serprt.c

#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 <termios.h> /* POSIX terminal control definitions */
#include <stdlib.h>
#include "common.h"


int getbaud(int fd) {
  struct termios termAttr;
  int inputSpeed = -1;
  speed_t baudRate;
  tcgetattr(fd, &termAttr);
  /* Get the input speed.                              */
  baudRate = cfgetispeed(&termAttr);
  switch (baudRate) {
  case B0:      inputSpeed = 0; break;
  case B50:     inputSpeed = 50; break;
  case B110:    inputSpeed = 110; break;
  case B134:    inputSpeed = 134; break;
  case B150:    inputSpeed = 150; break;
  case B200:    inputSpeed = 200; break;
  case B300:    inputSpeed = 300; break;
  case B600:    inputSpeed = 600; break;
  case B1200:   inputSpeed = 1200; break;
  case B1800:   inputSpeed = 1800; break;
  case B2400:   inputSpeed = 2400; break;
  case B4800:   inputSpeed = 4800; break;
  case B9600:   inputSpeed = 9600; break;
  case B19200:  inputSpeed = 19200; break;
  case B38400:  inputSpeed = 38400; break;
  case B115200:  inputSpeed = 115200; break;
  }
  return inputSpeed;
}

int readport(int fd, unsigned char *result) {
  
  int iIn = read(fd, result, 254); //13); //254);
  
  //show result array
  int counter = 0;

  if (verbosity) {
  printf("result[] = ");
  while(counter < iIn) {
    printf("%d,",result[counter]);
    counter++;
  }
  printf("\n");
  }
  
  //result[iIn-1] = 0x00;
  if (iIn < 0) {
    if (errno == EAGAIN) {
      printf("SERIAL EAGAIN ERROR\n");
      return 0;
    } else {
      printf("SERIAL read error %d %s\n", errno, strerror(errno));
      return 0;
    }
  }                    
  return 1;
}

int writeport(int fd, unsigned char *chars, int numBytes) {
  
  //show array contents
  //printf("write array contents:\n");
  int counter = 0;
 
  if (verbosity>1) {
 printf("write array = ");
  while(counter < numBytes) {
    printf("%d,", chars[counter]);
    counter++;
  }
  printf("\n");
  }
  int n = write(fd, chars, numBytes); //strlen(chars));
  if (n < 0) {
    fputs("write failed!\n", stderr);
    return 0;
  }
  //all good
  return 1;
}

int initport(int fd) {
  struct termios options;
  // Get the current options for the port...
  tcgetattr(fd, &options);
  // Set the baud rates to 115200...
  cfsetispeed(&options, B9600);
  cfsetospeed(&options, B9600);
  // Enable the receiver and set local mode...
  options.c_cflag |= (CLOCAL | CREAD);
  
  //disable hardware flow control
  //  options.c_cflag &= ~CRTSCTS;

  //disable software flow control
  //options.c_iflag &= ~(IXON | IXOFF | IXANY);

  //raw input
  //options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
  
  //raw output
  //options.c_oflag &= ~OPOST;
  
  //No parity - 8N1
  options.c_cflag &= ~PARENB;
  options.c_cflag &= ~CSTOPB;
  options.c_cflag &= ~CSIZE;
  options.c_cflag |= CS8;

  // Set the new options for the port...
  tcsetattr(fd, TCSANOW, &options);
  
   
  return 1;
}

int setupport(char *fdpath){
  int fd = open(fdpath, O_RDWR | O_NOCTTY | O_NDELAY);

  if (fd == -1) {
    perror("open_port: Unable to open dev - ");
    return 1;
  } else {
    fcntl(fd, F_SETFL, 0);
    //fcntl(fd, F_SETFL, FNDELAY);
  }
  if (verbosity) {
  printf("baud=%d\n", getbaud(fd));
  }
  return fd;
}