- websocket client on ESP32

- telemetry protocol builder
- server-side message handling
- database migrations
- telemetry persistence

esp32/main/ws.cpp

@@ -0,0 +1,82 @@
+#include "ws.h"
+#include "esp_websocket_client.h"
+#include "esp_log.h"
+#include <string.h>
+#include "sdkconfig.h"
+
+static const char* TAG = "WS";
+
+static esp_websocket_client_handle_t client = nullptr;
+static bool connected = false;
+
+static void ws_event_handler(void *handler_args,
+                             esp_event_base_t base,
+                             int32_t event_id,
+                             void *event_data)
+{
+    switch (event_id) {
+
+    case WEBSOCKET_EVENT_CONNECTED:
+        connected = true;
+        ESP_LOGI(TAG, "Connected");
+        break;
+
+    case WEBSOCKET_EVENT_DISCONNECTED:
+        connected = false;
+        ESP_LOGI(TAG, "Disconnected");
+        break;
+
+    case WEBSOCKET_EVENT_ERROR:
+        connected = false;
+        ESP_LOGE(TAG, "Error");
+        break;
+
+    case WEBSOCKET_EVENT_DATA: {
+            auto *data = (esp_websocket_event_data_t *)event_data;
+            ESP_LOGI(TAG, "Recv: %.*s", data->data_len, (char*)data->data_ptr);
+            break;
+    }
+    }
+}
+
+void ws_init(const char* uri)
+{
+    esp_websocket_client_config_t config = {};
+    config.uri = uri;
+    config.reconnect_timeout_ms = 5000;
+    config.network_timeout_ms = 5000;
+
+    client = esp_websocket_client_init(&config);
+    esp_websocket_register_events(client, WEBSOCKET_EVENT_ANY, ws_event_handler, NULL);
+}
+
+void ws_start()
+{
+    if (client) {
+        esp_websocket_client_start(client);
+    }
+}
+
+bool ws_is_connected()
+{
+    return connected;
+}
+
+void ws_send(const char* data)
+{
+    if (connected && client) {
+        esp_websocket_client_send_text(client, data, strlen(data), portMAX_DELAY);
+    }
+}
+
+void ws_go()
+{
+    char uri[128];
+
+    snprintf(uri, sizeof(uri),
+             "ws://%s:%d/ws",
+             CONFIG_SERVER_HOST,
+             CONFIG_SERVER_PORT);
+    ws_init(uri);
+    ws_start();
+}