linux和单片机的串口通信

最近做无线传输方面的东西，需要cc2430开发板和tq2440进行数据串口通信。os为linux。

linux驱动在移植后时已经写好了，所以直接写应用层的程序即可，跟pc的写法类似。

修改自tq的serial_test demo程序，由pc端得串口ttyS0和tq2440的uart1口进行数据通信，互发字符串。

Uart.h文件：

#ifndef UART2_H

#define UART2_H

#define FALSE0

#define TRUE1

#define WORDLEN32

struct serial_config

{

unsigned char serial_dev[WORDLEN];

unsigned int serial_speed;

unsigned char databits;

unsigned char stopbits;

unsigned char parity;

};

#endif

Uart.c文件:

//--------------------------------------------------------------

// xiaoyang linux uart driver test

// 2011.4.24

//

// Work as console,collect the data from uart2.

//uart0:Debug

//uart1:free

//uart2:data path

//--------------------------------------------------------------

#include

#include

#include //文件控制定义

#include //posix中断控制定义

#include //错误定义

#include

#include

#include

#include

#include

#include

#include "pthread.h"

#include "uart2.h"

struct serial_config Uart2_Cfg;

static int serial_fd,beep_fd;

const int speed_arr[] = {

B230400, B115200, B57600, B38400, B19200, B9600, B4800, B2400, B1200, B300,

B38400, B19200, B9600, B4800, B2400, B1200, B300

};

const int name_arr[] = {

230400, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 300,

38400, 19200, 9600, 4800, 2400, 1200, 300

};

//-----------------------------------------------

//print content of uart2.cfg

//-----------------------------------------------

void print_serialread()

{

printf("serialread.dev is %sn",Uart2_Cfg.serial_dev);

printf("Uart2_Cfg.speed is %dn",Uart2_Cfg.serial_speed);

printf("Uart2_Cfg.databits is %dn",Uart2_Cfg.databits);

printf("Uart2_Cfg.stopbits is %dn",Uart2_Cfg.stopbits);

printf("Uart2_Cfg.parity is %cn",Uart2_Cfg.parity);

}

//-----------------------------------------------

//read uart2.cfg

//-----------------------------------------------

void read_uart2_cfg()

{

FILE *serial_fp;

char tmp[10];

//读取配置文件

serial_fp = fopen("/etc/uart2.cfg","r");

if(NULL == serial_fp)

{

printf("can't open /etc/tq2440_serial.cfgrn");

}

else

{

fscanf(serial_fp, "DEV=%sn", Uart2_Cfg.serial_dev);

fscanf(serial_fp, "SPEED=%sn", tmp);

Uart2_Cfg.serial_speed = atoi(tmp);

fscanf(serial_fp, "DATABITS=%sn", tmp);

Uart2_Cfg.databits = atoi(tmp);

fscanf(serial_fp, "STOPBITS=%sn", tmp);

Uart2_Cfg.stopbits = atoi(tmp);

fscanf(serial_fp, "PARITY=%sn", tmp);

Uart2_Cfg.parity = tmp[0];

}

fclose(serial_fp);

printf("uart cfg read overrn");

}

//-----------------------------------------------

//set boardrate

//-----------------------------------------------

void set_speed(int fd)

{

int i;

int status;

struct termios Opt;

if(tcgetattr(fd,&Opt) != 0){

perror("error: set_speed tcgetattr failed!");

return ;

}

for( i = 0; i < sizeof(speed_arr)/sizeof(int); i++)

{

if(Uart2_Cfg.serial_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("error: set_speed tcsetattr failed!");

return;

}

tcflush(fd, TCIOFLUSH);

}

}

}

//-----------------------------------------------

//set other parity

//-----------------------------------------------

int set_parity(int fd)

{

struct termios options;

if(tcgetattr(fd, &options) != 0)

{

perror("error: set_parity tcgetattr failed!");

return(FALSE);

}

options.c_cflag |= (CLOCAL|CREAD);

options.c_cflag &=~CSIZE;

//set data bits lenghth

switch(Uart2_Cfg.databits)

{

case 7:

options.c_cflag |= CS7;

break;

case 8:

options.c_cflag |= CS8;

break;

default:

options.c_cflag |= CS8;

fprintf(stderr, "Unsupported data sizen");

return(FALSE);

}

switch(Uart2_Cfg.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;

break;

case 'e':

case 'E':

options.c_cflag |= PARENB;

options.c_cflag &= ~PARODD;

options.c_iflag |= INPCK;

break;

default:

options.c_cflag &= ~PARENB;

options.c_iflag &= ~INPCK;

fprintf(stderr, "Unsupported parityn");

return(FALSE);

}

//set stop bits

switch(Uart2_Cfg.stopbits)

{

case 1:

options.c_cflag &= ~CSTOPB;

break;

case 2:

options.c_cflag |= CSTOPB;perror("error: set_parity tcgetattr failed!");

break;

default:

options.c_cflag &= ~CSTOPB;

fprintf(stderr, "Unsupported stop bitsn");

return(FALSE);

}

if(Uart2_Cfg.parity != 'n')

options.c_iflag |= INPCK;

options.c_cc[VTIME] = 0;//150,15 seconds

options.c_cc[VMIN] = 0;

#if 1

options.c_iflag |= IGNPAR|ICRNL;

options.c_oflag |= OPOST;

options.c_iflag &= ~(IXON|IXOFF|IXANY);

#endif

tcflush(fd, TCIFLUSH);

if(tcsetattr(fd, TCSANOW, &options) != 0)

{

perror("error: set_parity tcsetattr failed!");

return(FALSE);

}

return(TRUE);

}

//-----------------------------------------------

//open device

//-----------------------------------------------

int open_dev(char *dev)

{

int fd = open(dev, O_RDWR, 0);

if(-1 == fd)

{

perror("Can't Open Serial Port");

return -1;

}

else

return fd;

}

//--------------------------------------------------

//uart initialization

//--------------------------------------------------

void uart2_init(void)

{

char *dev;

int i;

read_uart2_cfg();

print_serialread();

dev = Uart2_Cfg.serial_dev;

serial_fd = open_dev(dev);

if(serial_fd > 0)

set_speed(serial_fd);

else

{

printf("Can't Open Serial Port!n");

exit(0);

}

//恢复串口未阻塞状态

if (fcntl(serial_fd, F_SETFL, O_NONBLOCK) < 0)

{

printf("fcntl failed!n");

exit(0);

}

//检查是否是终端设备

if(isatty(STDIN_FILENO)==0)

{

printf("standard input is not a terminal devicen");

}

else

printf("isatty success!n");

//设置串口参数

if(set_parity(serial_fd) == FALSE)

{

printf("Set parity Errorn");

exit(1);

}

}

//--------------------------------------------------

//uart test demo

//--------------------------------------------------

void uart2_test()

{

int i;

char rx_buffer[512];

char tx_buffer[] = "this is tquart2_init2440 consolen";

int nread,nwrite;

nwrite = write(serial_fd,tx_buffer,sizeof(tx_buffer));

printf("nwrite len=%drn",nwrite);

while(1)

{

if((nread = read(serial_fd,rx_buffer,512))>0)

{

rx_buffer[nread] = '';

printf("nrecv len:%drn",nread);

printf("content:%s",rx_buffer);

printf("rn");

}

}

close(serial_fd);

}

int main(int argc, char **argv)

{

uart2_init();

uart2_test();

return 0;

}

makefile：

#

# uart2驱动测试

# xiaoyang yi@2011.4.24

#

CC = arm-linux-gcc

LD = arm-linux-ld

EXEC = uart2

OBJS = uart2.o

all: $(EXEC)

$(EXEC): $(OBJS)

$(CC) $(LDFLAGS) -o $@ $(OBJS) -lpthread

rm -f *.o

clean:

-rm -f $(EXEC) *.elf *.gdb *.o

tq2440终端：

pc串口0终端：