| Author |
Message |
Guest
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 Posted:
Wed Nov 23, 2005 7:16 am Post subject:
How can I "record" and "playback" an RF signal? |
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Hello all,
Pardon a question from a DSP and electronics ultra-novice, but I've
always had great luck with this forum. Please note that when I took
about a PC, I mean a Windows 2000 based platform.
I have several robots that use consumer IR for their remote controls.
I was able to find a USB device called the UIRT that can record
(learn) infrared signals and play them back; so I can now control those
IR based robots from an open source computer program I wrote.
I recently bought an animatronic puppet that has a remote control that
uses RF to transmit movement commands to the puppet. I want to have
the same capability with the new puppet and it's RF based remote
control, that I do currently with IR based robots.
INPUT SIDE: What would be the easiest way to capture (record) the RF
signals from the remote and get them into a format that I can store on
my computer? Is there a known PC compatible A/D device I can buy that
does this already? If not, are there components that are close to what
I need that will give me a jumpstart on building something?
OUTPUT SIDE: Once I have a method for capturing and storing the RF
signals for each puppet movement, how can I "play them back"? If it's
a standard RF transmission situation, what's a convenient PC
compatible device that will allow me to play back (transmit) the RF
signal as needed?
I'm hoping of course for something that has actual Windows compatible
drivers and a good solid manual with examples. If not, I'll take what
I can get.
Any suggestions, or better yet, links to vendor sites and the model
name of the device(s)?
Thanks. |
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Jerry Avins
Guest
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| Posted:
Wed Nov 23, 2005 8:13 am Post subject:
Re: How can I "record" and "playback" an RF signal? |
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robert.oschler@gmail.com wrote:
| Quote: | Hello all,
Pardon a question from a DSP and electronics ultra-novice, but I've
always had great luck with this forum. Please note that when I took
about a PC, I mean a Windows 2000 based platform.
I have several robots that use consumer IR for their remote controls.
I was able to find a USB device called the UIRT that can record
(learn) infrared signals and play them back; so I can now control those
IR based robots from an open source computer program I wrote.
I recently bought an animatronic puppet that has a remote control that
uses RF to transmit movement commands to the puppet. I want to have
the same capability with the new puppet and it's RF based remote
control, that I do currently with IR based robots.
INPUT SIDE: What would be the easiest way to capture (record) the RF
signals from the remote and get them into a format that I can store on
my computer? Is there a known PC compatible A/D device I can buy that
does this already? If not, are there components that are close to what
I need that will give me a jumpstart on building something?
OUTPUT SIDE: Once I have a method for capturing and storing the RF
signals for each puppet movement, how can I "play them back"? If it's
a standard RF transmission situation, what's a convenient PC
compatible device that will allow me to play back (transmit) the RF
signal as needed?
I'm hoping of course for something that has actual Windows compatible
drivers and a good solid manual with examples. If not, I'll take what
I can get.
Any suggestions, or better yet, links to vendor sites and the model
name of the device(s)?
|
I assume it's not the RF itself that you need to record and play back,
but the information (modulation) carried on it. Let's check that first
before starting to discuss means and alternatives.
Jerry
--
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ |
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Iwo Mergler
Guest
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| Posted:
Wed Nov 23, 2005 5:17 pm Post subject:
Re: How can I "record" and "playback" an RF signal? |
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robert.oschler@gmail.com wrote:
| Quote: | Hello all,
Pardon a question from a DSP and electronics ultra-novice, but I've
always had great luck with this forum. Please note that when I took
about a PC, I mean a Windows 2000 based platform.
I have several robots that use consumer IR for their remote controls.
I was able to find a USB device called the UIRT that can record
(learn) infrared signals and play them back; so I can now control those
IR based robots from an open source computer program I wrote.
I recently bought an animatronic puppet that has a remote control that
uses RF to transmit movement commands to the puppet. I want to have
the same capability with the new puppet and it's RF based remote
control, that I do currently with IR based robots.
INPUT SIDE: What would be the easiest way to capture (record) the RF
signals from the remote and get them into a format that I can store on
my computer? Is there a known PC compatible A/D device I can buy that
does this already? If not, are there components that are close to what
I need that will give me a jumpstart on building something?
OUTPUT SIDE: Once I have a method for capturing and storing the RF
signals for each puppet movement, how can I "play them back"? If it's
a standard RF transmission situation, what's a convenient PC
compatible device that will allow me to play back (transmit) the RF
signal as needed?
I'm hoping of course for something that has actual Windows compatible
drivers and a good solid manual with examples. If not, I'll take what
I can get.
Any suggestions, or better yet, links to vendor sites and the model
name of the device(s)?
Thanks.
|
Robert,
while possible, you'll need very expensive kit to record and
playback the RF signal itself. A PC with a fast hard drive
and a sufficiently fast ADC could just about make it at the
traditional ~27MHz remote frequencies. Forget Windows.
If your toy is relatively new, you'll find that it probably
uses RF in the ~400MHz band, for which you would need the kind
of kit they use at the large particle accelerators. :^)
Of course, all this is unnecessary overkill, as the actual
bandwidth of the signal is only a few KHz at best.For instance,
your infrared recording device doesn't actually record the
infrared light and it may or may not record the 40KHz carrier.
Your best bet is to take the remote apart and wire up the
controls (butons, whatever) to the PC.You claimed not to
know much about electronics, so something like this may help:
http://www.ontrak.net/ADU208.htm
Kind regards,
Iwo |
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glen herrmannsfeldt
Guest
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| Posted:
Sun Nov 27, 2005 1:16 am Post subject:
Re: How can I "record" and "playback" an RF signal? |
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Iwo Mergler wrote:
| Quote: | robert.oschler@gmail.com wrote:
|
(snip)
| Quote: | I have several robots that use consumer IR for their remote controls.
I was able to find a USB device called the UIRT that can record
(learn) infrared signals and play them back; so I can now control those
IR based robots from an open source computer program I wrote.
I recently bought an animatronic puppet that has a remote control that
uses RF to transmit movement commands to the puppet. I want to have
the same capability with the new puppet and it's RF based remote
control, that I do currently with IR based robots.
|
(snip)
| Quote: | while possible, you'll need very expensive kit to record and
playback the RF signal itself. A PC with a fast hard drive
and a sufficiently fast ADC could just about make it at the
traditional ~27MHz remote frequencies. Forget Windows.
If your toy is relatively new, you'll find that it probably
uses RF in the ~400MHz band, for which you would need the kind
of kit they use at the large particle accelerators. :^)
Of course, all this is unnecessary overkill, as the actual
bandwidth of the signal is only a few KHz at best.For instance,
your infrared recording device doesn't actually record the
infrared light and it may or may not record the 40KHz carrier.
|
True but not quite fair. IR detectors are wide bandwidth for a variety
of reasons so one obviously only needs the envelope. Besides that,
there is a standard for it with standard modulating electronics.
I do know that there are devices which claim to memorize garage door
opener signals. It might be that there is now a standard frequency and
only the modulation needs to be memorized. Otherwise, it could
determine the carrier frequency and memorize that separately.
-- glen |
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Guest
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| Posted:
Sun Nov 27, 2005 9:15 am Post subject:
Re: How can I "record" and "playback" an RF signal? |
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Iwo Mergler wrote:
| Quote: |
while possible, you'll need very expensive kit to record and
playback the RF signal itself. A PC with a fast hard drive
and a sufficiently fast ADC could just about make it at the
traditional ~27MHz remote frequencies. Forget Windows.
If your toy is relatively new, you'll find that it probably
uses RF in the ~400MHz band, for which you would need the kind
of kit they use at the large particle accelerators. :^)
Of course, all this is unnecessary overkill, as the actual
bandwidth of the signal is only a few KHz at best.For instance,
your infrared recording device doesn't actually record the
infrared light and it may or may not record the 40KHz carrier.
Your best bet is to take the remote apart and wire up the
controls (butons, whatever) to the PC.You claimed not to
know much about electronics, so something like this may help:
http://www.ontrak.net/ADU208.htm
Kind regards,
Iwo
|
Iwo,
The remote has a sticker that says 27 Mhz, does that help at all? Or
is that still a massive job. Thanks for the link, I"ll have a look.
Thanks. |
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Donald
Guest
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| Posted:
Sun Nov 27, 2005 5:16 pm Post subject:
Re: How can I "record" and "playback" an RF signal? |
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robert.oschler@gmail.com wrote:
| Quote: |
The remote has a sticker that says 27 Mhz, does that help at all? Or
is that still a massive job. Thanks for the link, I"ll have a look.
Thanks.
|
What type of "remote" do you have.
Please give the manufacture and a pics would be even better. |
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Guest
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| Posted:
Tue Nov 29, 2005 9:16 am Post subject:
Re: How can I "record" and "playback" an RF signal? |
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Donald,
The manufacturer is WowWee Ltd. (made in China).
You can see a picture of it here:
http://www.flickr.com/photos/roschler/68157286/
Thanks. |
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Mark
Guest
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| Posted:
Wed Nov 30, 2005 12:15 am Post subject:
Re: How can I "record" and "playback" an RF signal? |
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you need to demodulate the 27 MHz RF signal with a receiver , record
the control info....then play it back and modulate back onto a 27 MHz
RF carrier using a transmitter....
And 27 MHz is probably only an indication of the "band of frequencies"
you will need to determine the actual frequency something like 27.123
MHz. Use a spectrul analyzer for that.
try asking over at sci.electronics.design
Mark |
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Iwo Mergler
Guest
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| Posted:
Wed Nov 30, 2005 5:17 pm Post subject:
Re: How can I "record" and "playback" an RF signal? |
|
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robert.oschler@gmail.com wrote:
| Quote: |
Iwo Mergler wrote:
while possible, you'll need very expensive kit to record and
playback the RF signal itself. A PC with a fast hard drive
and a sufficiently fast ADC could just about make it at the
traditional ~27MHz remote frequencies. Forget Windows.
If your toy is relatively new, you'll find that it probably
uses RF in the ~400MHz band, for which you would need the kind
of kit they use at the large particle accelerators. :^)
Of course, all this is unnecessary overkill, as the actual
bandwidth of the signal is only a few KHz at best.For instance,
your infrared recording device doesn't actually record the
infrared light and it may or may not record the 40KHz carrier.
Your best bet is to take the remote apart and wire up the
controls (butons, whatever) to the PC.You claimed not to
know much about electronics, so something like this may help:
http://www.ontrak.net/ADU208.htm
Kind regards,
Iwo
Iwo,
The remote has a sticker that says 27 Mhz, does that help at all? Or
is that still a massive job. Thanks for the link, I"ll have a look.
Thanks.
|
Still massive job, I'm afraid.When I said overkill I meant it.
From the looks of it, this remote is a standard proportional
control. This means that a pulse train is sent, one pulse per
channel. The 'joystick'-positions are encoded in the length of
each pulse (1ms-2ms). The whole pulse train is repeated at
about 50 times per second.
A 4-channel remote effectively repeats something like this:
__/^^^^\___/^^^\___/^^^^^^\___/^^^\___________________
Ch1 Ch2 Ch3 Ch4
Most 'professional' remote controls have a trainer connector.
It is intended to be used for teaching the piloting of
expensive air models. The idea is to use two remote controls,
one for the teacher, one for the student, with a cable between
them. The student's remote does the transmitting and the teacher
can take or release control.This is the cable:
http://www.futaba-rc.com/radioaccys/futm4400.html
http://users.belgacom.net/TX2TX/tx2tx/english/tx2txgb7.htm
http://www.rc-circuits.com/Interface Adapters.htm
Anyway, my point is that you can feed an external pulse train
into the transmitter via the cable.
This pulse train can be generated with a PC soundcard and a few
external components.
Alternatively, you could use a PC parallel port directly,
at the expense of more complex software.
There may be some commercial kit around which does this already.
I have done the opposite of what you need - flying a model in
a PC simulator, using the pulse output of a remote to control
the simulator via a trainer cable.
http://n.ethz.ch/student/mmoeller/fms/index_e.html
http://www.geocities.com/shaul_ei/SmartPropoPlus.html
Kind regards,
Iwo |
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