Modem - Dtmf Digts Detection!

[KittiAnand]

Hello,

I have to develop an application which is based on MODEM communication. The program requirements are .

1. I have to detect an incoming call.
2. I have to answer the call with a prerecoreded .wav file.
3. And I have to detect subseequent DTMF key presses to let the
user select among various options.

I have gone through various AT COMMAND references. I found that , I can detect an incoming call, ofcouse it is easy. But I am not sure about remaining two steps. Particularly FOR DETECTING DTMF TONES I COULDN'T FIND ANY AT COMMANDS!.

I know a little about TAPI. But I am sure that the above things can be done through TAPI. But I have to go for a long run! I want avoid TAPI if possible at all.

So please let me have a clear picture! Thank you.

If Any URLS? please!

[GremlinSA]

Hello,

I have to develop an application which is based on MODEM communication. The program requirements are .

1. I have to detect an incoming call.
2. I have to answer the call with a prerecoreded .wav file.
3. And I have to detect subseequent DTMF key presses to let the user select among various options.

So please let me have a clear picture! Thank you.

If Any URLS? please!

Okay you got No1 your self..

2)... you can use the Modem Wave device to play back a pre-recorded wav file...

3).. this is a bit more difficult.. there's alot of hardware available.. but i'm sure you can use some audio comparator code to detect the DTMF codes...

Hope this helps..

Gremmy....

[KittiAnand]

Thank you Gremlin.

But still few things are not clear.

For detecting DTMF tones you are talking about some external hardware other than MODEM isn't it? Is it not possible to detect DTMF with MODEM alone?

First let me know weather the previously asked things can be done with AT COMMANDS alone?

Hope you extend your patience a little and reply me with more key strokes!

Thank you.

[GremlinSA]

I'll try to clear things up a little...

Unless the modem specifficaly has DTMF detection, (Details for this will be in the Modem user manual), you will either need a external DTMF Detection, or use the Modem wave device to capture the tones and use software to detect it.

Using the AT commands you can set the mode's that the modem requires, but most of what you need cannot be done via AT commands alone...

Hope this helps...

Gremmy....

[dglienna]

My laptop's modem recognizes when you press a key, and prints the key out in a terminal window. CVMichael has done a lot with sound detection. Check out his posts at VBForums.com

[GremlinSA]

My laptop's modem recognizes when you press a key, and prints the key out in a terminal window. CVMichael has done a lot with sound detection. Check out his posts at VBForums.com

Let me Guess..

Your modem has DTMF Control printed on it, and the user Manual has the details of it... And you got it with in the last year..


Gremmy...

[dglienna]

Nope. Laptop is about 3 years old. I was testing CV's code to play sound thru the modem, and found out (using HyperTerminal) that after I called it from another line, and typed ATA for answer, that when I punched a key, it showed up in the terminal window. I was kind of surprised. I have an HP Laptop - Pavillion 5400ze with a built in modem.

[GremlinSA]

Nope. Laptop is about 3 years old. I called it from another line, and typed ATA for answer, that when I punched a key, it showed up in the terminal window. I was kind of surprised.

Hmmmm.. Hp. have nothing to say about DTMF detection on there site.. Very strange..

Most contact i've had with DTMF detection on a modem was a PCMCIA card that has in bold letters.. DTMF Control , Mnfc.. ~ Jan 2005. (And never even tested this out.. )

Hmmm.. I got a bunch of 56K Duxbury's, I'll test them for DTMF Detection tomorow..

Now if KittiAnand has a modem with builtin DTMF, then #3 is sorted (By itself as well..) If, not maybe head out and try to find one with DTMF..

[dglienna]

I think the key is having a Voice Modem. I didn't get any answering machine software, but I assume that the modem is capable.

[GremlinSA]

I think the key is having a Voice Modem. I didn't get any answering machine software, but I assume that the modem is capable.

Try a quick check.. In the Device manager, under Sound, Video and Game controllers, check if you got a Modem Wave Device.

I can't play around with the server tonight, I knocked us off ADSL earlier and the wife was not impressed.. Then my mom came through and asked if the server was offline because she'd like to send some Emails... So tomorow, before everyone wants to go online I can check ...

It'll be interesting to see how easy (or difficult it) would be to write a simple answering machine.. (and remote system activator..)
Say like Option 1 Read me my email.. (I got code to do that)
Option 2 Reply to email (Using voice recognition to type)
Option 4 Play Back Voicemails..
.. Etc..

This now has realy got me thinking...

Gremmy...

[dglienna]

CV developed something that interprets DTMF tones, but I realized that the modem responds to key tones.

I just looked, and I don't have a DTMF device under Sounds. Under Modems, I have my Conextent (sp?) 56K AcLink, which is onboard. Open up Hyperterminal, set it to your com port, and call it from another number. When you type ATA, it should respond to keypresses. There are some commands that I could look up if you want. I don't want to post his code. Maybe you could PM him, and ask him to register here?

[KittiAnand]

Thank you both of you.

dglienna,

as you said, if my modem is capable of detecting of DTMF, does it do by default or do we have to set it's mode to respond to DTMF? What about your modem?.

any how,I will be back after finishing my Modem manuals!

thank you.

[GremlinSA]

Arrg.. Got a urgent email, and need to do some serious work.

But i will fiddle with this sometime today.. Will post when have clearer details on how it all works..

[GremlinSA]

Well i found the time to play with this and have a few details and a clearer picture..

I've now played around with:

A) My PC with External (SERIAL) Duxbury 56K Flex - Voice/Fax/Data

B) Client PC with Internal (PCI) Conexant 56k - Voice/Fax/Data

C) Client Laptop with (PCMCIA slot) 3Com Lan + 56K cardbus modem - Voice/Fax/Data

The three types of modems all work on sligtly diferent principles, mostly due to the diference in the connetion types..

Only the PCI has a Modem Wave Device, I'm guessing they did this because it's a permanent conneted device.. PCMCIA and Serial can be hot unplugged and plugged..

Also i Logged the Serial port while using a Modem Voice mailbox system, I've attached the Log, It gives a good clue as to which AT commands are used..

This should now give you all the details you require.. ..

If you need help to decode the log let me know.. In the meantime, I'm also fideling with it inbetween...

Hope This Helps..

Gremmy..

[dglienna]

Take a look at this page, for AT commands.

http://vocpsystem.com/install_modems.php?mode=function