New in FSUIPC use

[lucasneves]

Hi everybody,

I've started today in take offsets from FSUIPC and send them to Delphi. For study, I am using the Delphi example of the SDK and trying to implement another offsets.

During tests with the IAS (offset 02BC), I am not being able to return the correct value of this offset. Comparing with FsInterrogator, my value is very diferent to the value in Fsint.

I am sending the routine that calculates the Airspeed in my program. If somebody can tell me what am I doing wrong, i'll be aprreciate. I believe I am not using some other convertion or taking the value in a wrong way.

Here is the code:

===========================================

procedure TFrmTPrincipal.MostraVelocidade;

var

dwResult : DWORD;

Velocidade: Byte;

Calculo: Double;

begin

if FSUIPC_Read($02BC, 4, @Velocidade, dwResult) then

begin

if FSUIPC_Process(dwResult) then

begin

Calculo := Round(Velocidade / 128);

stVelocidade.Caption := FloatToStr(Calculo);

end;

end;

end;

============================================================

Thanks very much!

[Pete Dowson]

During tests with the IAS (offset 02BC), I am not being able to return the correct value of this offset. Comparing with FsInterrogator, my value is very diferent to the value in Fsint.

I don't know Delphi, but this looks wrong:

Velocidade: Byte;

Considering the value you are reading is a 32-bit integer (occupying 4 bytes), don't you think one byte (8 bits) is a bit small? You do seem to know it's 4 bytes long because you have that in the Read:

if FSUIPC_Read($02BC, 4, @Velocidade, dwResult) then

Regards

Pete

[lucasneves]

Dear Pete,

At first, thanks for answering me. Do you have some example in C / C++ or another language taking this offset? I can try to write it to delphi.

Thanks again.

UPDATE: I tried to take the value using a LongInt type variable and it worked!

Thanks!

[Pete Dowson]

I tried to take the value using a LongInt type variable and it worked!

I assume a Delphi "Longint" is 32-bits, then? In most current languages I think an Int or integer is 32-bits in any case. In C/C++ you can have a "short int" too (16-bits). Some versions support "long long" for 64bits but Microsoft C/C++ seems to have special types like _int64. One of the problems in C/C++ is that types like "int" are actually of undefined length -- they are the length of a 'normal' number on the hardware being used. Hence compiler-system-defined types like _int8, _int16, _int32 and _int64.

Regards

Pete