[Asterisk-Users] Lost DTMF digits

[David Farrant]

Hi all,

I am writing a program which accepts an incoming call, plays some messages, 
accepts some DTMF digits (which make up an outgoing phone number) and then 
dials the provided number. However, the problem I am suffering is the loss 
of DTMF digits when the program is busy performing other actions. The first 
instance is in-between playing soundfiles, e.g.

##
my $ret1 = $AGI->stream_file( '/sound/dialtone', '01' );
my $ret2 = $AGI->stream_file( '/sound/welcome', 01' );
##

In the instance above the program is meant to play a half second dialtone 
and then a welcome message. If the user presses a key to start dialling 
straight away the playback stops and the digit is returned to $ret. 
Unfortunately, if someone presses a key in the half-second in-between 
messages the digit is lost.

The second instance is:

##
# grabbing DTMF digits to make outgoing telephone number
my $timeout = 3000; # 3 second timeout
while ( $wait ) {
     my $digit = $AGI->wait_for_digit( $timeout );
     if( $digit > 0 ) { # if digit is input, wait for more digits
         $digit -= 48; # making digit decimal from ascii
         $outgoing_number .= $digit;
     }
     else { # stop waiting for more digits
         $wait = 0;
     }
}
my $ret3 = $AGI->exec( 'dial', "Zap/G1/$outgoing_number" ); # dial outgoing 
number
##

In this instance once the user stops dialling for three seconds the program 
assumes the user has entered the complete number and starts dialling. If 
however, the user is just slow and has yet to input some digits, any digits 
entered while the program is trying to dial are lost. The program will 
start listening for more digits if the dial fails but it will still have 
lost the digits input during the dial.

If anyone has any idea how to capture the 'lost' DTMF digits while the 
program is busy performing other actions I would be much obliged. Even 
better would be a way to be constantly listening for DTMF digits in the 
background of the program so I could grab the DTMF presses at my leisure 
and run commands without fear of 'losing' anything.

Many thanks in advance for your help.
David Farrant