Tone Reader

Thread Starter

andyman

Joined Jan 19, 2009
7
I'm looking for a 'tone reader' circuit that will read different tones (1000hz, 900hz, etc) from an audio source (line in) and return a separate On current for each tone.

Thanks,
Andy
 

Thread Starter

andyman

Joined Jan 19, 2009
7
Thanks for the info, Bertus.

Forgive my ignorance, I'm somewhat new to electronics - on the schematic you referenced - where would I connect my audio line in? The VE inputs?

Andy
 

beenthere

Joined Apr 20, 2004
15,819
The line marked "IN". +VE and -VE are the positive and negative power supply rails. Ground is common to both power supplies and to the signal.
 

beenthere

Joined Apr 20, 2004
15,819
Google it, and get the data sheet.

As another suggestion, there is the old twin-T filter that can't be beat for tight response. You can Google those, too.
 

bertus

Joined Apr 5, 2008
22,270
Hello fred_uk,

What you are doing now is hyjacking the thread.
But you can place a rectifier at the output of the filter.
Amplify the signal (and if you want send it through a comparator) and you can trigger a led.

Greetings,
Bertus
 

Thread Starter

andyman

Joined Jan 19, 2009
7
My ultimate goal here is to choreograph fireworks. I already have a wireless control box with hardware switches. I want to put tones (at least 8 different ones) on the right channel of my audio track, and feed that track to an interface which would translate the various tones into 8 different relay closures.

Andy
 

Thread Starter

andyman

Joined Jan 19, 2009
7
The audience won't hear the tones. This idea might work. I'll let you know how I make out.

Thanks for the input, guys.
Andy
 

AlexR

Joined Jan 16, 2008
732
This sounds like a job for DTMF encoder and decoder chips. They will give much better detection reliability than single tones and filters. Off hand I can't remember chip numbers but a google should throw up some likely candidates.
 

Søren

Joined Sep 2, 2006
472
I have to second (or third ;)) the notion of DTMF, as I have seen quite competent huge X-mas "decorations" made that way.

If needed, I can provide the DTMF tones as wave files, MP3 or whatever, so just the decoder will be needed.
 

Thread Starter

andyman

Joined Jan 19, 2009
7
Thanks for the offer, but I may be able to generate them myself. I have an Audio Editor (Audacity) that can generate tones as sine, square, or sawtooth wave - will that work? If so, which one?
 

Søren

Joined Sep 2, 2006
472
Hi,

I have an Audio Editor (Audacity) that can generate tones as sine, square, or sawtooth wave - will that work? If so, which one?
Audacity cannot generate DTMF (Dual Tone Multiple Frequency) and the link that Bertus gave you, cannot save the tones, as far as I can see - but you can fetch this zip with 300ms DTMF files.
I have made them at 0dB and at -6dB.
 
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