PiGPIO  - Adding  GetByte  "like" GetBit
lazarus / 32-Linux

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emjtech · 2018-12-19 18:40

Hi
I need to access the GPIO fast in order to read some special hardware.
I looked into the GetBit function (attached at the end of the post for
convenience) and I so ... + (gpin shr 5) shl 2) ;
However gpin is a number from 2 to 27 (decimal) therefore the result
of that calculation will always be zero
Is there something I don't get, or I can write that line as

gpiof := Pointer(LongWord(Self.FGpio) + 52);

Thanks

//********************************************************************
***********
function TIoPort.GetBit(gpin : byte):boolean;
var
   gpiof : ^LongWord;
begin
  gpiof := Pointer(LongWord(Self.FGpio) + 52 + (gpin shr 5) shl 2);
  if (gpiof^ and (1 shl gpin)) = 0 then Result := False else Result :=
True;
end;
//********************************************************************
***********