'Long distance' IR remote control learning.

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.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM
IL Voice: (07)-7424-1667  Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
Visit my 'blog at http://geoffstechno.livejournal.com/

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.

--

Bye.
   Jasen

to

function

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.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

[----8 > > To transfer the pulse coding of a remote control at one site to another

Webcams can usually see near-IR reasonably well anayway.

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

Tim

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.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com  N3OWJ/4X1GM
IL Voice: (07)-7424-1667  Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
Visit my 'blog at http://geoffstechno.livejournal.com/

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

I don't think web cams record an analog video stream... and if they did the compression would mangle it beyond recognition.

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

--

Bye.
   Jasen

pulsed

produce a

wide

1-215-821-1838

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.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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.

you would die waiting if it went through all possible codes.

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