{*-------------------------------------------------------------------
 *              C LANGUAGE SAMPLE 0
 *
 * Sample program for the Analog and Digital I/O card
 * demonstrating register level data aquistion.
 *
 * Last Modification : 16 May 2002.
 *------------------------------------------------------------------*}

uses Crt;

var
   base : Word;

function AskForBaseAddress(OldOne : String) : Word;
const
   Msg : string[8] = '0';
var
   NewOne, Success, Dummy, Error : Word;
   AddrInputPosX, AddrInputPosY : Word;
begin
   if (OldOne = 'OLD') then OldOne := Msg;
   WriteLn('Please enter the Base Address (100-FFFF) for your card (in hex)');
   WriteLn('or press ENTER for ', OldOne, '.  ');
   Write('>');
   AddrInputPosX := WhereX; AddrInputPosY := WhereY;
   Success := 0;
   repeat
      GotoXY(AddrInputPosX, AddrInputPosY);
      ClrEol;
      Readln(Msg);
      Val('$' + Msg, NewOne, Error);
      if NewOne >= $100 then begin
         Success := 1;
         Dummy := NewOne;
      end else if (Msg = '') then begin
         GotoXY(AddrInputPosX, AddrInputPosY);
         WriteLn(OldOne);
         Msg := OldOne;
         Success := 1;
         Val('$' + Msg, Dummy, Error);
      end;
   until (Success = 1);
   AskForBaseAddress := Dummy;
end;

procedure intro;
begin
   clrscr;
   writeln('Sample 0');
   writeln;
   writeln('This sample reads the sixteen analog inputs and ');
   writeln('displays them for you.');
   writeln;
   writeln;
   writeln('Board Configuration Requirements:');
   writeln;
   writeln('CHANNEL SELECTION:  16 Channel Single-Ended');
   writeln; writeln;
   writeln('Please press any key to set base address.');
   readkey;

   clrscr;
   base := AskForBaseAddress('300');
   clrscr;

end; { end of Intro }


var
   channel, counts, i : integer;
   volts : real;

begin
   intro;

   { Init AD816 to Bip, +/-5v range }
   port[base+2] :=  $30;

   clrscr;
   writeln('          Channel     Counts     Volts');
   writeln('          -------     ------     -----');


   repeat
      for channel := 0 to 15 do begin
      { Set Channel }
      port[base+2] := ((port[base+2] and $F0) + channel);

         { Reset EOC interrupt }
         port[base+1] := 0;

         { Start A/D conversion }
         port[base] := 0;

         { Wait for EOC or timeout }
         i := 0;
         while ( ((port[base+2] and $80) < $80) and (i <= 1000) ) do
            i := i + 1;

         { if timeout display error and exit program }
         if (i > 1000) then begin
            writeln('Error: Timeout on channel');
            exit;
         end; { end if }

         { Get count data }
         counts := port[base];

         { Scaling 5v range on 8 bit device = 0.039 volts/count }
         volts  := (counts - 128) * 0.039;

         { Show data }
         writeln(channel:14, counts:12, volts:12:3);
         end; { end of for channel }

      writeln('             Press any key to exit program');
   until (KeyPressed)  { end repeat }

end. { end of main }