c语言 串口通讯
本文主要内容包含:
1.接收串口数据程序的编程逻辑示意图;
2.接收串口数据程序要用到的通用函数模块(可直接引用,无需更改);
3.接收串口数据程序的示例。
1.接收串口数据程序的编程逻辑示意图:
2.与串口有关的函数模块及数组(可直接引用到自己的程序中):
- <span style="font-size:18px;">//设置波特率函数会用到的数组
- int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300,
- B38400, B19200, B9600, B4800, B2400, B1200, B300, };
- int name_arr[] = {38400, 19200, 9600, 4800, 2400, 1200, 300,
- 38400, 19200, 9600, 4800, 2400, 1200, 300, };
- <span style="font-size:18px;">int OpenDev(char *Dev) //打开串口
- {
- int fd = open(Dev,O_RDWR | O_NOCTTY | O_NONBLOCK);
- if(-1 == fd)
- {
- perror("Can't Open Serial Port");
- return -1;
- }
- else
- {
- printf("Open com success!!!!!!!!!!!");
- return fd;
- }
- }
- <span style="font-size:18px;">void set_speed(int fd, int speed) //设置波特率
- {
- int i;
- int status;
- struct termios Opt;
- tcgetattr(fd, &Opt);
- for ( i= 0; i < sizeof(speed_arr) / sizeof(int); i++)
- {
- if (speed == name_arr[i])
- {
- tcflush(fd, TCIOFLUSH);
- cfsetispeed(&Opt, speed_arr[i]);
- cfsetospeed(&Opt, speed_arr[i]);
- status = tcsetattr(fd, TCSANOW, &Opt);
- if (status != 0)
- perror("tcsetattr fd1");
- return;
- }
- tcflush(fd,TCIOFLUSH);
- }
- }
- <span style="font-size:18px;">int set_Parity(int fd,int databits,int stopbits,int parity) //设置数据位、奇偶位、停止位等
- {
- struct termios options;
- if ( tcgetattr( fd,&options) != 0)
- {
- perror("SetupSerial 1");
- return(0);
- }
- bzero(&options,sizeof(options));
- options.c_cflag |= CLOCAL | CREAD;
- options.c_cflag &= ~CSIZE;
- switch (databits) /*设置数据位*/
- {
- case 7:
- options.c_cflag |= CS7;
- break;
- case 8:
- options.c_cflag |= CS8;
- break;
- default:
- fprintf(stderr,"Unsupported data size\n");
- return (0);
- }
- switch (parity)/*设置校验位*/
- {
- case 'n':
- case 'N':
- options.c_cflag &= ~PARENB;
- //options.c_iflag &= ~INPCK;
- break;
- case 'o':
- case 'O':
- options.c_cflag |= (PARODD | PARENB);
- options.c_iflag |= (INPCK | ISTRIP);
- break;
- case 'e':
- case 'E':
- options.c_cflag |= PARENB;
- options.c_cflag &= ~PARODD;
- options.c_iflag |= (INPCK | ISTRIP);
- break;
- case 'S':
- case 's':
- options.c_cflag &= ~PARENB;
- options.c_cflag &= ~CSTOPB;
- break;
- default:
- fprintf(stderr,"Unsupported parity\n");
- return (0);
- }
- switch (stopbits)/*设置停止位*/
- {
- case 1:
- options.c_cflag &= ~CSTOPB;
- break;
- case 2:
- options.c_cflag |= CSTOPB;
- break;
- default:
- fprintf(stderr,"Unsupported stop bits\n");
- return (FALSE);
- }
- if (parity != 'n')
- options.c_iflag |= INPCK;
- options.c_cc[VTIME] = 0;
- options.c_cc[VMIN] = 0;
- tcflush(fd,TCIFLUSH);
- if (tcsetattr(fd,TCSANOW,&options) != 0)
- {
- perror("SetupSerial 3");
- return (0);
- }
- return (1);
- }
3.示例:
- <span style="font-size:18px;">#include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #include
- #define TRUE 1
- #define FALSE 0
- int analysis(char *buff);
- int OpenDev(char *Dev);
- void set_speed(int fd, int speed);
- int set_Parity(int fd,int databits,int stopbits,int parity);
- int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300, B38400, B19200, B9600, B4800, B2400, B1200, B300, };
- int name_arr[] = {38400, 19200, 9600, 4800, 2400, 1200, 300, 38400, 19200, 9600, 4800, 2400, 1200, 300, };
- int OpenDev(char *Dev)
- {
- int fd = open(Dev,O_RDWR | O_NOCTTY | O_NONBLOCK);
- if(-1 == fd)
- {
- perror("Can't Open Serial Port");
- return -1;
- }
- else
- {
- printf("Open com success!!!!!!!!!!!");
- return fd;
- }
- }
- void set_speed(int fd, int speed)
- {
- int i;
- int status;
- struct termios Opt;
- tcgetattr(fd, &Opt);
- for ( i= 0; i < sizeof(speed_arr) / sizeof(int); i++)
- {
- if (speed == name_arr[i])
- {
- tcflush(fd, TCIOFLUSH);
- cfsetispeed(&Opt, speed_arr[i]);
- cfsetospeed(&Opt, speed_arr[i]);
- status = tcsetattr(fd, TCSANOW, &Opt);
- if (status != 0) perror("tcsetattr fd1");
- return;
- }
- tcflush(fd,TCIOFLUSH);
- }
- }
- int set_Parity(int fd,int databits,int stopbits,int parity)
- {
- struct termios options;
- if ( tcgetattr( fd,&options) != 0)
- {
- perror("SetupSerial 1");
- return(FALSE);
- }
- bzero(&options,sizeof(options));
- options.c_cflag |= CLOCAL | CREAD;
- options.c_cflag &= ~CSIZE;
- switch (databits)
- {
- case 7:
- options.c_cflag |= CS7;
- break;
- case 8:
- options.c_cflag |= CS8;
- break;
- default: fprintf(stderr,"Unsupported data size\n");
- return (FALSE);
- }
- switch (parity)
- {
- case 'n':
- case 'N':
- options.c_cflag &= ~PARENB;
- options.c_iflag &= ~INPCK;
- break;
- case 'o':
- case 'O':
- options.c_cflag |= (PARODD | PARENB);
- options.c_iflag |= (INPCK | ISTRIP);
- break;
- case 'e':
- case 'E':
- options.c_cflag |= PARENB;
- options.c_cflag &= ~PARODD;
- options.c_iflag |= (INPCK | ISTRIP);
- break;
- case 'S':
- case 's':
- options.c_cflag &= ~PARENB;
- options.c_cflag &= ~CSTOPB;
- break;
- default: fprintf(stderr,"Unsupported parity\n");
- return (FALSE);
- }
- switch (stopbits)
- {
- case 1:
- options.c_cflag &= ~CSTOPB;
- break;
- case 2:
- options.c_cflag |= CSTOPB;
- break;
- default: fprintf(stderr,"Unsupported stop bits\n");
- return (FALSE);
- }
- if (parity != 'n')
- options.c_iflag |= INPCK;
- options.c_cc[VTIME] = 0;
- options.c_cc[VMIN] = 0;
- tcflush(fd,TCIFLUSH);
- if (tcsetattr(fd,TCSANOW,&options) != 0)
- {
- perror("SetupSerial 3");
- return (FALSE);
- }
- return (TRUE);
- }
- int analysis (char *buff)
- {
- int i;
- char *p;
- p=buff;
- for(i=0;i<255,i++)
- {
- printf("%s ",p[i]);
- }
- return 0;
- }
- void main(void)
- {
- int fd;
- int nread;
- char buff[255];
- char *dev_name = "/dev/ttymxc4";//根据实际情况选择串口
- while(1)
- {
- fd = OpenDev(dev_name); //打开串口
- if(fd>0)
- set_speed(fd,9600); //设置波特率
- else
- {
- printf("Can't Open Serial Port!\n");
- sleep(1);
- continue;
- }
- break;
- }
- if(set_Parity(fd,8,1,'N')==FALSE) //设置校验位
- {
- printf("Set Parity Error\n");
- exit(1);
- }
- while(1)
- {
- sleep(3);
- nread = read(fd,buff,sizeof(buff));
- if((nread>0))
- {
- printf("Success!\n");
- }
- analysis(buff);
- }
- }