How do I physically press a keyboard and move a mouse with an arduino or other development board?

If you want to simulate a keyboard and mouse, it is recommended to use the Arduino do development board, which is very convenient to simulate a keyboard and mouse, and the arduino library functions support it directly. The Arduino UNO does not support an analog keyboard.

Can a computer send commands to ARDUINO in real time with a serial port connection for relative operation? So you can randomly call commands to control the behavior of ARDUINO? Does that work with the mouse? So how do we do that?

Yes, you can send commands to the Arduino via a serial port connection and have it do what it needs to do to communicate with your computer in real time. You can write programs or scripts on your computer that use a serial port library to communicate with the Arduino and send commands to control the behavior of the Arduino.

For the mouse, you can use a similar method to control it. Arduino can use a similar library to simulate the behavior of a mouse and receive instructions from the computer through the serial port to do so.

Here is a basic example of how to control a mouse using Arduino and a serial port library:

#include 
void setup() {
  Serial.begin(9600);
}

void loop() {
  if (Serial.available() > 0) {
    char command = Serial.read();
    switch (command) {
      case 'u':
        Mouse.move(0, -10);
        break;
      case 'd':
        Mouse.move(0, 10);
        break;
      case 'l':
        Mouse.move(-10, 0);
        break;
      case 'r':
        Mouse.move(10, 0);
        break;
      case 'p':
        Mouse.press();
        break;
      case 'r':
        Mouse.release();
        break;
    }
  }
}

The above code demonstrates how to simulate the behavior of a Mouse using the Arduino and mouse.h libraries. In the setup() function, the serial port is initialized and set to 9600 baud. In the loop() function, the command is received by checking the serial port for data and using the Mouse.h library to perform the appropriate action. For example, when a character 'u' is received, the mouse will move up 10 pixels, and when a character 'p' is received, the mouse will press the left button.

On your computer, you can use a serial terminal program to send commands to the Arduino, such as PuTTY or TeraTerm. In terminal programs, you can type the characters 'u', 'd', 'l', 'r', etc., to control the movement of the mouse, or the characters 'p' and 'r' to simulate the mouse pressing and releasing the left button.

Of course, the exact implementation depends on the programming language and hardware device you're using, but the basic idea is similar.

Refer to GPT and own ideas, realize the Arduino drive keyboard need to do the following steps:

1 Connect the hardware: Connect the Arduino to the computer and connect the keyboard circuit to the digital output pins of the Arduino.

2 Write code: Write Arduino code to output the key signal on the digital output pin. You can use the Keyboard.h library, which allows you to simulate Keyboard keystrokes. For example, you can simulate pressing and releasing keys using the Keyboard.press() and Keyboard.release() functions.

3 Drive Arduino: You need to write a script or application that sends commands to the Arduino via a serial port connection to control its behavior. You can use the Serial library, which allows you to communicate serial ports between your computer and the Arduino. For example, you can use the Serial.write() function to send instructions to Arduino and the Serial.read() function to read the data returned from Arduino.
As for the choice of development board, MEGA2560 is a good choice because it has enough digital output pins to independently control each key. Other optional development boards include Arduino UNO and Arduino Leonardo, among others.

Finally, in order to integrate a game script written in C++ or an easy language with the Arduino driver, you need some way to connect the two. You can use Python or another programming language to write a mediation program that connects the game script to the Arduino driver, or you can control the Arduino directly from the game script using serial communication. How you do this depends on the language and specific requirements of your game script and Arduino driver.