#include <stdbool.h>
  #include <termios.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <strings.h>
  #include "serial.h"
  
  #define	WAIT_BEFORE_RETRY	50000
  
  bool init_serial(char* device, int speed, int *serial_fd, struct termios *saveterm)
  {
  	struct termios new;
  
  	int fd=open(device,O_RDWR|O_NOCTTY|O_NONBLOCK);
  	
  	if(fd<0)
  		return false;
  
  	tcgetattr(fd,saveterm); // save current port settings
  	bzero(&new,sizeof(new));
  	new.c_cflag=CLOCAL|CREAD|speed|CS8;
  	new.c_iflag=0;
  	new.c_oflag=0;
  	new.c_lflag=0;  // set input mode (non-canonical, no echo,...)
  	new.c_cc[VTIME]=0; // inter-character timer unused
  	new.c_cc[VMIN]=1; // blocking read until 1 char received
  	tcflush(fd, TCIFLUSH);
  	tcsetattr(fd,TCSANOW,&new);
  
  	*serial_fd = fd;
  	sleep(2);
  	return true;
  }
  
  void close_serial(int *serial_fd, struct termios *saveterm)
  {
  	tcsetattr(*serial_fd,TCSANOW,saveterm);
  	close(*serial_fd);
  }
  
  unsigned char getData(int *serial_fd)
  {
  	unsigned char buf;
  	while(read(*serial_fd, &buf, 1) != 1)
  		usleep(WAIT_BEFORE_RETRY);
  		return buf;
  }
  
  void sendData(int *serial_fd, unsigned char data)
  {
  	while(write(*serial_fd, &data, 1) != 1)
  		usleep(WAIT_BEFORE_RETRY);
  }