ESP32-S3 Use of both USBs as Serial out

Other Hardware 3rd Party Boards
1

Hello

I fiddle to figure out how I can use both USB as Output

I have no success. Any clue how to do it. Seems easy but no.

My Board is the ESP32-S3-DevKidC-1

2

With the ESP32-S3-DevKitC-1 board, one of the two USB ports is connected to a USB-to-TTL converter, while the second port connects directly to the microcontroller, leveraging the ESP32's ability to act as a host.

When you enable USB CDC on Boot, Serial0 is connected to the converter, while Serial or SerialUSB becomes the CDC device.

I usually set the board options like this:

  • USB CDC on boot → true
  • USB mode → Hardware CDC and JTAG
  • JTAG adapter → Integrated USB JTAG
3

this works now no 115200 speed for me

#include <Arduino.h>

#include <USB.h>




// 1. Native USB-CDC (erscheint als COM-Port im PC)

USBCDC USBSerial;




// 2. Echter Hardware-UART auf GPIO43 (TX) + GPIO44 (RX)

HardwareSerial ExtSerial(2);   // UART2 → frei auf beliebige Pins legen




void setup() {

  // ───── Native USB für Debug (PlatformIO Monitor) ─────

  USB.begin();

  USBSerial.begin(115200);

  while (!USBSerial) { delay(10); }




  delay(10000);




  // ───── Externer UART auf GPIO43/44 mit deiner funktionierenden Baudrate ─────

  ExtSerial.begin(57600, SERIAL_8N1, 44, 43);   // RX=44, TX=43




  delay(500);




  // Beide Ports begrüßen

  USBSerial.println("\n" "==========================================");

  USBSerial.println("   ESP32-S3 DUAL SERIAL – LÄUFT!");

  USBSerial.println("   USB-CDC → dieser Monitor");

  USBSerial.println("   GPIO43 (TX) + GPIO44 (RX) → 9600 Baud");

  USBSerial.println("==========================================\n");




  ExtSerial.println("Hallo vom echten UART auf GPIO43/44!");

  ExtSerial.println("Das siehst du nur am externen Adapter (9600 Baud)");

}




void loop() {

  static uint32_t last = 0;

  if (millis() - last >= 2000) {

    last = millis();




    // ───── Ausgabe auf BEIDEN Ports gleichzeitig ─────

    String msg = "Dual-Alive: " + String(millis()) + 

                 " ms | Heap: " + String(ESP.getFreeHeap());




    USBSerial.println(msg);         // → PlatformIO Monitor

    ExtSerial.println(msg);         // → GPIO43/44 (9600 Baud)




    // Extra Lebenszeichen nur auf externem Port

    ExtSerial.println("<<< Nur auf GPIO43/44 sichtbar >>>");

  }




  // ───── Loopback: was an GPIO44 reinkommt → auf USB ausgeben ─────

  if (ExtSerial.available()) {

    while (ExtSerial.available()) {

      char c = ExtSerial.read();

      USBSerial.write(c);

    }

    USBSerial.println();

  }




  // ───── Optional: was du in PlatformIO eingibst → an externen Port weiterleiten ─────

  if (USBSerial.available()) {

    while (USBSerial.available()) {

      char c = USBSerial.read();

      ExtSerial.write(c);

    }

  }

}