The small Arduino UNO terminal sender program is made to transfer Serial terminal data to the ESP32 Serial terminal only. This sketch is also attached herewith for ready references.

Most Arduino users will know about the Serial Monitor built into the IDE (available from the ‘Tools’ menu, or with keyboard shortcut Ctrl+Shft+M). This is a simple serial terminal that displays any ...

While the Arduino family of boards connect to your computer using a USB virtual serial port, the ATmega ones have an actual serial connection on-board.

DIN Rail Mount Pinout Breakout Terminal Block Module for Arduino UNO R3 HiLetgo 5pcs RS232 to TTL Converter Module COM Serial Port Board MAX3232 MAX232CSE ...

Arduino Nano screw terminal adapter “With a finished project, you’re likely to make permanent connections to your Nano by soldering it.