nsser.c

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#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include "nsutil.h"
#include "nsser.h"



ser_t openSerialPort(const char *devname, unsigned int BaudRate)
{
#ifdef __MINGW32__
        ser_t retval;
        retval = CreateFile(devname,
        GENERIC_READ | GENERIC_WRITE,
        0, NULL, OPEN_EXISTING,
            FILE_ATTRIBUTE_NORMAL, NULL);
        if (retval == INVALID_HANDLE_VALUE) {
         rprintf("Couldn't open serial port: %s", devname);
                rexit(1);
        }
        if (!SetCommMask(retval, EV_RXCHAR))
        rprintf("Couldn't do a SetCommMask(): %s", devname);

        // Set read buffer == 10K, write buffer == 4K
        SetupComm(retval, 10240, 4096);

        do {
        DCB dcb;

        dcb.DCBlength= sizeof(DCB);
        GetCommState(retval, &dcb);
        switch(BaudRate) {
         case 19200: dcb.BaudRate=CBR_19200;break;
         case 57600: dcb.BaudRate=CBR_57600;break;
         case 115200: dcb.BaudRate=CBR_115200;break;
         default: dcb.BaudRate=CBR_57600;
        } 
                dcb.ByteSize= 8;
                dcb.Parity= NOPARITY;
                dcb.StopBits= ONESTOPBIT;
                dcb.fOutxCtsFlow= FALSE;
                dcb.fOutxDsrFlow= FALSE;
                dcb.fInX= FALSE;
                dcb.fOutX= FALSE;
                dcb.fDtrControl= DTR_CONTROL_DISABLE;
                dcb.fRtsControl= RTS_CONTROL_DISABLE;
                dcb.fBinary= TRUE;
                dcb.fParity= FALSE;

        if (!SetCommState(retval, &dcb)) {
                        rprintf("%s", "Unable to set up serial port parameters");
                        rexit(1);
                }
        } while (0);
        return retval;
#else
        ser_t fd; /* File descriptor for the port */


        fd = open(devname, O_RDWR | O_NOCTTY | O_NDELAY);
        if (fd == -1)
                {
                fprintf(stderr, "Cannot open port %s\n", devname);
                exit(1);
                }
        else
                fcntl(fd, F_SETFL, FNDELAY);
        set_port_options(fd,BaudRate);
        return (fd);
#endif
}
/* Returns number of bytes read, or -1 for error */
#ifdef __MINGW32__
int readSerial(ser_t s, char *buf, int size)
{
   BOOL rv;
   COMSTAT comStat;
   DWORD errorFlags;
   DWORD len;
   // Only try to read number of bytes in queue
   ClearCommError(s, &errorFlags, &comStat);
   len = comStat.cbInQue;
   if (len > size) len = size;
   if (len > 0) {
      rv = ReadFile(s, (LPSTR)buf, len, &len, NULL);
                        if (!rv) {
                                 len= 0;
                                 ClearCommError(s, &errorFlags, &comStat);
                        }
                if (errorFlags > 0) {
                        rprintf("Serial read error");
                        ClearCommError(s, &errorFlags, &comStat);
                        return -1;
                }
        }
        return len;
}
#else

int readSerial(ser_t s, char *buf, int size)
{
        int retval;
        retval = read(s, buf, size);
        if (retval < 0)
                retval = 0;
        return retval;
}


int writeSerial(ser_t s, char *buf, int size)
{
        int retval;
        retval = write(s, buf, size);
        if (retval < 0)
                retval = 0;
        return retval;
}

int set_port_options(int fd, unsigned int BaudRate)
{
        int retval;
        struct termios options;
/*
 *      * Get the current options for the port...
 *      */

    retval = tcgetattr(fd, &options);
                assert(retval == 0 && "tcgetattr problem");

/*
 *      * Set the baud rates to 19200...
 *      */
        switch(BaudRate) {
         case 19200:  cfsetispeed(&options, B19200);cfsetospeed(&options, B19200);break;
         case 57600:  cfsetispeed(&options, B57600);cfsetospeed(&options, B57600);break;
         case 115200:  cfsetispeed(&options, B115200);cfsetospeed(&options, B115200);break;
         default: cfsetispeed(&options, B57600);cfsetospeed(&options, B57600);
        } 
   


/*
 *      * Enable the receiver and set local mode...
 *      */

    options.c_cflag |= (CLOCAL | CREAD);

/* 8-N-1 */
options.c_cflag &= ~PARENB;
options.c_cflag &= ~CSTOPB;
options.c_cflag &= ~CSIZE;
options.c_cflag |= CS8;

/* Disable flow-control */
  options.c_cflag &= ~CRTSCTS;

/* Raw processing mode */
        options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);





/*
 *      * Set the new options for the port...
 *      */

        retval = tcsetattr(fd, TCSANOW, &options);
        return retval;
}
#endif

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