feat: Add v0.3 OTA updates — dual partition, esp-ota tool, rollback

Dual OTA partition table (ota_0/ota_1, 1920 KB each) on 4MB flash.
Firmware gains OTA command, LED_OTA double-blink, version in STATUS,
and automatic rollback validation. Pi-side esp-ota tool serves firmware
via HTTP and orchestrates the update flow. esp-fleet gains ota subcommand.

get-started/csi_recv_router/main/app_main.c

@@ -30,6 +30,9 @@
 #include "esp_now.h"
 #include "esp_timer.h"
 #include "esp_task_wdt.h"
+#include "esp_ota_ops.h"
+#include "esp_https_ota.h"
+#include "esp_http_client.h"
 #include "driver/gpio.h"
 #include "mdns.h"
 
@@ -65,6 +68,7 @@ typedef enum {
     LED_SLOW_BLINK,
     LED_FAST_BLINK,
     LED_SOLID,
+    LED_OTA,
 } led_mode_t;
 
 /* --- Globals --- */
@@ -74,6 +78,7 @@ static esp_ping_handle_t s_ping_handle = NULL;
 static volatile led_mode_t s_led_mode = LED_OFF;
 static volatile int64_t s_last_csi_time = 0;
 static volatile int64_t s_identify_end_time = 0;
+static volatile bool s_ota_in_progress = false;
 
 /* UDP socket for CSI data transmission */
 static int s_udp_socket = -1;
@@ -181,6 +186,18 @@ static void led_task(void *arg)
             led_on = true;
             vTaskDelay(pdMS_TO_TICKS(200));
             break;
+        case LED_OTA:
+            /* Double-blink: on-off-on-off-pause */
+            gpio_set_level(LED_GPIO, 1);
+            vTaskDelay(pdMS_TO_TICKS(80));
+            gpio_set_level(LED_GPIO, 0);
+            vTaskDelay(pdMS_TO_TICKS(80));
+            gpio_set_level(LED_GPIO, 1);
+            vTaskDelay(pdMS_TO_TICKS(80));
+            gpio_set_level(LED_GPIO, 0);
+            vTaskDelay(pdMS_TO_TICKS(500));
+            led_on = false;
+            break;
         }
     }
 }
@@ -375,6 +392,41 @@ static esp_err_t wifi_ping_router_start(void)
     return ESP_OK;
 }
 
+/* --- OTA --- */
+
+static void ota_task(void *arg)
+{
+    char *url = (char *)arg;
+    ESP_LOGI(TAG, "OTA: downloading from %s", url);
+
+    s_led_mode = LED_OTA;
+
+    esp_http_client_config_t http_cfg = {
+        .url = url,
+        .timeout_ms = 30000,
+    };
+
+    esp_https_ota_config_t ota_cfg = {
+        .http_config = &http_cfg,
+    };
+
+    esp_err_t err = esp_https_ota(&ota_cfg);
+    free(url);
+
+    if (err == ESP_OK) {
+        ESP_LOGI(TAG, "OTA: success, rebooting...");
+        s_led_mode = LED_SOLID;
+        vTaskDelay(pdMS_TO_TICKS(500));
+        esp_restart();
+    } else {
+        ESP_LOGE(TAG, "OTA: failed: %s", esp_err_to_name(err));
+        s_led_mode = LED_SLOW_BLINK;
+        s_ota_in_progress = false;
+    }
+
+    vTaskDelete(NULL);
+}
+
 /* --- Command handler --- */
 
 static void reboot_after_delay(void *arg)
@@ -414,6 +466,8 @@ static int cmd_handle(const char *cmd, char *reply, size_t reply_size)
             rssi = ap.rssi;
         }
 
+        const esp_app_desc_t *app_desc = esp_app_get_description();
+
         char uptime_str[32];
         if (days > 0) {
             snprintf(uptime_str, sizeof(uptime_str), "%dd%dh%dm", days, hours, mins);
@@ -424,9 +478,9 @@ static int cmd_handle(const char *cmd, char *reply, size_t reply_size)
         }
 
         snprintf(reply, reply_size,
-                 "OK STATUS uptime=%s heap=%lu rssi=%d tx_power=%d rate=%d hostname=%s",
+                 "OK STATUS uptime=%s heap=%lu rssi=%d tx_power=%d rate=%d hostname=%s version=%s",
                  uptime_str, (unsigned long)heap, rssi, (int)s_tx_power_dbm,
-                 s_send_frequency, CONFIG_CSI_HOSTNAME);
+                 s_send_frequency, CONFIG_CSI_HOSTNAME, app_desc->version);
         return strlen(reply);
     }
 
@@ -458,6 +512,28 @@ static int cmd_handle(const char *cmd, char *reply, size_t reply_size)
         return strlen(reply);
     }
 
+    /* OTA <url> */
+    if (strncmp(cmd, "OTA ", 4) == 0) {
+        const char *url = cmd + 4;
+        if (strncmp(url, "http://", 7) != 0) {
+            snprintf(reply, reply_size, "ERR OTA url must start with http://");
+            return strlen(reply);
+        }
+        if (s_ota_in_progress) {
+            snprintf(reply, reply_size, "ERR OTA already in progress");
+            return strlen(reply);
+        }
+        char *url_copy = strdup(url);
+        if (!url_copy) {
+            snprintf(reply, reply_size, "ERR OTA out of memory");
+            return strlen(reply);
+        }
+        s_ota_in_progress = true;
+        xTaskCreate(ota_task, "ota_task", 8192, url_copy, 5, NULL);
+        snprintf(reply, reply_size, "OK OTA started");
+        return strlen(reply);
+    }
+
     snprintf(reply, reply_size, "ERR UNKNOWN");
     return strlen(reply);
 }
@@ -563,4 +639,14 @@ void app_main()
     wifi_ping_router_start();
 
     xTaskCreate(cmd_task, "cmd_task", 4096, NULL, 5, NULL);
+
+    /* OTA rollback: mark firmware valid if we got this far */
+    const esp_partition_t *running = esp_ota_get_running_partition();
+    esp_ota_img_states_t ota_state;
+    if (esp_ota_get_state_partition(running, &ota_state) == ESP_OK) {
+        if (ota_state == ESP_OTA_IMG_PENDING_VERIFY) {
+            ESP_LOGI(TAG, "OTA: marking firmware valid (rollback cancelled)");
+            esp_ota_mark_app_valid_cancel_rollback();
+        }
+    }
 }

get-started/csi_recv_router/partitions.csv

@@ -0,0 +1,6 @@
+# Name,   Type, SubType, Offset,   Size
+nvs,      data, nvs,     0x9000,   0x4000
+otadata,  data, ota,     0xd000,   0x2000
+phy_init, data, phy,     0xf000,   0x1000
+ota_0,    app,  ota_0,   0x10000,  0x1E0000
+ota_1,    app,  ota_1,   0x1F0000, 0x1E0000

get-started/csi_recv_router/sdkconfig.defaults

@@ -49,3 +49,16 @@ CONFIG_ESP32_WIFI_DYNAMIC_TX_BUFFER_NUM=32
 #
 CONFIG_ESP32S3_DEFAULT_CPU_FREQ_240=y
 CONFIG_ESP32S3_DEFAULT_CPU_FREQ_MHZ=240
+
+#
+# Flash & Partitions (4MB flash, dual OTA)
+#
+CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y
+CONFIG_PARTITION_TABLE_CUSTOM=y
+CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions.csv"
+
+#
+# OTA Updates
+#
+CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE=y
+CONFIG_ESP_HTTPS_OTA_ALLOW_HTTP=y