How connect GSM (cellular-phone) to microcontroler, reading dial-tones and dial a phonenumbers?

Are these devices and services available in the US of A ???

I'd look at hacking one of the X10 TR16A touch tone controllers below. It answers a phone call, and can decode touch tones. Once it goes off hook, you probably could talk/listen to people at the front door via a handset or mic/speaker attached to it. Probably a lot cheaper than trying to use a cell phone.

Ericsson and others make GSM nodules, with an RS232 port and the guts of a mobile phone inside. You can plug in a microphone & speaker for analog, but you can also do all the digital stuff through RS232 - dial numbers, answer calls. You can also go on the internet, do Text Messaging do Data vs Voice calls. Have a look at websites of phone companies for specs and info. I have a feeling that some mobiles can do this via a connector. The modules aren't too expensive.

A disadvantage of phones is you have to pay to keep a phone on the network, just to wait for the message to unlock your door. There are short range RF modules available which will interface to your microprocessor.

Roger

Did you consider using a bluetooth enabled phone?

What way you could use the bluetooth interface to program the GSM phone.

Deepa

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It's been a while for me, but they used to want a fortune to tell you how to run these damn things, and then they set up a protocol that was designed just to be hard to hack. I tried to figure out qualcomm phones system in 2001 and gave up, sends ten thousand bytes to do the work of 2. I ended up using mos switches to emulate the keyboard for that prototype. That was before these modules were available though.

Original posters idea of using dial tones is pretty practical. Dial tones are properly reconstructed over the abstract digital connection so that you can use your cell phone with services that use dial tones. A normal Hayes compatible PC modem can read dial tones just fine and run your automation. Teltone makes some good chips that read dial tones. You could set the phone for autoanswer, then just read the dial tones through the headset speaker outputs. For audio you could switch in a mic mounted outside the door. I couldn't get the autoanswer to work when I did this project, I can't remember why, so instead I detected the ringing noise on the fake headset speaker connection.

Kind of a neat project, good luck, I got paid for doing the one I did.

Rocky

network,

range RF

But calling without answering doesn't cost anything! ;-)

But calling without answering doesn't cost anything! ;-)

Yes I have, but there no simple way to use bluetooth with a microcontroller-chip like Pixace. Is there?