Once the serial port is open, sending data to the embedded controller is just as easy as calling MATLAB’s “fprintf” function. For instance, fprintf (serial_port, strcat (‘2$’, num2str (round (angle2)) ...

At a Glance MATLAB can be used for circuit analysis, signal processing, control system design, FEA, kinematics, & thermal simulations. It supports several embedded platforms & microcontrollers, ...

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.

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.