Serial Port C Example Apr 2026

gcc -o serial_example serial_example.c (you may need sudo for /dev/ttyUSB0 ):

Here’s a practical for serial port communication on Linux/POSIX systems. It demonstrates opening, configuring, reading, writing, and closing a serial port. Serial Port Communication in C – Complete Example #include <stdio.h> // Standard I/O #include <stdlib.h> // Exit functions #include <fcntl.h> // File control (open) #include <termios.h> // Terminal I/O (serial config) #include <unistd.h> // POSIX (read, write, close) #include <string.h> // String operations int serial_open(const char *device, speed_t baud) CS8; // 8-bit chars tty.c_cflag

// Clean up close(fd); return EXIT_SUCCESS; Compile with: serial port c example

void serial_write(int fd, const char *data, size_t len) ssize_t written = write(fd, data, len); if (written < 0) perror("write"); else printf("Wrote %ld bytes\n", written);

// Wait for response char response[256]; serial_read(fd, response, sizeof(response)); gcc -o serial_example serial_example

int fd = serial_open(device, baud); if (fd < 0) return EXIT_FAILURE;

printf("Serial port %s opened at 115200 baud\n", device); // Standard I/O #include &lt

int main() const char *device = "/dev/ttyUSB0"; // Change to your port speed_t baud = B115200;

// Send a command const char *cmd = "AT\r\n"; serial_write(fd, cmd, strlen(cmd));

void serial_read(int fd, char *buffer, size_t buf_size) ssize_t n = read(fd, buffer, buf_size - 1); if (n < 0) perror("read"); else if (n > 0) buffer[n] = '\0'; printf("Read %ld bytes: %s\n", n, buffer);