clientpos.c

一个串口通讯的c语言的例子

// 对串口进行操作的程序
#include <stdio.h>						/* Standard input/output definitions */
#include <string.h>						/* String function definitions */
#include <unistd.h>						/* UNIX standard function definitions */
#include <fcntl.h>						/* File control definitions */
#include <errno.h>						/* Error number definitions */
#include <termio.h>						/* POSIX terminal control definitions */
#include <sys/time.h>
#include <sys/select.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <time.h>
#include <math.h>
#include <stdlib.h>
#include <sys/signal.h>

#define ETX  0x03
#define STX  0x02
#define PROMPT	"你想终止程序吗?\n"

char *prompt = PROMPT;

long getCurrTime(){
	long currTime; 
	time( &currTime );
    //printf( "Time in seconds since UTC 1/1/70:\t%ld\n", currTime );
	return currTime;
}

//读二进制文件
int readfile(char *filename,unsigned char *buf){
	FILE *stream;
	int ch ,len = 0;

	if( (stream = fopen( filename,"rb")) == NULL ){
		printf( "文件打开失败！\n" );
		return -1;
	}

	while ((ch = fgetc(stream)) != EOF){
		buf[len++] = (unsigned char)ch;
		printf( "[%02x]",ch );
	}
	printf( "\n");

	fclose( stream );
	return len;
}

//write to serial port
void writePort(int fd,unsigned char *buffer,int len){
	int k;

	printf("Writing data:\n");
	for ( k = 0; k < len; k++) {
		printf("[%02x]",buffer[k]);
		while (write(fd,buffer + k,1) != 1 );
	}
}

//read data from serial port and check data 
int readPort(int fd,unsigned char *buffer,int *length){
	int	i = 0, n, len, flag, timeout = 0;
	unsigned char lrc;							//unsigned char	lrc;
	long currTime1,currTime2;

	printf("read begin .....\n");
	if ( read(fd, buffer, 1) > 0 ) {
		if (buffer[0] == STX){
			printf("[%02x]", buffer[0] );
//			printf("OK Head!\n");
		}else{
			printf("Error Head!\n");
			return 0;
		}
	}else{
		printf("No data!\n");
		return 0;
	}

	currTime1=getCurrTime();
	
	for ( i = 0, n = 1, flag = 0, len = 0, lrc = '\x00'; ; ) {
		if (read(fd, &buffer[n], 1) > 0 ) {
			printf("[%02x]", buffer[n] );

			fflush(stdout);

			if ( flag < 2 ) {
				len = len*100+(((buffer[n] & 0xf0) >> 4) * 10 +(buffer[n] & 0x0f));
				lrc ^= buffer[n];
                flag++;
				n++;
			}else if ( flag == 2 && i++ < len ){
				*length=len+5;
				lrc ^= buffer[n];
				n++;
			}else if ( flag == 2 && i >= len ){
				if ( buffer[n] == ETX ){
					lrc ^= buffer[n];
					flag++;
					n++;
				} else {
					printf("\nETX not received\n" );
					return( -1 );
				}
			}else if ( flag == 3 ){
				if ( lrc != buffer[n] ) {
					printf("2 resp LRC: %2x, cacl LRC: %02x\n", buffer[n], lrc );
					return( -2 );
				} else {
					return( len );
				}
			}
		}else {
			printf("\nNot data\n" );
			currTime2 = getCurrTime();
			printf("\ntime=%d-%d\n",currTime2,currTime1);
			if( (currTime2-currTime1)>timeout){
				printf("\nTime out=%d\n", currTime2-currTime1);
				printf("\nTime out\n" );
				return( 0 );
			}
		}
	}
}

int setAttr(int fdread){
	struct termio comtty;
	
	if(ioctl(fdread,TCGETA,&comtty)){
		printf("\n[ERROR]: Get tty error\n" );
		return (-1);
	}

	comtty.c_iflag = 1;
	comtty.c_oflag = 0;
	comtty.c_cflag =(B9600|CS8|CREAD|HUPCL|CLOCAL);
	comtty.c_lflag = 0;
	comtty.c_cc[VMIN]=0;
	comtty.c_cc[VTIME]=1;

	if(ioctl(fdread,TCSETA,&comtty)==-1){
		printf("\n[ERROR]: Set tty error\n" );
		return (-1);
	}
}

int setNowait(int fd){
	struct termio term_attr;
	
	if(fd<0) return -1;
	
	if(ioctl(fd,TCGETA,&term_attr)<0)
		return -1;
	
	term_attr.c_cc[VMIN]=0;
	
	term_attr.c_cc[VTIME]=1;
	
	if(ioctl(fd,TCSETAW,&term_attr)<0)
		return -1;
	
	return 0;
}

//	处理信号
void ctrl_c_op(int signo){
	char c;
	write(STDERR_FILENO,prompt,strlen(prompt));
	fflush(stdin);
	c = getchar();
	if (c == 'y'|| c == 'Y')
		exit(0);
}

//主程序
int main(int argc,char *argv[]){
	char *pCOM1,*pCOM2;
//send use param			发送
	unsigned char buffer[1024];
	int fdr,fdw,ret,i=0,j;
//rcv use param				接收
	int rcvLen[3] = {0,0,0},packlen,starting=1;
	unsigned char rcvPack[3][1024],tpdu[6];

// 设置退出信号
	struct sigaction act;
	 
	act.sa_handler = ctrl_c_op;
	sigemptyset(&act.sa_mask);		// 将信号集合设置为空
	act.sa_flags = 0;

	if(sigaction(SIGQUIT,&act,NULL) < 0){			// CTRL-\ 退出当前进程，并生成主存储文件
		fprintf(stderr,"Install Signal Action Error:%s\n\a",strerror(errno));
		exit(1);
	}

//	得到输入参数（串口设备名）
	if(argc>2){
		pCOM1=argv[1];
		pCOM2=argv[2];
	}else{
		printf("\n请指明串口设备名! eg:\nclientpos /dev/tty2a /dev/tty1a\n");//读2，写1
		exit(0);
	}

//open port for read and write	打开端口读写
	printf("打开读写端口...\n");
	if( (fdr=open(pCOM1, O_RDONLY))<0 || (fdw=open(pCOM2,O_WRONLY))<0){
		printf("\n\r[ERROR]: Open serial  port for read or write %s failure....\n" ,argv[1]);

		return (-1);
	}
	printf("端口已成功打开...\n");
	setAttr(fdr);
	setNowait(fdr);

	setAttr(fdw);
	setNowait(fdw);

	printf("打开文件读数据...\n");
	rcvLen[0] = readfile("0400.log",rcvPack[0]);
	rcvLen[1] = readfile("IN98SEND",rcvPack[1]);
	rcvLen[2] = readfile("IN99SEND",rcvPack[2]);
	while(1){
		if(i>=3)	i=0;
		printf("\n开始写串口:%s........\n",pCOM2);
		writePort(fdw,rcvPack[i],rcvLen[i]);					//向串口写数据
		printf("写完串口！\n");
		i++;
		for (j=0;j<100000000;j++)		;
//		printf("开始读串口:%s...\n",pCOM1);
//		ret=readPort(fdr,buffer,&packlen);							//从串口读数据

//		printf("\nlenth:%i\n",ret);
//		if(ret>0)
//			printf("\nlenth:%i\n",ret);

//		printf("\n读完串口！\n");
	}
}