Source file: /~heha/hs/UNI-T/dmm.zip/src/Metex.cpp

#include "dmm.h"
#include <string.h>			// memcpy(), strchr()
#include <math.h>			// pow()

EXTERN_C void _cdecl _fltused(){};	// don't create .bss data segment here!

struct Metex:INDATA{
 void _stdcall Handler();
};

void Metex::Handler() {
 switch (msg) {
  case init:{
   rmax=32;
   counts=lParam?19999:99999;		// TODO: guessed
   baud=lParam?1200:2400;
  }break;

  case data:{
   if (rlen<14) {ok=true; return;}	// Expect more data
   for (int i=0; i<14; i++) rbuf[i]&=~0x80;	// strip MSB (stop bit), TODO: Remove this quirks!
   if (rbuf[13]!='\r') return;		// Ignore more characters, but newline must be at right position
   READOUT ro;
   ZeroMemory(&ro,sizeof(ro));
   memcpy(ro.digits,rbuf+2,7);
   ro.value=strtod(ro.digits,NULL);
   // TODO: No information for accuracy available, data sheet of ME-22T is needed
   for (BYTE*a=rbuf+9; a<rbuf+13; a++) if (*a!=' ') {	// found a unit
    static const char prefixes[]="pnum KMG";	// possible SI unit prefixes
    const char*p=strchr(prefixes,*a);
    if (p) {				// unit prefix detected
     ro.unitprefix=(char)(p-prefixes-4)*3;	// calculate exponent
     ro.value*=pow(10.0,ro.unitprefix);	// adjust value (beware C++ overloading of pow()!)
     a++;				// to base unit
    }
    static const char unitletters[]=" VOFHAC";	// first letter of base unit
    p=strchr(unitletters,*a);
    if (p) ro.unitcode=(char)(p-unitletters);	// known unit
    else memcpy(ro.unit,a,rbuf+13-a);	// unknown unit
    break;
   }
   DWORD features=0;
   switch (*(WORD*)rbuf) {
    case 'CA': features|=1<<F_AC; break;	// "AC" (TODO: Including DC or not?)
    case 'CD': features|=1<<F_DC; break;	// "DC"
    case 'FH': features|=1<<F_hFE; break;	// "HF" (for hFE)
    case 'ID': features|=1<<F_Diode; break;	// "DI" (diode and continuity test)
   }					// moreover FRequency, TEmperature, OHm, LOgic
   SetData(features,&ro,1);
   rlen=0;
   ok=true;
  }nobreak;

  case tout:
  case open:{
   SendBytes("\xC4",1);			// "D" with stop bit
  }break;
 }
}

EXTERN_C bool /*_declspec(dllexport)*/ WINAPI EnumAll(int n, ENUMINFO* ei) {
 if (n>=2) return false;
 strcpy(ei->ManufName,"Metex");
 strcpy(ei->ModelName,n?"M4650CR":"ME-22T");
 ei->IconIndex=0;
 ei->ExtraAlloc=0;
 ei->pHandler=(void(_stdcall INDATA::*)())&Metex::Handler;
 ei->lParam=n;
 return true;
}