MycilaWebSerial is a Serial Monitor for ESP32 that can be accessed remotely via a web browser. Webpage is stored in program memory of the microcontroller.

This library is based on the UI from asjdf/WebSerialLite (and this part falls under GPL v3).

• Simplified callbacks
• Fixed UI
• Fixed Web Socket auto reconnect
• Fixed Web Socket client cleanup (See WEBSERIAL_MAX_WS_CLIENTS)
• Command history (up/down arrow keys) saved in local storage
• Support logo and fallback to title if not found.
• Arduino 3 / ESP-IDF 5.1 Compatibility
• Improved performance: can stream up to 20 lines per second is possible
• Support custom page with WSL_CUSTOM_PAGE

To add a logo, add a handler for /logo to serve your logo in the image format you want, gzipped or not. You can use the ESP32 embedding mechanism.

DemoVideo

• Works on WebSockets
• Realtime logging
• Any number of Serial Monitors can be opened on the browser
• Uses Async Webserver for better performance
• Light weight (<3k)
• Timestamp
• Event driven

• ESP32Async/ESPAsyncWebServer

  WebSerial webSerial;

  webSerial.onMessage([](const std::string& msg) { Serial.println(msg.c_str()); });
  webSerial.begin(server);

  webSerial.print("foo bar baz");

If you need line buffering to use print(c), printf, write(c), etc:

  WebSerial webSerial;

  webSerial.onMessage([](const std::string& msg) { Serial.println(msg.c_str()); });
  webSerial.begin(server);

  webSerial.setBuffer(100); // initial buffer size

  webSerial.printf("Line 1: %" PRIu32 "\nLine 2: %" PRIu32, count, ESP.getFreeHeap());
  webSerial.println();
  webSerial.print("Line ");
  webSerial.print(3);
  webSerial.println();

WebSerial is a class. It is not a static instance anymore. This allows you to initialize it only when needed in order to save memory space:

  WebSerial* webSerial = nullptr;

  void setup() {
    if (shouldEnableWebSerial) {
      webSerial = new WebSerial();
      webSerial->onMessage([](const std::string& msg) { Serial.println(msg.c_str()); });
      webSerial->begin(server);
    }
  }

  void loop() {
    if (webSerial) {
      webSerial->print("foo bar baz");
    }
  }