Subject: Re: Single / Multitone Detector (Not DTMF)
Date: Mon, 20 Jan 2003 12:37:00 +1100
NNTP-Posting-Date: Mon, 20 Jan 2003 01:36:55 +0000 (UTC)
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Why not use a remote control, with code hoping if required, as used on
burglar alarms and door openers.
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Watson 'Atto Parsec' Name wrote in message ...
>In article ,
>> Thanks for suggestions; I'm looking at some of the
>> selcall stuff.
>> The 567 is one-tone-at-a-time and I have made stuff
>> with several of them in the past; they aren't the
>> most stable possibility, but would probably work.
>> I was hoping that a decade of silicon development had
>> some up with my fantasy chip :-)
>I've used the 567 PLL, and it's kind of slow to lock if you use the
>value of caps that they show in the data sheets. I've reduced those,
>but then it has a wider bandwidth. But it's a good chip for picking
>tones out of the noise.
>> 1: I have several inputs from handheld FRS and/or GMRS
>> radios, which have several 'calling tone warble'
>> options, one of which sounds like a typical electronic
>> phone. I was hoping to be able to pick two tones
>> from each of these, and to be able to identify which
>> user was calling. I MIGHT be able to pick one tone,
>> and detect the time-domain pattern. Hmmm.
>> 2: Maybe I have just carrier-detect from handheld radios.
>> 3: I have DTMF from amateur radio and the phone system.
>> My hope is to come up with a PIC based system that I can use
>> and which might be able to be used by others for similar
>I think that with fast tone bursts, you're probably better off using
>something like a prefilter to let the whole band of tones thru, then
>clip them and then look at them with your microcontroller and firmware.
>If the tones are consecutive with no gaps between, that should make it
>more resistant against false 'talkoff'.
>> My application is for access to my home control system and
>> communications systems from FRS radios used by family members,
>> and from the phone system. My most immediate need is to
>> be able to turn on the "road" lights when arriving late at night.
>> But once I get into the system, lots is possible.
>I think this would be a good job for a garage door remote or the X-10
>(yuck, damn pop-up ads). Also you could probably install a security
>light with the PIR sensor that detects people or cars, and the lights
>would turn on automatically for a minute or two. And where I live, in
>So. Cal, the security lights were dirt cheap at Wal-Mart, I guess
>because the power companies want to get people to install them to save
>> This time of year we end up often walking down the hill thru the snow
>> from 800 to 1200 feet, depending on what got plowed by whom. The
>> town doesn't plow OUR road. I have 120V lights up covering most of
>> the first 800 feet, but I hate to have them on from sunset until
>> EVERYONE gets home, especially with older kids who may not get home
>> this night at all...
>> The rest of the logic and interfacing will be OK, but this funny
>> tone-detect stuff is problematic right now...
>> Thanks for the help!
>> > Are you stuck with specific tones? or can you make
>> > them anything you want.
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