Reading from serial port returns ASCII code of character received

[Kuns]

Note: I use Visual C++ 2005

I would like to read the received character from the serial port (e.g. 'a', 'b', ...). Instead I get the ASCII code of the character I received (97, 98, ...). Here's the code I use:

//defining the serial port
System::IO:orts::SerialPort^ mySerialPort;

...

//in the function
String^ string;
cli::array<unsigned char>^ buffer;
buffer = gcnew <unsigned char>(1);

mySerialPort->Open();
mySerialPort->Read(buffer,0,1);
string += buffer->getValue(0);
MessageBox::Show(string,"Character received");

Thanks for your Help

 

[Salem]

Maybe make buffer a regular char rather than an unsigned char.

Maybe cast the result of getValue() into a char.

I'm guessing that string += only does what you want when the thing being added is a char, for everything else it invokes the 'toString' conversion for whatever type it is, then appends the result of that to your string.

Oh, and please use [code][/code] tags when posting code.


--
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.

 

[Kuns]

Hi Salem,

Thanks to your two suggestions I now am sure that the problem is the one you evoke: using string+= invokes the 'toString' conversion and gives me the ASCII code of the character.

I cannot yet find the solution:

- "Maybe make buffer a regular char rather than an unsigned char." I cannot because the mySerialPort->Read() function takes as first parameter a cli::array<unsigned char>^.

- "Maybe cast the result of getValue() into a char." Even when casting it back to a char the fact of using the string+= still puts the ASCII code of the character into string.

So my problem actually how to transform an array of unsigned char into a String?

 

[Salem]

Since your array is only 1 char long anyway, it seems a moot point to call it an array.

But anyway

char temp = buffer->getValue(0);
string += temp;

Does this still append '97' in place of 'a' ?


--
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.