USB-UIRT Forum

[Dann]

I wonder is anyone might be able to help me out. I'm using Delphi 6 on XP-Pro to work with the USB-UIRT:

Firmware Version = 1289
Protocol Version = 257
Firmware Revision Date = 3/26/2004
Config Value = 3

Everything seems to init OK, the LED flashes when I call UUIRTTransmitIR, and flashes when I press any buttons on my TV remote.

My callback function set by UUIRTSetReceiveCallback is called each time a button is pressed on the remote as well. The 2nd parameter (userData) is passed in correctly and contains the value I set from UUIRTSetReceiveCallback, but the 1st parameter (IREventStr) is returing the same data no matter what button is pressed. And, it doesn't seem to be an ASCIIZ string either.

I get (in decimal) 0 0 0 0 1 0 0 0 32 144 1 16 171 as the 13 characters no matter which button is pressed. I would expect that this data would be different for each button pressed and the 13th character would always be an ascii zero. I'm new to Delphi so I figure I'm doing soemthing dumb with regards to how I've declared the method's parameters.

Here's how the callback method is coded:

procedure TUIRT.Rcv(IREventStr: pchar; userData: longint);
var
myObj: TUIRT;
j: integer;
s: string;
begin
myObj := TUIRT(userData);
Form1.Memo1.Lines.Add(' udata='+IntToStr(myObj.udata));
s := '';
for j := 0 to 12 do begin
s := s +IntToStr(ord(IREventStr[j]))+' ';
end;
Form1.Memo1.Lines.Add(' IREventStr='+s);
end;

I set up for the callback with this call (at the end of the TUIRT.openUIRT method):

res := UUIRTSetReceiveCallback(FDrvHandle, integer(@TUIRT.Rcv), integer(self));

Any idea what I've done wrong?

Thank you very much,
Dann

[jrhees]

Dann,

Yes, you should expect to see a 12-digit ASCII string. You may want to try declaring your parameter as a String instead of PChar and see what happens...

-Jon

[Dann]

[jrhees]

Your expectations are correct, and you *dont* need to make any other calls. I still believe this is a declaration/stack problem and how parameters are passed, etc. The reason I can be sure of this is that you will *always* be passed a 12-digit ASCII hex string, and you are in fact seeing null characters and other non-ascii chars.

If you contact support@usbuirt.com I can send you a simple test app.

-Jon

[Dann]

[Dann]

[quote="Dann"]

[harm]

Hi,

I seem to have the same problem as described in this thread; but the solution is still unclear to me. Could you please (dann or jon) post a small snippet of code for the callback procedure?

Thanks in advance

[jrhees]

We had to move the callback procedure outside of the Class (basically make it a 'global' procedure).

-Jon