cpp serial print override always in same place

The Serial.print() function in the Arduino programming language (based on C++) is used to send data over the serial port for debugging or communication purposes. By default, it prints the data to the serial monitor in the Arduino IDE.

If you want to override the default behavior of Serial.print() and print the data to a different location, you can modify the write() function of the HardwareSerial class, which is the underlying class used by Serial. Here are the steps to do that:

Step 1: Locate the HardwareSerial.cpp file

The HardwareSerial class is defined in the HardwareSerial.cpp file, which is located in the cores folder of the Arduino installation directory. Open this file in your preferred code editor.

Step 2: Find the write() function

Inside the HardwareSerial.cpp file, search for the write() function. This function is responsible for sending data over the serial port.

Step 3: Modify the write() function

Inside the write() function, you can add your own code to override the default behavior of Serial.print(). You can write the data to a different location, such as a different serial port, a file, or a network connection.

Step #### Explanation of Overriding the Serial Print Function in C++

#include <Arduino.h>

class CustomSerial : public Stream {
public:
  size_t write(uint8_t c) override {
    // Custom behavior
    return 1;
  }
};

CustomSerial customSerial;

void setup() {
  customSerial.begin(9600);
}

void loop() {
  customSerial.print("Hello, world!");
  delay(1000);
}
  1. Include Arduino Library:

  2. The #include <Arduino.h> directive includes the Arduino library, which provides the necessary functionality for working with Arduino boards and peripherals.

  3. CustomSerial Class Definition:

  4. The CustomSerial class is defined, which publicly inherits from the Stream class. This allows CustomSerial to inherit the properties and methods of the Stream class.

  5. Override the write() Function:

  6. The write() function is overridden in the CustomSerial class. This function is a virtual function inherited from the Stream class and is used for writing data. The override keyword indicates that this function is intended to override a virtual function in the base class.

  7. Custom Behavior in write() Function:

  8. Inside the overridden write() function, custom behavior can be implemented to handle the writing of data to the serial interface. In this example, the function simply returns 1, but custom behavior can be added as per the requirements.

  9. CustomSerial Object Creation:

  10. An instance of the CustomSerial class named customSerial is created.

  11. Setup Function:

  12. The setup() function is called when the program starts. In this function, the begin() method is called on the customSerial object to initialize the serial communication at a baud rate of 9600.

  13. Loop Function:

  14. The loop() function is called repeatedly after the setup() function. In this function, the print() method is called on the customSerial object to print "Hello, world!" to the serial interface, followed by a delay of 1000 milliseconds.

This code demonstrates how to override the print() function of the serial interface in C++ for use with Arduino.