/*
 * Data Logging Format Converter for QM1538 Multimeter,
 * Author: telford@bespoke.homelinux.net
 * Copyright: Telford Tendys 2007
 * Version: 2007-01-18
 *
 * The author releases this work into the public domain.
 * This comes with NO WARRANTY, it is the responsibility of
 * the user to review this code and asses fitness for purpose.
 */

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <termios.h>
#include <unistd.h>

struct seg7_S
{
  char S1;
  char S2;
  char S3;
  char S4;
  char S5;
  char S6;
  char S7;
};

struct reading_S
{
  /*
   * Reading digits
   */
  char negative;
  char dig[4];
  char dp1;
  char dp2;
  char dp3;

  /*
   * Reading scale-factors
   */
  char mega;
  char kilo;
  char milli;
  char micro;
  char nano;
  char percent;

  /*
   * Reading units
   */
  char ac;
  char amp;
  char dc;
  char farad;
  char hertz;
  char volt;
  char ohm;

  /*
   * Other flags
   */
  char autorange;
  char battery;
  char beeper;
  char delta;
  char diode; /* Is this a unit?!? */
  char hold;
  char rs232;
};

int seg2digit( struct seg7_S *S )
{
  int x = 0;

  if( S->S1 ) x += 0x01;
  if( S->S2 ) x += 0x02;
  if( S->S3 ) x += 0x04;
  if( S->S4 ) x += 0x08;
  if( S->S5 ) x += 0x10;
  if( S->S6 ) x += 0x20;
  if( S->S7 ) x += 0x40;
  
  switch( x )
    {
    case 0x3F: return( '0' ); 
    case 0x06: return( '1' );
    case 0x5B: return( '2' );
    case 0x4F: return( '3' );
    case 0x66: return( '4' );
    case 0x6D: return( '5' );
    case 0x7D: return( '6' );
    case 0x07: return( '7' );
    case 0x7F: return( '8' );
    case 0x6F: return( '9' );
      
    default:
      fprintf( stderr, "illegal digit %02X\n", x );
      fprintf( stderr, "    %c%c%c\n", S->S1 ? '#' : ' ', S->S1 ? '#' : ' ', S->S1 ? '#' : ' ' );
      fprintf( stderr, "   %c   %c\n", S->S6 ? '#' : ' ', S->S2 ? '#' : ' ' );
      fprintf( stderr, "   %c   %c\n", S->S6 ? '#' : ' ', S->S2 ? '#' : ' ' );
      fprintf( stderr, "   %c   %c\n", S->S6 ? '#' : ' ', S->S2 ? '#' : ' ' );
      fprintf( stderr, "    %c%c%c\n", S->S7 ? '#' : ' ', S->S7 ? '#' : ' ', S->S7 ? '#' : ' ' );
      fprintf( stderr, "   %c   %c\n", S->S5 ? '#' : ' ', S->S3 ? '#' : ' ' );
      fprintf( stderr, "   %c   %c\n", S->S5 ? '#' : ' ', S->S3 ? '#' : ' ' );
      fprintf( stderr, "   %c   %c\n", S->S5 ? '#' : ' ', S->S3 ? '#' : ' ' );
      fprintf( stderr, "    %c%c%c\n", S->S4 ? '#' : ' ', S->S4 ? '#' : ' ', S->S4 ? '#' : ' ' );
      return( 'X' );
    }
}

char *serial_filename = "/dev/ttyS0";
int ser_dev;
int real_numbers = 0;

int main( int argc, char *argv[] )
{
  struct termios TIO;
  struct reading_S reading;
  struct seg7_S seg7;

  for(;;)
    {
      int i = getopt( argc, argv, "n" );

      switch( i )
	{
	case 'n': real_numbers = 1; break;
	case -1: goto dunops;
	}
    }
 dunops:

  ser_dev = open( serial_filename, O_RDONLY );
  if( ser_dev < 0 ) { perror( "open serial device" ); exit( -1 ); }
  if( 0 > tcgetattr( ser_dev, &TIO )) { perror( "get serial attributes" ); exit( -1 ); }
  cfmakeraw( &TIO );
  cfsetispeed( &TIO, B2400 );
  cfsetospeed( &TIO, B2400 );
  if( 0 > tcsetattr( ser_dev, TCSAFLUSH, &TIO )) { perror( "set serial attributes" ); exit( -1 ); }
  
  for(;;)
    {
      char buf[ 4 ];
      int i;

      if( 1 != read( ser_dev, buf, 1 ))
	{
	  perror( "read" );
	  exit( -1 );
	}
      i = buf[ 0 ] & 0x0F;
      switch(( buf[ 0 ] & 0x00F0 ) >> 4 )
	{
	case 1:
	  bzero( &reading, sizeof( reading ));
	  reading.rs232        = ( i & 0x01 );
	  reading.autorange    = ( i & 0x02 );
	  reading.dc           = ( i & 0x04 );
	  reading.ac           = ( i & 0x08 );
	  break;

	case 2:
	  bzero( &seg7, sizeof( seg7 ));
	  seg7.S1              = ( i & 0x01 );
	  seg7.S6              = ( i & 0x02 );
	  seg7.S5              = ( i & 0x04 );
	  reading.negative     = ( i & 0x08 );
	  break;

	case 3:
	  seg7.S2              = ( i & 0x01 );
	  seg7.S7              = ( i & 0x02 );
	  seg7.S3              = ( i & 0x04 );
	  seg7.S4              = ( i & 0x08 );
	  reading.dig[ 0 ]     = seg2digit( &seg7 );
	  break;

	case 4:
	  bzero( &seg7, sizeof( seg7 ));
	  seg7.S1              = ( i & 0x01 );
	  seg7.S6              = ( i & 0x02 );
	  seg7.S5              = ( i & 0x04 );
	  reading.dp1          = ( i & 0x08 );
	  break;

	case 5:
	  seg7.S2              = ( i & 0x01 );
	  seg7.S7              = ( i & 0x02 );
	  seg7.S3              = ( i & 0x04 );
	  seg7.S4              = ( i & 0x08 );
	  reading.dig[ 1 ]     = seg2digit( &seg7 );
	  break;

	case 6:
	  bzero( &seg7, sizeof( seg7 ));
	  seg7.S1              = ( i & 0x01 );
	  seg7.S6              = ( i & 0x02 );
	  seg7.S5              = ( i & 0x04 );
	  reading.dp2          = ( i & 0x08 );
	  break;

	case 7:
	  seg7.S2              = ( i & 0x01 );
	  seg7.S7              = ( i & 0x02 );
	  seg7.S3              = ( i & 0x04 );
	  seg7.S4              = ( i & 0x08 );
	  reading.dig[ 2 ]     = seg2digit( &seg7 );
	  break;

	case 8:
	  bzero( &seg7, sizeof( seg7 ));
	  seg7.S1              = ( i & 0x01 );
	  seg7.S6              = ( i & 0x02 );
	  seg7.S5              = ( i & 0x04 );
	  reading.dp3          = ( i & 0x08 );
	  break;

	case 9:
	  seg7.S2              = ( i & 0x01 );
	  seg7.S7              = ( i & 0x02 );
	  seg7.S3              = ( i & 0x04 );
	  seg7.S4              = ( i & 0x08 );
	  reading.dig[ 3 ]     = seg2digit( &seg7 );
	  break;

	case 10:
	  reading.diode        = ( i & 0x01 );
	  reading.kilo         = ( i & 0x02 );
	  reading.nano         = ( i & 0x04 );
	  reading.micro        = ( i & 0x08 );
	  break;

	case 11:
	  reading.beeper       = ( i & 0x01 );
	  reading.mega         = ( i & 0x02 );
	  reading.percent      = ( i & 0x04 );
	  reading.milli        = ( i & 0x08 );
	  break;

	case 12:
	  reading.hold         = ( i & 0x01 );
	  reading.delta        = ( i & 0x02 );
	  reading.ohm          = ( i & 0x04 );
	  reading.farad        = ( i & 0x08 );
	  break;

	case 13:
	  reading.battery      = ( i & 0x01 );
	  reading.hertz        = ( i & 0x02 );
	  reading.volt         = ( i & 0x04 );
	  reading.amp          = ( i & 0x08 );
	  break;

	case 14:
	  if( real_numbers )
	    {
	      double d;
	      d = reading.dig[ 0 ] - '0';
	      d *= 10;
	      d += reading.dig[ 1 ] - '0';
	      d *= 10;
	      d += reading.dig[ 2 ] - '0';
	      d *= 10;
	      d += reading.dig[ 3 ] - '0';
	      if( reading.dp1 )
		d *= 0.001;
	      else if( reading.dp2 )
		d *= 0.01;
	      else if( reading.dp3 )
		d *= 0.1;
	      if( reading.mega )
		d *= 1000000;
	      else if( reading.kilo )
		d *= 1000;
	      else if( reading.milli )
		d *= 0.001;
	      else if( reading.micro )
		d *= 0.000001;
	      else if( reading.nano )
		d *= 0.000000001;

	      if( reading.negative ) d = -d;

	      printf( "%g", d );
	    }
	  else
	    {
	      /* I give up wtf are these bits for? */
	      if( reading.negative ) printf( "-" );
	      printf( "%c", reading.dig[ 0 ]);
	      if( reading.dp1 ) printf( "." );
	      printf( "%c", reading.dig[ 1 ]);
	      if( reading.dp2 ) printf( "." );
	      printf( "%c", reading.dig[ 2 ]);
	      if( reading.dp3 ) printf( "." );
	      printf( "%c", reading.dig[ 3 ]);
	      if( reading.mega ) printf( "M" );
	      if( reading.kilo ) printf( "k" );
	      if( reading.milli ) printf( "m" );
	      if( reading.micro ) printf( "u" );
	      if( reading.nano ) printf( "n" );
	    }

	  if( reading.percent ) printf( "%" );
	  if( reading.ac ) printf( " AC" );
	  if( reading.dc ) printf( " DC" );
	      
	  if( reading.amp ) printf( " Amp" );
	  if( reading.farad ) printf( " Farad" );
	  if( reading.hertz ) printf( " Hertz" );
	  if( reading.volt ) printf( " Volt" );
	      
	  /*
	   * Dunno how many of the other flags are useful
	   * battery seems the most important to me
	   */
	  printf( " (" );
	  if( reading.autorange ) printf( " auto" );
	  if( reading.battery ) printf( " battery" );
	  if( reading.delta ) printf( " delta" );
	  if( reading.hold ) printf( " hold" );
	  printf( ")\n" );
	  break;
	}
      /*
       * printf( "%02X\n", 0x00FF & buf[ 0 ]);
       */
    }
}