一、参考官方代码
1.先从wiringpi库复制一个串口代码
2.查看串口类型
3.将代码修改成ttyS5
4.改完代码后打开串口助手然后编译
代码示例：
#include <stdio.h> #include <string.h> #include <errno.h> #include <pthread.h> #include <wiringPi.h> #include <wiringSerial.h> #include <stdlib.h> #include <unistd.h> int fd; void* Sendhandler() { char *sendbuf; sendbuf = (char *)malloc(32*sizeof(32)); while(1){ memset(sendbuf,'\0',32); scanf("%s",sendbuf); while(*sendbuf){ serialPutchar(fd,*sendbuf++); } } } void* Revhandler() { while(1){ while(serialDataAvail(fd)) { printf("%c",serialGetchar(fd)); fflush(stdout); } } } int main () { int count ; unsigned int nextTime ; pthread_t idSend; pthread_t idRev; if ((fd = serialOpen ("/dev/ttyS5", 115200)) < 0) { fprintf (stderr, "Unable to open serial device: %s\n", strerror (errno)) ; return 1 ; } pthread_create(&idSend,NULL,Sendhandler,NULL); pthread_create(&idRev,NULL,Revhandler,NULL); if (wiringPiSetup () == -1) { fprintf (stdout, "Unable to start wiringPi: %s\n", strerror (errno)) ; return 1 ; } while(1){ sleep(10); } printf ("\n") ; return 0 ; }
二、linux原生串口开发
1.在linux环境下封装串口相关代码
（1）vi uartTool.c
#include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <stdarg.h> #include <string.h> #include <termios.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #include <sys/types.h> #include <sys/stat.h> #include "wiringSerial.h" int myserialOpen (const char *device, const int baud) { struct termios options ; speed_t myBaud ; int status, fd ; switch (baud){ case 9600: myBaud = B9600 ; break ; case 115200: myBaud = B115200 ; break ; } if ((fd = open (device, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK)) == -1) return -1 ; fcntl (fd, F_SETFL, O_RDWR) ; // Get and modify current options: tcgetattr (fd, &options) ; cfmakeraw (&options) ; cfsetispeed (&options, myBaud) ; cfsetospeed (&options, myBaud) ; options.c_cflag |= (CLOCAL | CREAD) ; options.c_cflag &= ~PARENB ; options.c_cflag &= ~CSTOPB ; options.c_cflag &= ~CSIZE ; options.c_cflag |= CS8 ; options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG) ; options.c_oflag &= ~OPOST ; options.c_cc [VMIN] = 0 ; options.c_cc [VTIME] = 100 ; // Ten seconds (100 deciseconds) tcsetattr (fd, TCSANOW, &options) ; ioctl (fd, TIOCMGET, &status); status |= TIOCM_DTR ; status |= TIOCM_RTS ; ioctl (fd, TIOCMSET, &status); usleep (10000) ; // 10mS return fd ; } void serialSendstring (const int fd, const char *s) { int ret; ret = write (fd, s, strlen (s)); if (ret < 0) printf("Serial Puts Error\n"); } int serialGetstring (const int fd, char *buffer) { int n_read; n_read = read(fd, buffer,32); return n_read; }
（2）vi uartTest.c
#include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <stdarg.h> #include <string.h> #include <termios.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <pthread.h> #include "uartTool.h" int fd; void* readSerial() { char buffer[32]; while(1){ memset(buffer,'\0',sizeof(buffer)); serialGetstring(fd, buffer); printf("GET->%s\n",buffer); } } void* sendSerial() { char buffer[32]; while(1){ memset(buffer,'\0',sizeof(buffer)); scanf("%s",buffer); serialSendstring(fd, buffer); } } int main(int argc, char **argv) { char deviceName[32] = {'\0'}; pthread_t readt; pthread_t sendt; if(argc < 2){ printf("uage:%s /dev/ttyS?\n",argv[0]); return -1; } strcpy(deviceName, argv[1]); if( (fd = myserialOpen(deviceName, 115200)) == -1){ printf("open %s error\n",deviceName); return -1; } pthread_create(&readt, NULL, readSerial,NULL); pthread_create(&sendt, NULL, sendSerial,NULL); while(1){sleep(10);} }
（3）vi uartTool.h
int myserialOpen (const char *device, const int baud); void serialSendstring (const int fd, const char *s); int serialGetstring (const int fd, char *buffer);
2.开发板接线和共地图示（根据原理图）
3.编译结果：
串口调试助手图示
