How to get the dial number from GSM module

I don't think there is one, as all that is received is a tone. You probably need a separate DTMF decoder.

Leon

Yup. AFAIK the call setup and teardown is all hifalutin digital stuff, but once the connection is made the network does its best to pretend that that ridiculously powerful computer that you're holding in your hand is just the same as a POTS phone from 1910.

So when you push that '1', your phone sends audio to the cell tower. At most, your phone tells the cell tower 'hey, the dingbat pressed the 1', and the tower makes DTMF audio. No matter what, your second phone will receive DTMF, so it's up to you to decode it.

HOWEVER: If you can figure out how to choke it out of the module, you could send text messages and it would be end-end digital. Or if your network supports it you could establish an end-end TCP/IP connection.

If you want to emulate a 1910 era phone, you are going to have to generate dial pulses.

f,

I just checked the Telit GE-863 module I'm using for a tracking application. They have AT commands for sending DTMF tones, but not for receiving them.

Leon

And possibly the crank to ring up the operator.

OK, so I exaggerated.

l stuff,

Did they have rotary pulse decoders then, or did you still have to just crank a bell and ask the Operator to connect the call for you??

-mpm

Did they have rotary pulse decoders then, or did you still have to just crank a bell and ask the Operator to connect the call for you??

-mpm

Yes they did. After the connection was established the following pulses could be fed to a rotary relay an used for whatever you wanted to control.

John G.

Dear all, thank you for your help. Now may I sum the answers, the GSM module can only receive tone information. I need a separate DTMF decoder.

In the telephone bank, when you dial the bank service number, the terminal will answer and let you press some number to select different service. I wonder how they identify the number customer dials, with a DTMF decoder?

Yes. The PABX equipment has DTMF decoding capability within it. These days, its all implemented in the same microprocessor that plays the "press 1 if you are confused" wave files and does the voice recognition.

some modems support DTMF decoding (DTMF decoding is what you want), I do not recall the command to enable it, or know if it's standardised.

Bye. Jasen

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