In it, he shows an example of using all three ESP32 UARTs from an Arduino program. He calls the third port “secret” although that’s really a misnomer.

Introduction:In Arduino environment, it's convenient to access BT SPP like a serial port and react to the command string sent from the BT serial port. Many Arduino projects have utilized this way ...

It's now Arduino IDE 2.2.0. The new features include Board and Port auto-selection improvements, performance improvements, a smaller download size, and a new CLI (command line interface) version.

Hooking it up is easy—an on-the-go adapter allows the Switch’s USB-C port to connect directly to the Arduino’s Micro-USB port, even supplying power!