How can I store hexadecimals inside an array? C++ MFC - c++

Question

I have to use an array of hexadecimals because I'm doing a program to communicate with a video server controller and he just understands messages in hexadecimal. I can connect the video controller with my server, but when I try to send messages using the send() function, passing an array of unsigned char that contains my information in hexadecimal, it doesn't work.
This is how I am using the array. I don't know if it is correct.
void sendMessage()
{
int retorno;
CString TextRetorno;
unsigned char HEX_bufferMessage[12]; // declaration
// store info
HEX_bufferMessage[0] = 0xF0;
HEX_bufferMessage[1] = 0x15;
HEX_bufferMessage[2] = 0x31;
HEX_bufferMessage[3] = 0x02;
HEX_bufferMessage[4] = 0x03;
HEX_bufferMessage[5] = 0x00;
HEX_bufferMessage[6] = 0x00;
HEX_bufferMessage[7] = 0xD1;
HEX_bufferMessage[8] = 0xD1;
HEX_bufferMessage[9] = 0x00;
HEX_bufferMessage[10] = 0x00;
HEX_bufferMessage[11] = 0xF7;
retorno = send(sckSloMo, (const char*) HEX_bufferMessage, sizeof(HEX_bufferMessage), 0);
TextRetorno.Format("%d", retorno);
AfxMessageBox(TextRetorno); // value = 12
if (retorno == SOCKET_ERROR)
{
AfxMessageBox("Error Send!! =[ ");
return;
}
return;
}

Answer 1

Pop quiz. What's the difference between:
int n = 0x0F;
and:
int n = 15;
If you said, "nothing," you're correct.
When assigning integral values, specifying 0x, 00 for octal, or nothing for decimal makes no difference in what is actually stored. This is a convenience for you, the programmer only. These are integral variables we're talking about -- they store numeric data only. They don't store or care about radix. In fact, you might be surprised to learn that when you assigned a numeric value to an integral variable, what is actually stored isn't decimal or hexadecimal or even octal -- it's binary.
Since you're storing these values as unsigned char, and char (unsigned or otherwise) is really just an integral type, then what you're doing is fine:
HEX_bufferMessage[0] = 0xF0;
HEX_bufferMessage[1] = 0x15;
HEX_bufferMessage[2] = 0x31;
but your question makes no sense:
Anyone knows if using an array of unsigned char is the right way to
store hexadecimals??