vc820.cpp

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//======================================================================
// File:        vc820.cpp
// Author:      Matthias Toussaint
// Created:     Sun Nov 26 11:38:20 CET 2006
// Project:     QtDMM
// Description: Encapsulates a DMM class (protokoll)
//----------------------------------------------------------------------
// This file  may  be used under  the terms of  the GNU  General Public
// License  version 2.0 as published   by the Free Software  Foundation
// and appearing  in the file LICENSE.GPL included  in the packaging of
// this file.
// 
// This file is provided AS IS with  NO WARRANTY OF ANY KIND, INCLUDING 
// THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
// PURPOSE.
//----------------------------------------------------------------------
// Copyright 2006 Matthias Toussaint
//======================================================================

#include <vc820.h>

#include <iostream>

VC820::VC820() :
  DMMClass()
{
}

VC820::~VC820()
{
  m_port.close();
}

Port::Error VC820::open_impl( const std::string & config )
{
  return m_port.open( config );
}

Port::Error VC820::close()
{
  return m_port.close();
}

void VC820::run()
{
  unsigned char buffer[64];
  
  while (m_run)
  {
    // there seems to be no overflow bit!
    
    int cnt = readData( buffer );
  
    if (-1 != cnt)
    {
      unsigned char *byte = buffer+cnt-14;
      
      m_mutex.lock();
      
      // assemble digits
      //
      std::string digits;
      
      digits  = digitFromSegments( byte[1], byte[2] );
      digits += digitFromSegments( byte[3], byte[4] );
      digits += digitFromSegments( byte[5], byte[6] );
      digits += digitFromSegments( byte[7], byte[8] );
      
      double d_val;
      Util::fromString( &d_val, digits );
      
      // low battery
      //
      if (byte[12] & 0x01) m_lowBat = true;
      else                 m_lowBat = false;
      
      // decimal point
      //
      if      (byte[3] & 0x08) d_val /= 1000.0;
      else if (byte[5] & 0x08) d_val /= 100.0;
      else if (byte[7] & 0x08) d_val /= 10.0;
      
      // Negative
      //
      if      (byte[1] & 0x08) d_val *= -1.0;
      
      // unit
      //
      if      (byte[9] & 0x02)  m_unit[0] = "k";
      else if (byte[9] & 0x04)  m_unit[0] = "n";
      else if (byte[9] & 0x08)  m_unit[0] = "u";
      else if (byte[10] & 0x02) m_unit[0] = "M";
      else if (byte[10] & 0x08) m_unit[0] = "m";
      else if (byte[10] & 0x04) m_unit[0] = "%";
      else                      m_unit[0] = "";
      
      if      (byte[11] & 0x04) m_unit[0] += "Ohm";
      else if (byte[11] & 0x08) m_unit[0] += "F";
      else if (byte[12] & 0x02) m_unit[0] += "Hz";
      else if (byte[12] & 0x04) m_unit[0] += "V";
      else if (byte[12] & 0x08) m_unit[0] += "A";
      else if (byte[13] & 0x01) m_unit[0] += "C";
      
      std::cout<<(int)byte[13]<<std::endl;
      
      // mode
      //
      if (byte[12] & 0x0c) 
      {
        if   (byte[0] & 0x08) m_mode[0] = "AC";
        else                  m_mode[0] = "DC";
      }
      else if (byte[9] & 0x01)  m_mode[0] = "DI";
      else if (byte[11] & 0x04) m_mode[0] = "OH";
      else if (byte[11] & 0x08) m_mode[0] = "CA";
      else if (byte[12] & 0x02) m_mode[0] = "FR";
      else if (byte[13] & 0x01) m_mode[0] = "TE";
      else                      m_mode[0] = "";
      
      addValue( d_val, 0 );
      
      m_hasValue = true;
      m_mutex.unlock();
    }
    else
    {
      m_hasValue = false;
    }
  }
}

std::string VC820::digitFromSegments( unsigned char a, 
                                      unsigned char b ) const
{
  std::string digit;
  
  unsigned test = (b & 0x0f) | ((a & 0x07) << 4);
  
  switch (test)
  {
    case 0x7d:
      digit = "0";
      break;
    case 0x05:
      digit = "1";
      break;
    case 0x5b:
      digit = "2";
      break;
    case 0x1f:
      digit = "3";
      break;
    case 0x27:
      digit = "4";
      break;
    case 0x3e:
      digit = "5";
      break;
    case 0x7e:
      digit = "6";
      break;
    case 0x15:
      digit = "7";
      break;
    case 0x7f:
      digit = "8";
      break;
    case 0x3f:
      digit = "9";
      break;
  }
  
  return digit;
}

int VC820::readData( unsigned char *buffer ) const
{
  int cnt=0;
  int byte;
  
  do
  {
    if (m_port.readByte( &byte ) != Port::Ok)
    {
      return -1;
    }
    buffer[cnt++] = byte;
    
    if ((byte & 0xf0) == 0xe0 && cnt >= 14) return cnt;
  }
  while (cnt < 14 && (byte & 0xf0) != 0xe0);
  
  return -1;
}

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