Linux串口操作的一段代碼

Linux串口操作的一段代碼：

1. /*
2. * termio.c
3. *
4. * Created on: 2011-11-2
5. * Author: jieen
6. */
10. #include <stdio.h> /*標准輸入輸出定義*/
11. #include <stdlib.h> /*標准函數庫定義*/
12. #include <unistd.h> /*Unix 標准函數定義*/
13. #include <sys/types.h>
14. #include <sys/stat.h>
15. #include <fcntl.h> /*文件控制定義*/
16. #include <termios.h> /*PPSIX 終端控制定義*/
17. #include <errno.h> /*錯誤號定義*/
19. #if 0
20. int main(void)
21. {
22. int fd;
23. /*以讀寫方式打開串口*/
24. fd = open( "/dev/ttyS0", O_RDWR);
25. if (-1 == fd)
26. {
27. /* 不能打開串口一*/
28. perror(" 提示錯誤！");
29. }
30. struct termios Opt;
31. tcgetattr(fd, &Opt);
32. printf("speed:%x\n",Opt.c_ispeed);
33. cfsetispeed(&Opt,B115200); /*設置為115200Bps*/
34. cfsetospeed(&Opt,B115200);
35. tcsetattr(fd,TCANOW,&Opt);
37. }
38. #endif
39. /**********************************************************************
40. 代碼說明：使用串口二測試的，發送的數據是字符，
41. 但是沒有發送字符串結束符號，所以接收到後，後面加上了結束符號。
42. 我測試使用的是單片機發送數據到第二個串口，測試通過。
43. **********************************************************************/
44. #define FALSE -1
45. #define TRUE 0
46. /*********************************************************************/
47. int OpenDev(char *Dev)
48. {
49. int fd = open( Dev, O_RDWR ); //| O_NOCTTY | O_NDELAY
50. if (-1 == fd)
51. {
52. perror("Can't Open Serial Port");
53. return -1;
54. }
55. else
56. return fd;
57. }
58. int main(int argc, char **argv)
59. {
60. int fd;
61. int nread;
62. char *dev;
63. char buff[512];
64. dev = (char *)malloc(15);
65. if(argc < 2)
66. {
67. strcpy(dev,"/dev/ttyS0"); //串口一
68. }else
69. {
70. strncpy(dev,argv[1],strlen(argv[1]));
71. }
72. fd = OpenDev(dev);
73. if(fd == -1)
74. exit(EXIT_FAILURE);
75. set_speed(fd,115200);
76. if (set_Parity(fd,8,1,'N') == FALSE) {
77. printf("Set Parity Error\n");
78. exit (0);
79. }
80. while (1) //循環讀取數據
81. {
82. while((nread = read(fd, buff, 512))>0)
83. {
84. printf("\nLen %d\n",nread);
85. buff[nread+1] = '\0';
86. printf( "\n%s", buff);
87. }
88. }
89. //close(fd);
90. // exit (0);
91. }
92. /**
93. *@brief 設置串口通信速率
94. *@param fd 類型 int 打開串口的文件句柄
95. *@param speed 類型 int 串口速度
96. *@return void
97. */
98. void set_speed(int fd, int speed){
99. int i;
100. int status;
101. struct termios Opt;
102. int speed_arr[] = { B38400, B19200, B9600, B4800, B2400, B1200, B300,
103. B38400, B19200, B9600, B4800, B2400, B1200, B300, };
104. int name_arr[] = {38400, 19200, 9600, 4800, 2400, 1200, 300, 38400,
105. 19200, 9600, 4800, 2400, 1200, 300, };
106. tcgetattr(fd, &Opt);
108. for ( i= 0; i < sizeof(speed_arr) / sizeof(int); i++) {
109. if (speed == name_arr[i]) {
110. tcflush(fd, TCIOFLUSH);
111. cfsetispeed(&Opt, speed_arr[i]);
112. cfsetospeed(&Opt, speed_arr[i]);
113. status = tcsetattr(fd, TCSANOW, &Opt);
114. if (status != 0) {
115. perror("tcsetattr fd");
116. return;
117. }
118. tcflush(fd,TCIOFLUSH);
119. }
120. }
121. }
123. int set_Parity(int fd,int databits,int stopbits,int parity)
124. {
125. struct termios options;
126. if ( tcgetattr( fd,&options) != 0) {
127. perror("SetupSerial 1");
128. return(FALSE);
129. }
130. options.c_cflag &= ~CSIZE;
131. switch (databits) /*設置數據位數*/
132. {
133. case 7:
134. options.c_cflag |= CS7;
135. break;
136. case 8:
137. options.c_cflag |= CS8;
138. break;
139. default:
140. fprintf(stderr,"Unsupported data size\n"); return (FALSE);
141. }
142. switch (parity)
143. {
144. case 'n':
145. case 'N':
146. options.c_cflag &= ~PARENB; /* Clear parity enable */
147. options.c_iflag &= ~INPCK; /* Enable parity checking */
148. break;
149. case 'o':
150. case 'O':
151. options.c_cflag |= (PARODD | PARENB); /* 設置為奇效驗*/
152. options.c_iflag |= INPCK; /* Disnable parity checking */
153. break;
154. case 'e':
155. case 'E':
156. options.c_cflag |= PARENB; /* Enable parity */
157. options.c_cflag &= ~PARODD; /* 轉換為偶效驗*/
158. options.c_iflag |= INPCK; /* Disnable parity checking */
159. break;
160. case 'S':
161. case 's': /*as no parity*/
162. options.c_cflag &= ~PARENB;
163. options.c_cflag &= ~CSTOPB;break;
164. default:
165. fprintf(stderr,"Unsupported parity\n");
166. return (FALSE);
167. }
168. /* 設置停止位*/
169. switch (stopbits)
170. {
171. case 1:
172. options.c_cflag &= ~CSTOPB;
173. break;
174. case 2:
175. options.c_cflag |= CSTOPB;
176. break;
177. default:
178. fprintf(stderr,"Unsupported stop bits\n");
179. return (FALSE);
180. }
181. /* Set input parity option */
182. if (parity != 'n')
183. options.c_iflag |= INPCK;
184. tcflush(fd,TCIFLUSH);
185. options.c_cc[VTIME] = 150; /* 設置超時15 seconds*/
186. options.c_cc[VMIN] = 0; /* Update the options and do it NOW */
187. if (tcsetattr(fd,TCSANOW,&options) != 0)
188. {
189. perror("SetupSerial 3");
190. return (FALSE);
191. }
192. return (TRUE);
193. }