分类： 嵌入式
2011-12-05 11:17:07
Linux串口测试程序
一个简单串口测试程序，同样也适用于X86平台。程序很简单，运行是通过参数指定程序是发送端还是接收端。接收端运行之后就简单的读取串口数据，打印到stdout。发送端则接受键盘输入，通过串口发送出去。如果直接回车则表示发送完毕，通知接收端退出。
/******************************************************************************
*
* FILENAME:
* testcom.c
*
* DESCRIPTION:
* A utility to read/write serial port
* Usage: testcom
* databits: 5, 6, 7, 8
* parity: 0(None), 1(Odd), 2(Even)
* stopbits: 1, 2
* read_or_write: 0(read), 1(write)
* Example: testcom /dev/ttyS0 9600 8 0 1 1
*
* REVISION(MM/DD/YYYY):
* 03/12/2008 Shengkui Leng (shengkui.leng@advantech.com.cn)
* - Initial version
*
******************************************************************************/
#include
#include
#include
#include
#include
#include
#include
#include
#define MAX_BUF_SIZE 2048
char buf[MAX_BUF_SIZE+2];
#define MY_END_CHAR 0x13
int setup_port(int fd, int baud, int databits, int parity, int stopbits);
int reset_port(int fd);
int read_data(int fd, void *buf, int len);
int write_data(int fd, void *buf, int len);
void print_usage(char *program_name);
int main(int argc, char *argv[])
{
int fd;
int baud;
int len;
int count;
int i;
int databits;
int stopbits;
int parity;
int read_or_write;
if (argc != 7) {
print_usage(argv[0]);
return 1;
}
baud = atoi(argv[2]);
if ((baud < 0) || (baud > 921600)) {
fprintf(stderr, "Invalid baudrate!\n");
return 1;
}
databits = atoi(argv[3]);
if ((databits < 5) || (databits > 8)) {
fprintf(stderr, "Invalid databits!\n");
return 1;
}
parity = atoi(argv[4]);
if ((parity < 0) || (parity > 2)) {
fprintf(stderr, "Invalid parity!\n");
return 1;
}
stopbits = atoi(argv[5]);
if ((stopbits < 1) || (stopbits > 2)) {
fprintf(stderr, "Invalid stopbits!\n");
return 1;
}
read_or_write = atoi(argv[6]);
fd = open(argv[1], O_RDWR, 0);
if (fd < 0) {
fprintf(stderr, "open <%s> error %s\n", argv[1], strerror(errno));
return 1;
}
if (setup_port(fd, baud, databits, parity, stopbits)) {
fprintf(stderr, "setup_port error %s\n", strerror(errno));
close(fd);
return 1;
}
count = 0;
if (read_or_write) {
fprintf(stderr, "Begin to send:\n");
while ( (len = read(0, buf, MAX_BUF_SIZE)) > 0 ) {
if (len == 1) {
buf[0] = MY_END_CHAR;
buf[1] = 0;
write_data(fd, buf, len);
break;
}
/* send a pack */
i = write_data(fd, buf, len);
if (i == 0) {
fprintf(stderr, "Send data error!\n");
break;
}
//count += len;
//fprintf(stderr, "Send %d bytes\n", len);
}
} else {
fprintf(stderr, "Begin to recv:\n");
len = MAX_BUF_SIZE;
while (1) {
/* read a pack */
i = read_data(fd, buf, len);
if (i > 0) {
//count += i;
//fprintf(stderr, "Recv %d byte\n", i);
printf("%s", buf);
if (buf[i-1] == MY_END_CHAR) {
break;
}
}
}
}
// reset_port(fd);
close(fd);
return 0;
}
static int baudflag_arr[] = {
B921600, B460800, B230400, B115200, B57600, B38400,
B19200, B9600, B4800, B2400, B1800, B1200,
B600, B300, B150, B110, B75, B50
};
static int speed_arr[] = {
921600, 460800, 230400, 115200, 57600, 38400,
19200, 9600, 4800, 2400, 1800, 1200,
600, 300, 150, 110, 75, 50
};
/******************************************************************************
* NAME:
* speed_to_flag
*
* DESCRIPTION:
* Translate baudrate into flag
*
* PARAMETERS:
* speed - The baudrate to convert
*
* RETURN:
* The flag
******************************************************************************/
int speed_to_flag(int speed)
{
int i;
for (i = 0; i < sizeof(speed_arr)/sizeof(int); i++) {
if (speed == speed_arr) {
return baudflag_arr;
}
}
fprintf(stderr, "Unsupported baudrate, use 9600 instead!\n");
return B9600;
}
static struct termio oterm_attr;
/******************************************************************************
* NAME:
* stup_port
*
* DESCRIPTION:
* Set serial port (include baudrate, line control)
*
* PARAMETERS:
* fd - The fd of serial port to setup
* baud - Baudrate: 9600, ...
* databits - Databits: 5, 6, 7, 8
* parity - Parity: 0(None), 1(Odd), 2(Even)
* stopbits - Stopbits: 1, 2
*
* RETURN:
* 0 for OK; Others for ERROR
******************************************************************************/
int setup_port(int fd, int baud, int databits, int parity, int stopbits)
{
struct termio term_attr;
/* Get current setting */
if (ioctl(fd, TCGETA, &term_attr) < 0) {
return -1;
}
/* Backup old setting */
memcpy(&oterm_attr, &term_attr, sizeof(struct termio));
term_attr.c_iflag &= ~(INLCR | IGNCR | ICRNL | ISTRIP);
term_attr.c_oflag &= ~(OPOST | ONLCR | OCRNL);
term_attr.c_lflag &= ~(ISIG | ECHO | ICANON | NOFLSH);
term_attr.c_cflag &= ~CBAUD;
term_attr.c_cflag |= CREAD | speed_to_flag(baud);
/* Set databits */
term_attr.c_cflag &= ~(CSIZE);
switch (databits) {
case 5:
term_attr.c_cflag |= CS5;
break;
case 6:
term_attr.c_cflag |= CS6;
break;
case 7:
term_attr.c_cflag |= CS7;
break;
case 8:
default:
term_attr.c_cflag |= CS8;
break;
}
/* Set parity */
switch (parity) {
case 1: /* Odd parity */
term_attr.c_cflag |= (PARENB | PARODD);
break;
case 2: /* Even parity */
term_attr.c_cflag |= PARENB;
term_attr.c_cflag &= ~(PARODD);
break;
case 0: /* None parity */
default:
term_attr.c_cflag &= ~(PARENB);
break;
}
/* Set stopbits */
switch (stopbits) {
case 2: /* 2 stopbits */
term_attr.c_cflag |= CSTOPB;
break;
case 1: /* 1 stopbits */
default:
term_attr.c_cflag &= ~CSTOPB;
break;
}
term_attr.c_cc[VMIN] = 1;
term_attr.c_cc[VTIME] = 0;
if (ioctl(fd, TCSETAW, &term_attr) < 0) {
return -1;
}
if (ioctl(fd, TCFLSH, 2) < 0) {
return -1;
}
return 0;
}
/******************************************************************************
* NAME:
* read_data
*
* DESCRIPTION:
* Read data from serial port
*
*
* PARAMETERS:
* fd - The fd of serial port to read
* buf - The buffer to keep readed data
* len - The max count to read
*
* RETURN:
* Count of readed data
******************************************************************************/
int read_data(int fd, void *buf, int len)
{
int count;
int ret;
ret = 0;
count = 0;
//while (len > 0) {
ret = read(fd, (char*)buf + count, len);
if (ret < 1) {
fprintf(stderr, "Read error %s\n", strerror(errno));
//break;
}
count += ret;
len = len - ret;
//}
*((char*)buf + count) = 0;
return count;
}
/******************************************************************************
* NAME:
* write_data
*
* DESCRIPTION:
* Write data to serial port
*
*
* PARAMETERS:
* fd - The fd of serial port to write
* buf - The buffer to keep data
* len - The count of data
*
* RETURN:
* Count of data wrote
******************************************************************************/
int write_data(int fd, void *buf, int len)
{
int count;
int ret;
ret = 0;
count = 0;
while (len > 0) {
ret = write(fd, (char*)buf + count, len);
if (ret < 1) {
fprintf(stderr, "Write error %s\n", strerror(errno));
break;
}
count += ret;
len = len - ret;
}
return count;
}
/******************************************************************************
* NAME:
* print_usage
*
* DESCRIPTION:
* print usage info
*
* PARAMETERS:
* program_name - The name of the program
*
* RETURN:
* None
******************************************************************************/
void print_usage(char *program_name)
{
fprintf(stderr,
"*************************************\n"
" A Simple Serial Port Test Utility\n"
"*************************************\n\n"
"Usage:\n %s
" databits: 5, 6, 7, 8\n"
" parity: 0(None), 1(Odd), 2(Even)\n"
" stopbits: 1, 2\n"
" read_or_write: 0(read), 1(write)\n"
"Example:\n %s /dev/ttyS0 9600 8 0 1 0\n\n",
program_name, program_name
);
}
源码：
UART.rar
