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'Long distance' IR remote control learning.

N

N Cook

Jan 1, 1970
0
That is going across continents.
To transfer the pulse coding of a remote control at one site to another
learnable type remote control maybe the other side of the world.
Can anyone think of a method that uses off the shelf equipment used in a
domestic environment , ie not using oscilloscopes etc.
Somehow slowing the pulse stream down enough to capture on cam-corder/pc
etc.
Would the average r/c with say a 400 KHz ceramic resonator still function
with the 400KHz one replaced with 100KHz one say.?
 
G

Geoffrey S. Mendelson

Jan 1, 1970
0
N said:
That is going across continents.
To transfer the pulse coding of a remote control at one site to another
learnable type remote control maybe the other side of the world.
Can anyone think of a method that uses off the shelf equipment used in a
domestic environment , ie not using oscilloscopes etc.
Somehow slowing the pulse stream down enough to capture on cam-corder/pc
etc.
Would the average r/c with say a 400 KHz ceramic resonator still function
with the 400KHz one replaced with 100KHz one say.?

Look up LIRC (linux infrared remote control).

For example, I can type remotecontrol.p (a PERL program) on any computer
on my network, and the satellite receiver downstairs changes channels.
I can also control a VCR and Stereo Recevier.

If the remote control you want to duplicate is not listed, you need
to use a receiver to decipher the codes. You can make one yourself or
buy one for about $30.

The remote transmitter can be as simple as an IR LED and a resistor. Since
my equipment faces a window, instead of trying to make a unit bright enough
to overcome the sunlight streaming in, I just made three of them connected
to the same serial port and placed an LED next to each sensor.

The remote computer does not have to be much, it needs to run Linux,
have some sort of network connection and a serial port.

Geoff.
 
J

jasen

Jan 1, 1970
0
That is going across continents.

there's a open remote project on sourceforge, i'm not siure what they use to
record, I think either IRDA or some cheap hardware.
To transfer the pulse coding of a remote control at one site to another
learnable type remote control maybe the other side of the world.
Can anyone think of a method that uses off the shelf equipment used in a
domestic environment , ie not using oscilloscopes etc.
Somehow slowing the pulse stream down enough to capture on cam-corder/pc
etc.
Would the average r/c with say a 400 KHz ceramic resonator still function
with the 400KHz one replaced with 100KHz one say.?

probably.

the pulse rate is ~40Khz most PCs can handle that.
 
N

N Cook

Jan 1, 1970
0
jasen said:
there's a open remote project on sourceforge, i'm not siure what they use to
record, I think either IRDA or some cheap hardware.



probably.

the pulse rate is ~40Khz most PCs can handle that.

I don't own a web-cam but anyone know what would happen if
you replaced the IR LED with a diffused red LED and shone it close to a web
cam.
Starting with a normal IR R/C with its original crystal and normal pulsed
output of 25uS per pulse and 20 pulses per bit of data. Would that produce a
resolvable video stream that could be sent via internet and assuming a wide
enough acceptance spectrum of the receiving phototransistor/diode of a
learner type universal r/c straight off a pc monitor in a dark room.
 
T

Tim Auton

Jan 1, 1970
0
N Cook said:
I don't own a web-cam but anyone know what would happen if
you replaced the IR LED with a diffused red LED and shone it close to a web
cam.
Starting with a normal IR R/C with its original crystal and normal pulsed
output of 25uS per pulse and 20 pulses per bit of data.

Webcams can usually see near-IR reasonably well anayway.
Would that produce a
resolvable video stream that could be sent via internet and assuming a wide
enough acceptance spectrum of the receiving phototransistor/diode of a
learner type universal r/c straight off a pc monitor in a dark room.

No. Webcams can manage perhaps 30fps. You'd need something much, much
faster.


Tim
 
G

Geoffrey S. Mendelson

Jan 1, 1970
0
N said:
Starting with a normal IR R/C with its original crystal and normal pulsed
output of 25uS per pulse and 20 pulses per bit of data. Would that produce a
resolvable video stream that could be sent via internet and assuming a wide
enough acceptance spectrum of the receiving phototransistor/diode of a
learner type universal r/c straight off a pc monitor in a dark room.

I did that in the 1980's with an IR photodiode, an LM324 op amp and an
IR LED. Another thing I should of patented.

Geoff.
 
C

Chris Jones

Jan 1, 1970
0
N said:
That is going across continents.
To transfer the pulse coding of a remote control at one site to another
learnable type remote control maybe the other side of the world.
Can anyone think of a method that uses off the shelf equipment used in a
domestic environment , ie not using oscilloscopes etc.
Somehow slowing the pulse stream down enough to capture on cam-corder/pc
etc.
Would the average r/c with say a 400 KHz ceramic resonator still function
with the 400KHz one replaced with 100KHz one say.?

An old PC (even a 386) running only a DOS application with all the
interrupts turned off can sample the printer port to memory at maybe 1MHz
and could probably do your task if you attach a photodiode and comparator
of some sort, with a reasonable frequency response, or cheat and open the
remote to get the logic signal out directly. Given sufficient
determination, this might also be achievable with a modern computer running
some sort of windows too, at least in theory. Since the modulation is only
about 40kHz on most remotes, you might be able to find some sound card with
Audiophool grade sample rates like 192kHz, which might also work, with a
suitable photodiode or connection to the LED. As you suggest, slowing down
the clock of the remote would make things easier, and I think it would
work. You could then use a tape recorder, sound card or whatever
non-compressed audio recording device you want. If you slow it down too
much then you might want to put some current limiting in the LED as they
run them above the continuous current rating, and at a sufficiently low
clock rate the LED may burn out.

I think it might be hard to use a VCR and photodiode to record the signal
because having sync pulses might prevent you from capturing enough
continuous signal from the remote. If you can get a VCR to record without
h-sync pulses being present then it would certainly be a very high
bandwidth recording device.

All of the above sounds like more work than putting the learning remote in a
box and posting it to the required location. Why are you interested in
this problem?

Chris
 
J

jasen

Jan 1, 1970
0
I don't own a web-cam but anyone know what would happen if
you replaced the IR LED with a diffused red LED and shone it close to a web
cam.

I don't think web cams record an analog video stream...
and if they did the compression would mangle it beyond recognition.
Starting with a normal IR R/C with its original crystal and normal pulsed
output of 25uS per pulse and 20 pulses per bit of data. Would that produce a
resolvable video stream that could be sent via internet and assuming a wide
enough acceptance spectrum of the receiving phototransistor/diode of a
learner type universal r/c straight off a pc monitor in a dark room.

webcam video uses a much lower frame rate than pc monitors use...
 
N

N Cook

Jan 1, 1970
0
Geoffrey S. Mendelson said:
I did that in the 1980's with an IR photodiode, an LM324 op amp and an
IR LED. Another thing I should of patented.

Geoff.

Thinking of worthy patentable devices
I wonder if anyone makes this sort of truly unirversal r/c for those
annoying situations of one or more key functions missing from the one you
want.

2 stages
1/ Just the recognition code going through all possible permutations
to find the basic power on/off repeated sequence.
Lock that down in memory
2/ and then after that specific code, all operational bit sequences until
that does a function on the TV etc and lock that to a button on the r/c.
 
G

Grumps

Jan 1, 1970
0
N said:
That is going across continents.
To transfer the pulse coding of a remote control at one site to
another learnable type remote control maybe the other side of the
world.
Can anyone think of a method that uses off the shelf equipment used
in a domestic environment , ie not using oscilloscopes etc.
Somehow slowing the pulse stream down enough to capture on
cam-corder/pc etc.
Would the average r/c with say a 400 KHz ceramic resonator still
function with the 400KHz one replaced with 100KHz one say.?

Maybe not a solution in your situation, but Logitech Harmony remotes might
suffice. You can 'teach' a device that you have in one location, and the
same device can be uploaded (via the interwebnet thingy) in another
location.
 
W

webpa

Jan 1, 1970
0
Grumps said:
Maybe not a solution in your situation, but Logitech Harmony remotes might
suffice. You can 'teach' a device that you have in one location, and the
same device can be uploaded (via the interwebnet thingy) in another
location.

Maybe I'm missing something important about the problem, but I use a
program called OmniRemote Pro....which is designed for Palm OS
hand-helds. Basically, it turns any Palm OS PDA with IR (all, as far as
I know) into a programmable, "learning," IR remote control. There are
many, many other software solutions that do the same thing for other
OSs (WinCE, Linux, Mac) and other hardware. There are also, on-line,
several databases of IR pulse codes for many consumer devices...from TV
receivers to air conditioners.
 
J

jasen

Jan 1, 1970
0
Thinking of worthy patentable devices
I wonder if anyone makes this sort of truly unirversal r/c for those
annoying situations of one or more key functions missing from the one you
want.

2 stages
1/ Just the recognition code going through all possible permutations
to find the basic power on/off repeated sequence.
Lock that down in memory

you would die waiting if it went through all possible codes.
2/ and then after that specific code, all operational bit sequences until
that does a function on the TV etc and lock that to a button on the r/c.

that bit is somewhat easier... once the baudrate, carrier frequency,
and encoding scheme are known all that remains is to experiment with
hundereds of possible symbols.

Bye.
Jasen
 
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