videoAUDIO mic-IN/OUT-headphones
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Posts: 46,084
hi all
I am working on a project (art not commerce) that requires a stamp to
converse with the audio (mic in/ headphone out) of a video camera.
1. I need the stamp to output a volume (variable thru software) that
is
compatable with the mic input on the camcorder so as to record the
audio to tape. I was planning on using a hi-res digital pot but not
to
sure about levels associated with audio (I know its different to
those
of headphones)
2. then I need the stamp to "listen" to the same volume as it is
played
back off the video tape through the headphone jack and interpret the
audio level. I was planning on using a 12bit ADC but again unsure of
the parameters of headphone levels and the AC voltage issues.
the hope is to be able to turn sensor readings into an audio signal
to
be recorded in perfect sync with video that is being simultaneously
recorded, almost a kind of data logging really. I suppose the
absolute
minimum requiremnt would be a simple audio trigger (i.e 1bit) that is
recordable and detectable but 8 bit would be really nice.
I am an animator not an audio/electrical engineer, I've managed to
get
my head around stepper control but this audio stuff is all still
kinda
confusing. Any info, diagrams, pointers in the right direction would
be
greatly appreciated.
daniel crooks
somebody@d...
p.s I tryed posting this yesterday but for some reason no luck,
hopefully this isn' a double post
I am working on a project (art not commerce) that requires a stamp to
converse with the audio (mic in/ headphone out) of a video camera.
1. I need the stamp to output a volume (variable thru software) that
is
compatable with the mic input on the camcorder so as to record the
audio to tape. I was planning on using a hi-res digital pot but not
to
sure about levels associated with audio (I know its different to
those
of headphones)
2. then I need the stamp to "listen" to the same volume as it is
played
back off the video tape through the headphone jack and interpret the
audio level. I was planning on using a 12bit ADC but again unsure of
the parameters of headphone levels and the AC voltage issues.
the hope is to be able to turn sensor readings into an audio signal
to
be recorded in perfect sync with video that is being simultaneously
recorded, almost a kind of data logging really. I suppose the
absolute
minimum requiremnt would be a simple audio trigger (i.e 1bit) that is
recordable and detectable but 8 bit would be really nice.
I am an animator not an audio/electrical engineer, I've managed to
get
my head around stepper control but this audio stuff is all still
kinda
confusing. Any info, diagrams, pointers in the right direction would
be
greatly appreciated.
daniel crooks
somebody@d...
p.s I tryed posting this yesterday but for some reason no luck,
hopefully this isn' a double post
Comments
I am working on a project (art not commerce) that requires a stamp to
converse with the audio (mic in/ headphone out) of a video camera.
1. I need the stamp to output a volume (variable thru software) that
is compatable with the mic input on the camcorder so as to record the
audio to tape. I was planning on using a hi-res digital pot but not
to sure about levels associated with audio (I know its different to
those of headphones)
2. then I need the stamp to "listen" to the same volume as it is
played back off the video tape through the headphone jack and
interpret
the audio level. I was planning on using a 12bit ADC but again unsure
of the parameters of headphone levels and the AC voltage issues.
the hope is to be able to turn sensor readings into an audio signal
to be recorded in perfect sync with video that is being
simultaneously
recorded, almost a kind of data logging really. I suppose the
absolute minimum requiremnt would be a simple audio trigger (i.e
1bit)
that is recordable and detectable but 8 bit would be really nice.
I am an animator not an audio/electrical engineer, I've managed to
get my head around stepper control but this audio stuff is all still
kinda confusing. Any info, diagrams, pointers in the right direction
would be greatly appreciated.
daniel crooks
somebody@d...
p.s I tryed posting this yesterday but for some reason no luck,
hopefully this isn' a double post
>hi all
>
>I am working on a project (art not commerce) that requires a stamp to
>converse with the audio (mic in/ headphone out) of a video camera.
>
>1. I need the stamp to output a volume (variable thru software) that
>is
>compatable with the mic input on the camcorder so as to record the
>audio to tape. I was planning on using a hi-res digital pot but not
>to
>sure about levels associated with audio (I know its different to
>those
>of headphones)
>
>2. then I need the stamp to "listen" to the same volume as it is
>played
>back off the video tape through the headphone jack and interpret the
>audio level. I was planning on using a 12bit ADC but again unsure of
>the parameters of headphone levels and the AC voltage issues.
>
>the hope is to be able to turn sensor readings into an audio signal
>to
>be recorded in perfect sync with video that is being simultaneously
>recorded, almost a kind of data logging really. I suppose the
>absolute
>minimum requiremnt would be a simple audio trigger (i.e 1bit) that is
>recordable and detectable but 8 bit would be really nice.
>I am an animator not an audio/electrical engineer, I've managed to
>get
>my head around stepper control but this audio stuff is all still
>kinda
>confusing. Any info, diagrams, pointers in the right direction would
>be
>greatly appreciated.
>
>daniel crooks
>somebody@d...
>
>p.s I tryed posting this yesterday but for some reason no luck,
>hopefully this isn' a double post
Actually a triple post ... but who's counting <smile>.
Wish I could help you, but I can't. Others HAvE responded, however.
Are you sure you have your eGroups options set up correctly ? You can
recieve responses one of two ways:
1. By logging on to the website at eGroups, or
2. Via e-mail.
This option must be set correctly to receive responses; even you own !
Hope that helps
Bruce Bates
Audio level at a mike input should be in the 1~10mV range. Recorders use
AGC, so it's not usually practical to encode data as amplitude modulation.
Playback audio level is about 100~200mV from a line output, perhaps 10
times that much from an earphone output.
This topic was discussed here recently. I think the consensus of opinion
was that low-speed modems work best, but all the old favorite modem chips
have gone the way of the Dodo bird. Can somebody correct me on this?
Here's a couple of other possibilities for recording digital data: [noparse][[/noparse]1] Use
DTMF signaling. The BS2 can output DTMF tones directly, but you need a DTMF
receiver chip to decode them at playback time. These seem to be readily
available. [noparse][[/noparse]2] Make an FSK modem. The transmit circuit just has to generate
one of two stable audio frequencies on demand. The receive circuit has to
discriminate between two tones reliably. This can be done with PLL chips,
dual bandpass filters, slope detection, pulse width measurement, etc.
>I am working on a project (art not commerce) that requires a stamp to
>converse with the audio (mic in/ headphone out) of a video camera.
>
>1. I need the stamp to output a volume (variable thru software) that
>is compatable with the mic input on the camcorder so as to record the
>audio to tape. I was planning on using a hi-res digital pot but not
>to sure about levels associated with audio (I know its different to
>those of headphones)
>
>2. then I need the stamp to "listen" to the same volume as it is
>played back off the video tape through the headphone jack and
>interpret
>the audio level. I was planning on using a 12bit ADC but again unsure
>of the parameters of headphone levels and the AC voltage issues.
>
>the hope is to be able to turn sensor readings into an audio signal
>to be recorded in perfect sync with video that is being
>simultaneously
>recorded, almost a kind of data logging really. I suppose the
>absolute minimum requiremnt would be a simple audio trigger (i.e
>1bit)
>that is recordable and detectable but 8 bit would be really nice.
>I am an animator not an audio/electrical engineer, I've managed to
>get my head around stepper control but this audio stuff is all still
>kinda confusing. Any info, diagrams, pointers in the right direction
>would be greatly appreciated.
Mike Hardwick, for Decade Engineering -- <http://www.decadenet.com>
Manufacturer of the famous BOB-II Serial Video Text Display Module!