While looking into adding a serial port I found the Serial2.ino C:\Heltec ESP32\Heltec_ESP32-master\Heltec_ESP32-master\examples\ESP32\Serial2
The ino file shows:
Serial1.begin(115200, SERIAL_8N1, 2, 17);
Serial2.begin(115200, SERIAL_8N1, 22, 23);
Yet the ESP32 V3 has U0RXD on pin 50 and U0TXD on pin 49 according to the schematic
The bottom of the device shows pins with numbers and names that do not match the schematic
pin JP2-5 shows RX on the schematic is pin 44 which is U0RXD of the ESP32S3 on pin 50
pin JP2-6 shows TX on the schematic is pin 43 which is U0TXD of the ESP32S3 on pin 49
I found JP3-5 - 46 which is GPIO46 and 45 which is GPIO45 of the ESP32S3 according to the schematic so Serial2.begin(115200, SERIAL_8N1, 45, 46); with pin 45 as RX and pin 46 as TX?
Thanks
ESP32 V3.2 Serial2.ino and schematics
in general with the ESP32 family you can use any available GPIO pins for serial IO, SPI, I2C, etc
check the pin map of the specific module to see what is used for OLED, LoRa moulde, LEDs, etc and what is generally available, e.g. WiFi LoRa 32(V3), ESP32S3