Hi guys, preparing to make some project

Discussion in 'The Projects Forum' started by BigShoe, Aug 15, 2011.

  1. BigShoe

    Thread Starter New Member

    Jan 16, 2009
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    0
    Hi friends,
    I'm gonna start a project of a remote controlling interface, and what I need from you is just few suggestions.
    What I want to do is a remote that is based on a phone call.
    That means that when I call to the phone number, after few signals it answers automatically and I control things connected to the circuit by clicking the numbers on the phone. like if I push 1, it will send "1" logic to some defined port, when I push number two, it sends "1" logic to another port and so on.

    Could you give me some direction of thought?

    Thanks in advanced and sorry for my bad English,
    Sincerely yours, Ami.
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,094
    3,033
    Welcome to the AAC forum.

    I don't think this is really a circuit project, as most of what you need is software.

    I can imagine the right custom app on an Android phone would be capable of receiving your call as you described, and then sending out commands to a bluetooth device (your circuitry) based on what the phone "hears" from you. Until you find a way to get the app written, I don't think there's much value in working on the downstream hardware components.

    Just remembered, there is good software already for using your smartphone as a remote control. It might be helpful to review such things.
     
  3. BigShoe

    Thread Starter New Member

    Jan 16, 2009
    5
    0
    well, thanks.
    and about what you think.
    I'm not talking about a cellphone, however a regular home line phone.
    and for that, I need at most to work with hardware and less with program, although indeed, it's needed there too.

    So what about that?
     
  4. BigShoe

    Thread Starter New Member

    Jan 16, 2009
    5
    0
    also found information about the sound's frequencies.
    I need advices of what to do between the phone line and the A/D.
     
  5. BigShoe

    Thread Starter New Member

    Jan 16, 2009
    5
    0
    anybody? please?
     
  6. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    Hi Ami,

    What you are looking to build is a DTMF or dual-tone multifrequency decoder. Phones use DTMF to generate the tones you hear when you press a button. They make ICs that can do this I believe.

    Ramsey makes a kit: http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=TT7.

    The instructions include the parts used (including the DTMF decoder IC) and the circuit on a PCB: http://www.repeater-builder.com/ramsey/ramsey-touch-tone-decoder-tt7.pdf

    As far as having the phone pick up when you call, you can use a cheap answering machine to pick up then connect to a DTMF decoder circuit (perhaps through the speaker), either the Ramsey or one you build yourself.

    Hope this helps.
     
  7. BigShoe

    Thread Starter New Member

    Jan 16, 2009
    5
    0
    Ok,
    I will explain myself again.
    My point is to build a device that will be connected directly to the land-phone line and will know how to understand the DTMF. That's all.
    I don't want to use nothing that is already prepared.
    I want to built all the thing from it's beginning.
    That's all.
    Now my problem in this case is to know how to decode the data that comes through the land phone line. how to make a circuit that will understand all the keys' sounds.
    All the rest I know how to do, an automated answering, and the others.

    Please help.
     
  8. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    Ami,

    I understand if you don't want to buy or build a kit, but you can reverse engineer the design using the DTMF IC they use and come up with your own design to use as you please.

    So, do you want to do this with discrete parts only? If yes, look up DTMF decoder IC on Google and this forum.

    Or, do you want to do everything in software with a microcontroller? If yes, this should help: http://www.electro-tech-online.com/...ding-using-only-pic-no-tone-decoder-chip.html.
     
  9. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Is anyone else aware that this would make a great remote IED trigger?

    Mods, please!
     
  10. wayneh

    Expert

    Sep 9, 2010
    12,094
    3,033
    A great number of things discussed here could be used for nefarious purposes, just as can be a butcher's knife from my kitchen.

    It's simple; knowledge in the wrong hands is dangerous. But I don't know how a teacher might imagine what a student will do with the knowledge he learns. If the student only wants to take-off planes and not land them, OK, that's a red flag. This OP's description isn't that obvious, but it is always nice to know "why". My first boss, who was otherwise a total a-hole, said you should always ask why. Good advice.

    If these forums are so buttoned down that you can't discuss replacing a dome light in your car, maybe every question posted here should be required to explain "why". Tell us what you're up to - within reason - or no more discussion. It probably would improve the efficiency, with less folks here guessing at what a poster really wants to accomplish.
     
  11. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,535
    Lots of things can make a good IED trigger, this one doesn't raise any flags for me. Now days people making IEDs are professional, they don't need to come to this forum for that kind of help. They have factories making the dern things in big numbers.
     
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