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DTMF detector for home automation

dtmf detector

Scienceprog has posted how-to build a DTMF tone detector. DTMF are the standard sounds used in tone dialing. Plugging this circuit into your phone line you can decode the all the tones on the line back into their original number form. This would be useful for issuing commands to a home automation system or any other device that you wanted dial-in access to.

Comments

  1. mom/dad says:

    this was a really nice howto, i really enjoyed reading it because it was so great, but tho he didnt mention that telefones were invented by charls dickens, (capital letters) and that sony invented serriall ports 2 years ago!!!!!oneeleven(captial letters end)
    i know i am rite so just stfu

  2. polar.bear6@gmail.com , you post the most worthless comments.

  3. werejag says:

    On March 10, 1876, in Boston, Massachusetts, Alexander Graham Bell invented the telephone.

    also sony didnt invent serial ports, serial ports have been around since the first days of computers.

    so please stop making yourself look stupid.

  4. tiuk says:

    eliot – posting his email for spammers to pick up is the ultimate justice, you rock.

  5. strider_mt2k says:

    Great work!

    A few years ago I built a wheeled ROV.
    It’s primary control system is a standard RC unit, but it’s secondary system utilizes DTMF tones sent over FRS radios to operate a three-camera switcher and the zoom/focus/iris of an onboard high-resolution color camera.
    (Admittedly I wimped out and obtained an off-the-shelf DTMF controller.)

    DTMF is great to use for this kind of stuff.
    A cheap and basic DTMF encoder was found in a yard sale portable auto-dialer.
    I just wired the audio into the mic connections on the headset with a momentary switch.

    It’s old news at this point, but “probe II sg” is still intact, though currently in mothballs in a closet.
    Do a google search for “probe II sg” for details from the past. ;)

  6. TJ says:

    Interesting, but couldn’t this be done in software a lot easier?

    If you have a home automation system, the heart of it is more than likely a computer anyway.

  7. Tired2 says:

    Anyone seen that simpsons where homer get the autodialer and starts a pyramid scheme? its a good one.

    On a side note, I saw some show that showed this old school hella old electrical engineer that had his entire house wired to do TONS of shit… he used all dtmf stuff on an analog phone to control everything. The coolest thing was a tube system, and one of the tubes went to a big huge container for beer cans.

  8. hackdude says:

    lol thanks alot eliot, i just sent the spammer 100k of spam and added his mail at gayporn sites lol! thanks for taking care of spammers eliot, you rock!

    [this message was also from polar.bear6@gmail.com -Eliot]

  9. amonkey says:

    is there no ban system?
    also, i’m working on some home automation stuff,
    but i never thought of having a tube system.
    a remote for cold drinks delivered straight from the fridge would be so great that it might possibly be awesome. time to get googling. i’m thinking lego’s for the loading system.

  10. Jerb says:

    For HackDude:

    Please, practice basic grammar. Every post you make hurts you more, you simply digging yourself into a hole. Do not even bother arguing on the internet, no one wins (what was that image that went around for a while, “arguing on the internet is like the Special Olympics, even if you win you

  11. Vik Olliver says:

    Anyone else making DTMF decoder chips? Preferably ones that are still in production…

    Vik :v)

  12. nullset says:

    For information on doing DTMF/other tone detection efficiently, look up the Goertzel algorithm. Linky:
    http://www.embedded.com/showArticle.jhtml?articleID=9900722

  13. Andy says:

    Hey guys I love your site, and Im well aware that the internet is a global source for information, I was startled to see the dtmf walk through cause this is what terroists use to initiate there IEDs that are killing so many soldiers in Iraq. I just think that it would be prudent to watch what yall put on yalls web site. Like I said I love yalls site, but this one just got me being as how I have to work with these almost everyday. Thanks

  14. dylan willemsa says:

    ooh, snap

  15. Nanners says:

    The link to this article appears to have gone dead, do any mirrors exist for it?

  16. Scienceprog says:

    Sorry guys. My web-page database crashed. Good news I have backup. Little bit of patience and site will be on again.
    Sorry for this.

  17. Scienceprog says:

    Site is ON again. Thanks God i have made a backup yesterday.

  18. bogphanny says:

    “I was startled to see the dtmf walk through cause this is what terroists use to initiate there IEDs that are killing so many soldiers in Iraq.”

    And with a comment like that, I’m sure you have just inspired a few more…

  19. strider_mt2k says:

    andy

    Yes let’s limit information on the chance that someone will use it for evil.

    Better not discuss rocks either since someone might pick one up and bash your misguided brain out with one.

    Let the geology web sites know about that!

    Anyone that desires liberty and security deserves neither. -Ben franklin.

    -Not to mention that this stuff has been common knowledge since DTMF was developed, so please for the love of ghod _try_ to have a clue what you are talking about before you embarass yourself making dumb statements like you did right there.

  20. werejag says:

    Andy

    how about you stop being a moron. we will not censor ourself becuase you have a half backed idea on what an ied is.

    cell phones, simple radios, wires are common trigger devices and i will not censor that info either.

    I just think that it would be prudent to watch what you say andy. Like I said we might be right next to you waiting to DTMF hurt you.

    praise allah
    praise jesus
    praise knowledge

  21. werejag says:

    Andy

    how about you stop being a moron. we will not censor ourself becuase you have a half backed idea on what an ied is.

    cell phones, simple radios, wires are common trigger devices and i will not censor that info either.

    I just think that it would be prudent to watch what you say andy. Like I said we might be right next to you waiting to DTMF hurt you.

    praise allah
    praise jesus
    praise knowledge

  22. jarechiga says:

    You can try the MT8870 it does not require any code from the uControler, it just passes the decoded signals as they come in.

    Am using it in a payphone system to detect the dialed number, am just having trouble finding a way to detect my coins, if u have any ideas i will be checking this post.

  23. strider_mt2k says:

    jarechiga, google “phone phreaking”
    People used to(?) scam pay phones by reproducing the tones created when the coins registered in the pay phone.
    I know those folks could make the tones, _somebody_ has to have info into detecting those tones as well.

    Praise knowledge
    Praise wisdom

  24. trebuchet03 says:

    andy

    I know its a bit late… but show me where censorship from one media has prevented something from happening. Information has saved more fingers, arms, legs and lives than censorship ever will (sometimes with a side effect of bigger ego’s and superiority complex – just ask why the programming community won’t unionize :p).

    Lets stop selling pens because some kid 12 year old killed his parent in his sleep by jamming it into his ear (ya, that actually happened not too far away).

    There’s a reason busses are in operation, plane’s are flying and we post information in public domain… WE are not fueled by fear and WE will not let someone else steal our security.

    its time to adjust your tinfoil hat ;)

  25. dylan willemsa says:

    doot bleep beep doot…blam

  26. ankush says:

    the site is down i believe. i have tried for the past two days to view it. could someone who’s seen the site answer me: this device decodes the tones into their digits, but how does the output work? serial port connection or what? i am just too curious to wait for the site to get fixed!

  27. hackdude says:

    it actually hurts to read these comments now

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