头文件：
#ifndef _UART_H_ #define _UART_H_ #include <fcntl.h> #include <termios.h> #include <stdio.h> /* baud rate ============= B600 B1200 B9600 B19200 B38400 B57600 B115200 B230400 B460800 B921600 B1000000 B2000000 B3000000 B4000000 */ /** *@brief set uart port baud rate *@param fd[in] file descriptor of uart port *@param baud[in] baud rate like B9600 *@return none */ void set_baud(int fd, int baud) { int status; struct termios opt; tcgetattr(fd, &opt); tcflush(fd, TCIOFLUSH); cfsetispeed(&opt, baud); cfsetospeed(&opt, baud); status = tcsetattr(fd, TCSANOW, &opt); if (status != 0) { perror("tcsetattr fd1"); return; } tcflush(fd,TCIOFLUSH); } /** *@brief set word length, parity and stop bits *@param fd[in] file descriptor of uart port *@param databits[in] bits of word, valid value 5/6/7/8 *@param stopbits[in] stop bits, valid value 1 or 2 *@param parity[in] parity should be one of None,Even,Odd,Mark,Space */ int set_params(int fd, int databits, int stopbits, int parity) { struct termios options; if ( tcgetattr( fd,&options) != 0) { perror("tcgetattr fail"); return -1; } options.c_iflag = 0; options.c_oflag = 0; //setup data bits options.c_cflag &= ~CSIZE; switch (databits) { case 5: options.c_cflag |= CS5; break; case 6: options.c_cflag |= CS6; break; case 7: options.c_cflag |= CS7; break; case 8: options.c_cflag |= CS8; break; default: return -1; } //parity switch (parity) { case 'n': case 'N': options.c_cflag &= ~PARENB; // Clear parity enable/ options.c_iflag &= ~INPCK; // disable input parity checking/ break; case 'o': case 'O': options.c_cflag |= (PARODD | PARENB); // odd parity checking options.c_iflag |= INPCK; // enable parity checking break; case 'e': case 'E': options.c_cflag |= PARENB; // Enable parity / options.c_cflag &= ~PARODD; // even parity/ options.c_iflag |= INPCK; // enable parity checking / break; case 'M': case 'm': //mark parity/ options.c_cflag |= PARENB | CMSPAR | PARODD; options.c_iflag |= INPCK; // enable parity checking / break; case 'S': case 's': //space parity/ options.c_cflag |= PARENB | CMSPAR; options.c_cflag &= ~PARODD; options.c_iflag |= INPCK; //enable parity checking / break; default: return -1; } // stop bits/ switch (stopbits) { case 1: options.c_cflag &= ~CSTOPB; break; case 2: options.c_cflag |= CSTOPB; break; default: return -1; } // cts rts / //if ( uartID == 1 || uartID == 2 ) // options.c_cflag |= CRTSCTS; //else options.c_cflag &= ~CRTSCTS; options.c_lflag = 0; options.c_cc[VTIME] = 10; options.c_cc[VMIN] = 1; // Set input parity option / tcflush(fd,TCIFLUSH); if (tcsetattr(fd,TCSANOW,&options) != 0) { return -1; } return 0; } speed_t getBaudrate(int baudrate) { switch(baudrate) { case 0: return B0; case 50: return B50; case 75: return B75; case 110: return B110; case 134: return B134; case 150: return B150; case 200: return B200; case 300: return B300; case 600: return B600; case 1200: return B1200; case 1800: return B1800; case 2400: return B2400; case 4800: return B4800; case 9600: return B9600; case 19200: return B19200; case 38400: return B38400; case 57600: return B57600; case 115200: return B115200; case 230400: return B230400; case 460800: return B460800; case 500000: return B500000; case 921600: return B921600; case 1000000: return B1000000; case 1152000: return B1152000; case 1500000: return B1500000; case 2000000: return B2000000; case 2500000: return B2500000; case 3000000: return B3000000; case 3500000: return B3500000; case 4000000: return B4000000; default: return 1152000; } return 1152000; } int uartDevInit(int fd, int uartBaud) { //printf("baud=%d\n", baud); set_baud(fd, getBaudrate(uartBaud)); // uart param / if(set_params(fd, 8, 1, 'n')) { printf("Set uart parameters fail.\n"); return -1; } return 0; } #endif #include<stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include "uart.h" int main() { int fd ; int buf[20]; fd = open("/dev/ttyS4",O_RDWR); uartDevInit(fd,115200); while(1) { read(fd,buf,20); printf("%d\n",buf[0]); } return 0; } 配置串口头文件就好了文章来源: linux 串口测试程序