);
+}
+
+esp_err_t ota_manager_start(const char *url, const char *version)
+{
+    if (s_ota_running) {
+        ESP_LOGW(TAG, "OTA already in progress, ignoring");
+        return ESP_ERR_INVALID_STATE;
+    }
+
+    ota_task_arg_t *params = malloc(sizeof(ota_task_arg_t));
+    if (!params) return ESP_ERR_NO_MEM;
+
+    strncpy(params->url,     url,     sizeof(params->url)     - 1);
+    strncpy(params->version, version ? version : "", sizeof(params->version) - 1);
+
+    s_ota_running = true;
+    if (xTaskCreate(ota_task, "ota_task", 8192, params, 5, NULL) != pdPASS) {
+        free(params);
+        s_ota_running = false;
+        return ESP_FAIL;
+    }
+    return ESP_OK;
+}

components/provisioning/src/provisioning.c

@@ -103,7 +103,7 @@ esp_err_t provisioning_run(void)
 
     network_prov_mgr_config_t config = {
         .scheme                     = network_prov_scheme_ble,
-        .scheme_event_handler       = NETWORK_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BTDM,
+        .scheme_event_handler       = NETWORK_PROV_SCHEME_BLE_EVENT_HANDLER_FREE_BT,
         .network_prov_wifi_conn_cfg = { .wifi_conn_attempts = 3 },
     };
     ESP_ERROR_CHECK(network_prov_mgr_init(config));

deploy_firmware.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+# Upload firmware to localiserd, optionally triggering
+# a fleet-wide OTA push immediately after upload.
+#
+# Usage:
+#   ./deploy_firmware.sh <firmware_path> <version> <localiserd_url> <token> [--ota]
+#
+# Example:
+#   ./deploy_firmware.sh ./build/esp-anchor.bin 1.2.0 http://192.168.1.10:4000 <jwt> --ota
+
+set -euo pipefail
+
+FIRMWARE_PATH="${1:?Usage: $0 <firmware_path> <version> <localiserd_url> <token> [--ota]}"
+VERSION="${2:?}"
+SERVER="${3:?}"
+TOKEN="${4:?}"
+OTA="${5:-}"
+
+if [[ ! -f "$FIRMWARE_PATH" ]]; then
+  echo "ERROR: firmware not found at $FIRMWARE_PATH" >&2
+  exit 1
+fi
+
+SIZE=$(wc -c < "$FIRMWARE_PATH")
+echo "==> Built: $FIRMWARE_PATH ($SIZE bytes)"
+
+# Upload
+echo "==> Uploading version $VERSION to $SERVER..."
+curl -fsS \
+  -H "Authorization: Bearer $TOKEN" \
+  -F "version=$VERSION" \
+  -F "firmware=@$FIRMWARE_PATH;type=application/octet-stream" \
+  "$SERVER/api/firmware" \
+  | jq .
+
+# Fleet OTA
+if [[ "$OTA" == "--ota" ]]; then
+  echo "==> Pushing fleet OTA for version $VERSION..."
+  curl -fsS -X POST \
+    -H "Authorization: Bearer $TOKEN" \
+    -H "Content-Type: application/json" \
+    "$SERVER/api/firmware/$VERSION/ota" \
+    | jq .
+fi
+
+echo "==> Done."

main/CMakeLists.txt

@@ -12,6 +12,9 @@ idf_component_register(
         ble_scanner
         mqtt_publisher
         led_indicator
+        ota_manager
+        app_update
         driver
         esp_driver_gpio
+        esp_coex
 )

main/main.c

@@ -3,6 +3,9 @@
 #include "ble_scanner.h"
 #include "mqtt_publisher.h"
 #include "led_indicator.h"
+#include "ota_manager.h"
+#include "esp_ota_ops.h"
+#include "esp_coexist.h"
 
 #include "esp_wifi.h"
 #include "esp_event.h"
@@ -19,7 +22,7 @@
 
 #define TAG "main"
 
-#define WIFI_CONNECTED_BIT BIT5   /* offset to avoid clashing with mqtt_publisher bits */
+#define WIFI_CONNECTED_BIT BIT8   /* must not clash with mqtt_publisher bits (BIT0-BIT7) */
 
 #define DEFAULT_MQTT_PORT 1883
 #define MDNS_QUERY_TIMEOUT_MS 3000
@@ -73,16 +76,36 @@ static void wifi_event_handler(void *arg, esp_event_base_t base,
     }
 }
 
-static void on_ble_scan_result(const char *tag_id, int8_t rssi)
+static const char *beacon_type_str(ble_beacon_type_t t)
 {
-    mqtt_publisher_send_rssi(tag_id, rssi);
+    switch (t) {
+    case BLE_BEACON_IBEACON:       return "ibeacon";
+    case BLE_BEACON_ALTBEACON:     return "altbeacon";
+    case BLE_BEACON_EDDYSTONE_UID: return "eddystone_uid";
+    case BLE_BEACON_EDDYSTONE_URL: return "eddystone_url";
+    default:                       return "unknown";
+    }
+}
+
+static void on_ble_scan_result(const ble_beacon_t *beacon)
+{
+    mqtt_publisher_send_beacon(beacon_type_str(beacon->type),
+                               beacon->id, beacon->tx_power, beacon->rssi);
 }
 
 static void wifi_init_sta(void)
 {
     esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, wifi_event_handler, NULL);
     esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, wifi_event_handler, NULL);
+
+    esp_netif_t *netif = esp_netif_get_handle_from_ifkey("WIFI_STA_DEF");
+    esp_netif_ip_info_t ip_info = {0};
+    if (netif && esp_netif_get_ip_info(netif, &ip_info) == ESP_OK && ip_info.ip.addr != 0) {
+        ESP_LOGI(TAG, "WiFi already connected (IP: " IPSTR ")", IP2STR(&ip_info.ip));
+        xEventGroupSetBits(s_evt, WIFI_CONNECTED_BIT);
+    } else {
         ESP_ERROR_CHECK(esp_wifi_connect());
+    }
 }
 
 static bool resolve_mqtt_broker_mdns(char *host_out, size_t host_len, uint16_t *port_out)
@@ -199,9 +222,23 @@ void app_main(void)
     snprintf(broker_uri, sizeof(broker_uri), "mqtt://%s:%u", broker_host, broker_port);
 
     // init MQTT
-    ESP_ERROR_CHECK(mqtt_publisher_init(sensor_id, broker_uri, s_evt));
+    const esp_partition_t *running = esp_ota_get_running_partition();
+    esp_app_desc_t app_desc;
+    const char *fw_version = (esp_ota_get_partition_description(running, &app_desc) == ESP_OK)
+                             ? app_desc.version : "unknown";
+    ESP_ERROR_CHECK(mqtt_publisher_init(sensor_id, broker_uri, s_evt, fw_version));
     xEventGroupWaitBits(s_evt, MQTT_CONNECTED_BIT, pdFALSE, pdTRUE, portMAX_DELAY);
 
+    /* Confirm this firmware is healthy so the bootloader won't roll back */
+    esp_ota_img_states_t ota_state;
+    if (esp_ota_get_state_partition(running, &ota_state) == ESP_OK &&
+        ota_state == ESP_OTA_IMG_PENDING_VERIFY) {
+        esp_ota_mark_app_valid_cancel_rollback();
+        ESP_LOGI(TAG, "OTA rollback cancelled - firmware validated");
+    }
+
+    esp_coex_preference_set(ESP_COEX_PREFER_BALANCE);
+
     // init BLE scanner
     ble_scanner_init(on_ble_scan_result);
     ble_scanner_start();
@@ -213,7 +250,8 @@ void app_main(void)
     const EventBits_t cmd_bits =
         MQTT_CALIBRATE_START | MQTT_CALIBRATE_STOP |
         MQTT_SELECTED_BIT    | MQTT_DESELECTED_BIT |
-        MQTT_FACTORY_RESET_BIT | MQTT_RECONFIGURE_SETTINGS_BIT;
+        MQTT_FACTORY_RESET_BIT | MQTT_RECONFIGURE_SETTINGS_BIT |
+        MQTT_OTA_BIT;
 
     bool calibrating = false;
     bool selected    = false;
@@ -242,6 +280,11 @@ void app_main(void)
             selected = false;
             if (!calibrating) led_indicator_set(LED_SCANNING);
         }
+        if (bits & MQTT_OTA_BIT) {
+            const mqtt_ota_data_t *ota = mqtt_publisher_get_ota_data();
+            ESP_LOGI(TAG, "OTA requested: url=%s version=%s", ota->url, ota->version);
+            ota_manager_start(ota->url, ota->version);
+        }
         if (bits & MQTT_FACTORY_RESET_BIT) {
             // factory reset requested - erase NVS and reboot
             ESP_LOGI(TAG, "Factory reset requested");

sdkconfig.defaults

@@ -1,7 +1,18 @@
 CONFIG_BT_ENABLED=y
 CONFIG_BTDM_CTRL_MODE_BLE_ONLY=y
-CONFIG_BT_BLUEDROID_ENABLED=y
-CONFIG_BT_BLE_42_FEATURES_SUPPORTED=y
+CONFIG_BT_NIMBLE_ENABLED=y
+# NimBLE host task pinned to core 0 alongside the BT controller (WiFi stays core 1)
+CONFIG_BT_NIMBLE_PINNED_TO_CORE_0=y
+# Only provisioning needs 1 connection; scanning needs 0
+CONFIG_BT_NIMBLE_MAX_CONNECTIONS=1
+# mbuf pool sized for high-throughput advertisement reports
+CONFIG_BT_NIMBLE_MSYS_1_BLOCK_COUNT=16
+CONFIG_BT_NIMBLE_MSYS_2_BLOCK_SIZE=320
+CONFIG_BT_NIMBLE_MSYS_2_BLOCK_COUNT=6
+CONFIG_BT_NIMBLE_HOST_TASK_STACK_SIZE=4096
+# Advertisement report flow control
+CONFIG_BTDM_BLE_ADV_REPORT_FLOW_CTRL_SUPP=y
+CONFIG_BTDM_BLE_ADV_REPORT_FLOW_CTRL_NUM=100
 
 # WiFi
 CONFIG_ESP_WIFI_STATIC_RX_BUFFER_NUM=10
@@ -20,3 +31,8 @@ CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
 
 # Enable OTA
 CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE=y
+CONFIG_ESP_HTTPS_OTA_ALLOW_HTTP=y
+
+# Factory reset button (GPIO 0 = BOOT button on ESP32 DevKit)
+CONFIG_ANCHOR_RESET_GPIO=0
+CONFIG_ANCHOR_RESET_HOLD_MS=5000