sending DTMF data, please help

[runtime]

Hello all,

Suppose I want to send the following string of data over a phone line using DTMF tones:
{@ü*38]%<

The hex of each char will be:
7B 40 FC 2A 33 38 5D 25 3C

Using DTMF I can send the tones individually, 7-B-4-0-F-C...

Now, how do I separate each hex digit, i.e: to send digit 7B first i need to send tone 7 and then tone B?

Thank you in advance
Peter

[Laurent Chouinard]

Suppose this:

int8 stuff;

//store 7b in some memory location
stuff = 7b;

//To send the left part:
output = stuff & 0xf0; //This will mask the "b" and keep the "7"
output = output >> 4; // This will shift the 7 from the high nibble to the low

send_dtmf(output); //first byte sent!

//To send the right part:
output = stuff & 0x0f;

send_dtmf(output); //second byte sent!

there you go.

Of course i'm assuming you have a function called "send_dtmf"... adjust for your needs.