TTL to Line out / Line out to TTL schematic

[Victor Nowecki]

I have an IC the produces a signal / code at TTL levels that I would like to
convert to a Line out signal so that I can record the codes on my computer.
Then I'd like to play these codes, take them from the line out from my
computer or CD player and convert the level back to TTL Logic.

Anyone out there with any ideas or schematics who can direct me would be
muchly appreciated.

Thanking you in advance

Regards
Victor Nowecki

Please email me direct
e-mail at casdsys@box.net.au

 

[Tomi Holger Engdahl]

"Victor Nowecki" <casdsys@box.net.au> writes:

I have an IC the produces a signal / code at TTL levels that I would like to
convert to a Line out signal so that I can record the codes on my computer.

All you need to do for the conversion of TTL to line level signal is to
drop the signal level somewhat and put a suitable capacitor in series.

For example youi can try 4.7 kohm resistor from TTL output to
a common point. Then 1 kohm from this common point circuit ground.
Then a suitable capacitor, for example 10 uF or larger from
the common point to line output (if you use electrolytic
capacitor put it such way that + points to that common point).

This converts the TTL output signal to the signal quite comparable
to level typical to audio signal.

Rwemeber that this method does not pass the static logic state information,
juts the signal state changes information.

Other idea if the logic state is necessary is to use the TTL
outptu control to turn some auitable audio frequency oscillator
on/off (for example logic 1 = audio output on).

Here are fre idea.

Then I'd like to play these codes, take them from the line out from my
computer or CD player and convert the level back to TTL Logic.

Anyone out there with any ideas or schematics who can direct me would be
muchly appreciated.

Thanking you in advance

Regards
Victor Nowecki

Please email me direct
e-mail at casdsys@box.net.au

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

 

[Gerard Bok]

On Wed, 2 Jun 2004 12:19:42 +0930, "Victor Nowecki"
<casdsys@box.net.au> wrote:

I have an IC the produces a signal / code at TTL levels that I would like to
convert to a Line out signal so that I can record the codes on my computer.
Then I'd like to play these codes, take them from the line out from my
computer or CD player and convert the level back to TTL Logic.

Anyone out there with any ideas or schematics who can direct me would be
muchly appreciated.

If you want a more or less reliable way to retreive digital data
from an audio device you will need to convert the digital data
into some form of sound and back.

Take a look at Kansas City tapes on
http://www.alphalink.com.au/~edsa/
and you will get the idea.

--
Kind regards,
Gerard Bok

 

[CWatters]

"Tomi Holger Engdahl" <then@solarflare.cs.hut.fi> wrote in message
news:lajhdturxhz.fsf@solarflare.cs.hut.fi...

"Victor Nowecki" <casdsys@box.net.au> writes:

I have an IC the produces a signal / code at TTL levels that I would
like to
convert to a Line out signal so that I can record the codes on my
computer.

All you need to do for the conversion of TTL to line level signal is to
drop the signal level somewhat and put a suitable capacitor in series.

That won't work unless the TTL Signal is encoded correctly.

You need to tell us more about the frequency of the data and how it's
encoded. If you have a low enough bit rate you might get away with a simple
Voltage Controlled Oscillator (VCO) and a Frequency to Voltage Converter.