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.

Although a “CommsLink” module providing an RS-232 port was available back in the day, it’s become hard to find, inspiring [James] to design a completely new module based on an Arduino Nano.

That's why laptops with a true RS232 serial port are at a premium for certain applications.<BR><BR>There are *some* USB-Serial bridges that are better than others. Most only understand a subset of ...

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 ...