#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>			/* File control definitions */
#include <errno.h>			/* Error number definitions */
#include <termios.h>		/* POSIX terminal control definitions */
#include <sys/time.h>

#include <io.h> 

int fd, fser1, fser2;
  
int baud, parity;

int open_port(void) {
	int fd;		// File Descriptor for serial port
	char s[60]="/dev/com4";
	baud=19200;
	parity=0;
	
	printf("Checking communication port : %s\n",s);
	fd = open(s, O_RDWR | O_NOCTTY | O_NDELAY); 
	if(fd == -1) {
		perror("-- Unable to open /dev/com --");
		exit(1);
	}	else {
		fcntl(fd, F_SETFL, 0);
		printf("...Done\n");
	}
	
	return(fd);
}

void init_port(int fd) {
	struct termios configs;
	
	tcgetattr(fd, &configs);
	
	switch(baud) {
		case 9600: baud=B9600;break;
		case 19200: baud=B19200;break;
		case 38400: baud=B38400;break;
		default: baud=B19200;
	}
	cfsetispeed(&configs, baud);
	cfsetospeed(&configs, baud);
	
	// Setting Control Mode
	switch (parity) {
		case 1:  // even parity
			 configs.c_cflag |= PARENB;		// Parity enable
			 configs.c_cflag &= ~PARODD;		// Even Parity
			 break;
		case 2:  // odd parity
			 configs.c_cflag |= PARENB;		// Parity enable
			 configs.c_cflag |= PARODD;		// Even Parity
			 break;
		default : // no parity
			 //configs.c_cflag |= PARENB;		// Parity enable
			 //configs.c_cflag &= ~PARODD;		// Even Parity
			 configs.c_cflag &= ~PARENB;  // Parity disable
	}
	configs.c_cflag &= ~CSTOPB;		// 1 stop bit
	//configs.c_cflag |= CSTOPB;		// 2 stop bit
	configs.c_cflag &= ~CSIZE;
	configs.c_cflag |= CS8;			// 8-bit data
	configs.c_cflag &= ~CRTSCTS;	// Disable hardware flow control
	
	// Setting Local Mode
	configs.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);	//RAW input
	
	// Setting Input mode
	configs.c_iflag |= INPCK;			// Enabling Parity Check
	configs.c_iflag &= ~ISTRIP;			// Disable strip off 8th bit when received
	configs.c_iflag &= ~(IXON | IXOFF | IXANY);	// Disable software flow control
	
	// Setting Output Mode
	configs.c_oflag &= ~OPOST;		// RAW output
	
	// Setting Control chars
	configs.c_cc[VTIME] = 0;		// Timeout in 0.1s, 0 (no timeout)
	configs.c_cc[VMIN] = 0;
	
	tcflush(fd, TCIFLUSH); // clean line
	
	if (tcsetattr(fd, TCSANOW, &configs)!=0) {
		fprintf(stderr, "ERROR ! Unable to write configuration to hardware\n");
	}
}


int main(int argc, char **argv) {
	FILE *fdata;
	int comm, count,n;
	unsigned char i;
	fd_set read_fd;
	struct timeval tv;
  tv.tv_sec=0;
	tv.tv_usec=100;

 	unsigned char test[10];
	
	//Open serial port
	fd = open_port();
	
	//Initialize serial
	init_port(fd);
	
	int fd0, retval;
	struct timeval tv0, tv1;
	
  gettimeofday(&tv0, NULL);
	printf("start reading..\n");
	while(1) {
				gettimeofday(&tv1, NULL);
				fcntl(fd, F_SETFL, FNDELAY);  // set reading as non blocking 
				n=read(fd, &test, 10); // return -1 in version 1.7.10 and up
				if (n>0) {
					printf("%d, ",(tv1.tv_sec-tv0.tv_sec)*1000+(tv1.tv_usec/1000-tv0.tv_usec/1000));
				  printf("read (%d bytes) : ", n);
				  for (i=0;i<n;i++)
				    printf("%x ", test[i]);
				  printf("\n");
				} else
				  printf("%d \n",n);
	}
  close(fd);
	return 0;
}