We also provide a firmware for ESP32-S2 or S3 which acts as a USB - UART/JTAG bridge: https://github.com/espressif/esp-usb-bridge

Sorry if I ask it here (maybe it is better if I open a new discussion?).

On the FTDI, I can set a serial number and this is not only set on the USB-controller-device (in the device manager), but also in the serial-port-device as instance ID.

FTDI:
FTDIBUS\VID_0403+PID_6011+SERIALNUMBER0000円

ESP32:
USB\VID_303A&PID_1001&MI_008円&3A0D5B63&0&0000

Where is this instance id generated? I can't find where in the code, this id is created. I would like to always have the same id and with the USB serial number. Because windows creates a new COM-number for each of this instance id.

Hi @igrr

I've also got the same issue. I've created a custom board with only the USB-D+ connected to GPIO20 and USB-D- connected to GPIO19. That is, I only have available the on-board USB-to-UART bridge.

I'm also able to upload the sketches, but not to use the Serial port for communications.

How did you finally solve it?

I am trying to understand the serial comms from two sides, in the ESP32-S3 and at the PC.

At the ESP32-S3 end
Serial Comms on four interfaces:

• Onboard USB connections

1. USB (direct to ESP32-S3 pins)
2. UART( via FTDI to Tx,Rx pins)

• Pin connections

1. Serial1(HardwareSerial) (to available GPIO)
2. Serial2(HardwareSerial) (to available GPIO)

In an Arduino program:

1. Serial.begin() refers to the UART pins Tx, Rx
2. Serial1.begin() refers to HardwareSerial Serial1(Baud Rate1, Data Protocol1, TxD1 pin, RxD1 pin);
3. Serial2.begin() refers to HardwareSerial Serial2(Baud Rate2, Data Protocol2, TxD2 pin, RxD2 pin);
4. USBSerial.begin(); USB.begin(); refers to the USBCDC USBSerial to the ESP-S3 USB pins

So I can write/read program data to three serial ports - Serial, Serial1, and Serial2.
I can write/read debug messages to the (CDC) serial port USBSerial.

At the PC end
If I plug both the USB and the UART cables into the PC, they present as two separate serial ports, say COMxx (USB), COMyy(UART).
COMxx is selected in the Arduino IDE and the two settings (USB CDC On Boot -> Enabled, Upload Mode -> UART0 / Hardware CDC) mean that the debug messages are received in the IDE.
(But I cannot use COMxx for JTAG debug in this mode.)
Serial data to/from COMyy can be monitored using another Serial Terminal program (e.g. YAT)

Have I understood this correctly?

USBCDC USBSerial;
HardwareSerial Serial1(1);
HardwareSerial Serial2(2);
void setup() {
 Serial.begin(115200)
 Serial1.begin(115200 ...);
 Serial2.begin(115200 ...);
 USBSerial.begin(115200);
 USB.begin();
}
void loop() {
...
 Serial.println("TxRx data");
...
 USBSerial.println("debug message");
...
}

Thankyou for yoyr help.