C++ Serial Port Connection

// serial_posix.cpp
#include <cstring>
#include <errno.h>
#include <fcntl.h>
#include <iostream>
#include <termios.h>
#include <unistd.h>
using namespace std;

// Function to open the serial port
int openSerialPort(const char* portname)
{
    int fd = open(portname, O_RDWR | O_NOCTTY | O_SYNC);
    if (fd < 0) {
        cerr << "Error opening " << portname << ": "
             << strerror(errno) << endl;
        return -1;
    }
    return fd;
}

// Function to configure the serial port
bool configureSerialPort(int fd, int speed)
{
    struct termios tty;
    if (tcgetattr(fd, &tty) != 0) {
        cerr << "Error from tcgetattr: " << strerror(errno)
             << endl;
        return false;
    }

    cfsetospeed(&tty, speed);
    cfsetispeed(&tty, speed);

    tty.c_cflag
        = (tty.c_cflag & ~CSIZE) | CS8; // 8-bit characters
    tty.c_iflag &= ~IGNBRK; // disable break processing
    tty.c_lflag = 0; // no signaling chars, no echo, no
                     // canonical processing
    tty.c_oflag = 0; // no remapping, no delays
    tty.c_cc[VMIN] = 0; // read doesn't block
    tty.c_cc[VTIME] = 5; // 0.5 seconds read timeout

    tty.c_iflag &= ~(IXON | IXOFF
                     | IXANY); // shut off xon/xoff ctrl

    tty.c_cflag
        |= (CLOCAL | CREAD); // ignore modem controls,
                             // enable reading
    tty.c_cflag &= ~(PARENB | PARODD); // shut off parity
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if (tcsetattr(fd, TCSANOW, &tty) != 0) {
        cerr << "Error from tcsetattr: " << strerror(errno)
             << endl;
        return false;
    }
    return true;
}

// Function to read data from the serial port
int readFromSerialPort(int fd, char* buffer, size_t size)
{
    return read(fd, buffer, size);
}

// Function to write data to the serial port
int writeToSerialPort(int fd, const char* buffer,
                      size_t size)
{
    return write(fd, buffer, size);
}

// Function to close the serial port
void closeSerialPort(int fd) { close(fd); }

int main()
{
    // Replace with your serial port name
    const char* portname = "/dev/ttyS1";
    int fd = openSerialPort(portname);
    if (fd < 0)
        return 1;

    if (!configureSerialPort(fd, B9600)) {
        closeSerialPort(fd);
        return 1;
    }

    const char* message = "Hello, Serial Port!";
    if (writeToSerialPort(fd, message, strlen(message))
        < 0) {
        cerr << "Error writing to serial port: "
             << strerror(errno) << endl;
    }

    char buffer[100];
    int n = readFromSerialPort(fd, buffer, sizeof(buffer));
    if (n < 0) {
        cerr << "Error reading from serial port: "
             << strerror(errno) << endl;
    }
    else {
        cout << "Read from serial port: "
             << std::string(buffer, n) << endl;
    }

    closeSerialPort(fd);
    return 0;
}

// This code is contributed by Susobhan Akhuli

//
#include <boost/asio.hpp>
#include <iostream>

using namespace std;
using namespace boost;

// Function to configure the serial port
void configureSerialPort(asio::serial_port& serial,
                         const string& portname,
                         unsigned int baud_rate)
{
    // Open the specified serial port
    serial.open(portname);
    // Set the baud rate
    serial.set_option(
        asio::serial_port_base::baud_rate(baud_rate));
}

// Function to read data from the serial port
string readFromSerialPort(asio::serial_port& serial)
{
    char buffer[100]; // Buffer to store incoming data
    system::error_code ec;
    // Read data from the serial port
    size_t len
        = asio::read(serial, asio::buffer(buffer), ec);
    if (ec) {
        cerr << "Error reading from serial port: "
             << ec.message() << endl;
        return "";
    }
    // Return the read data as a string
    return string(buffer, len);
}

// Function to write data to the serial port
void writeToSerialPort(asio::serial_port& serial,
                       const string& message)
{
    system::error_code ec;
    // Write data to the serial port
    asio::write(serial, asio::buffer(message), ec);
    if (ec) {
        cerr << "Error writing to serial port: "
             << ec.message() << endl;
    }
}

int main()
{
    asio::io_service io; // Create an IO service
    // Create a serial port object
    asio::serial_port serial(io);

    try {
        // Configure the serial port (replace with your port
        // name)
        configureSerialPort(serial, "/dev/ttyS1", 9600);
    }
    catch (const exception& e) {
        cerr << "Error configuring serial port: "
             << e.what() << endl;
        return 1;
    }

    string message = "Hello, Serial Port!";

    // Write the message to the serial port
    writeToSerialPort(serial, message);
    cout << "Message sent: " << message << endl;

    // Read the response from the server
    string response = readFromSerialPort(serial);
    if (!response.empty()) {
        cout << "Response received: " << response << endl;
    }

    serial.close(); // Close the serial port
    return 0;
}

// This code is contributed by Susobhan Akhuli