// SPDX-License-Identifier: LGPL-3.0-or-later // Copyright 2016-2025 Hristo Gochkov, Mathieu Carbou, Emil Muratov // // WebSocket example // #include #ifdef ESP32 #include #include #elif defined(ESP8266) #include #include #elif defined(TARGET_RP2040) || defined(TARGET_RP2350) || defined(PICO_RP2040) || defined(PICO_RP2350) #include #include #endif #include static AsyncWebServer server(80); static AsyncWebSocket ws("/ws"); void setup() { Serial.begin(115200); #ifndef CONFIG_IDF_TARGET_ESP32H2 WiFi.mode(WIFI_AP); WiFi.softAP("esp-captive"); #endif // // Run in terminal 1: websocat ws://192.168.4.1/ws => should stream data // Run in terminal 2: websocat ws://192.168.4.1/ws => should stream data // Run in terminal 3: websocat ws://192.168.4.1/ws => should fail: // // To send a message to the WebSocket server: // // echo "Hello!" | websocat ws://192.168.4.1/ws // ws.onEvent([](AsyncWebSocket *server, AsyncWebSocketClient *client, AwsEventType type, void *arg, uint8_t *data, size_t len) { (void)len; if (type == WS_EVT_CONNECT) { ws.textAll("new client connected"); Serial.println("ws connect"); client->setCloseClientOnQueueFull(false); client->ping(); } else if (type == WS_EVT_DISCONNECT) { ws.textAll("client disconnected"); Serial.println("ws disconnect"); } else if (type == WS_EVT_ERROR) { Serial.println("ws error"); } else if (type == WS_EVT_PONG) { Serial.println("ws pong"); } else if (type == WS_EVT_DATA) { AwsFrameInfo *info = (AwsFrameInfo *)arg; Serial.printf("index: %" PRIu64 ", len: %" PRIu64 ", final: %" PRIu8 ", opcode: %" PRIu8 "\n", info->index, info->len, info->final, info->opcode); String msg = ""; if (info->final && info->index == 0 && info->len == len) { if (info->opcode == WS_TEXT) { data[len] = 0; Serial.printf("ws text: %s\n", (char *)data); } } } }); // shows how to prevent a third WS client to connect server.addHandler(&ws).addMiddleware([](AsyncWebServerRequest *request, ArMiddlewareNext next) { // ws.count() is the current count of WS clients: this one is trying to upgrade its HTTP connection if (ws.count() > 1) { // if we have 2 clients or more, prevent the next one to connect request->send(503, "text/plain", "Server is busy"); } else { // process next middleware and at the end the handler next(); } }); server.addHandler(&ws); server.begin(); } static uint32_t lastWS = 0; static uint32_t deltaWS = 100; static uint32_t lastHeap = 0; void loop() { uint32_t now = millis(); if (now - lastWS >= deltaWS) { ws.printfAll("kp%.4f", (10.0 / 3.0)); lastWS = millis(); } if (now - lastHeap >= 2000) { // cleanup disconnected clients or too many clients ws.cleanupClients(); #ifdef ESP32 Serial.printf("Free heap: %" PRIu32 "\n", ESP.getFreeHeap()); #endif lastHeap = now; } }