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jask
Joined: 17 Mar 2006 Posts: 10165 Location: kamloops BC
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Link Posted: Thu Dec 06, 2018 5:04 pm Post subject: Reverse engineering an IR contol? |
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I was wondering if anyone here has any ideas or suggestions or experience with tying to find the codes for an IR system that is missing its remote control? This is probably more trouble than it is worth but I have a set of Chinese made speakers that are missing the remote that allows source selection ,mute,volume,etc. I have searched all of the remote databases online but the speakers are an OEM that builds for various distributors. This is an unsupported "legacy" product and the distributor had no info on the IR codes. I was wondering if there is any sort of automated brute force software, or if anyone who has done integration has suggestions on how to determine what the IR codes might be so that another remote or phone could be used to replace the lost remote control.
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Link Posted: Thu Dec 06, 2018 8:31 pm Post subject: |
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Was going to recommend an IR database like this one: https://www.commandfusion.com/irdatabase
But you've already gone that route.
What about manual brute force? What do you have now that you want to use to control them? Some Logitech or Harmony universal remote? They must come come with a list of hundred or so post popular manufacturer names with codes to try (even my old Bell satellite receiver remotes have a few pages in the back of various manufacturers and the codesets to try).
My guess is that there's lots of overlap on codes so if you start going through them trying one by one you may eventually you'll hit on one that works, at least for the most basic functions (on/off/volume).
Kal
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kal Forum Administrator
Joined: 06 Mar 2006 Posts: 17860 Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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barclay66
Joined: 27 Jun 2011 Posts: 1291 Location: Germany
TV/Projector: Marquee 9500 Ultra
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Link Posted: Thu Dec 06, 2018 8:54 pm Post subject: |
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Hi,
First of all, IR isn’t all the same. The receiver will be optimized for a specific wavelength so You might need to test using different IR emitter diodes.
Second, the codes usually are transmitted through a modulated carrier. So, different carrier frequencies need to be tested.
And, last but not least, the coding scheme (e.g. start code, command and end code) plus the relevant command code itself need to be identified.
Not an easy task to do.
If I had to do this, I would get an Arduino, a set of different IR diodes plus some additional parts (e.g. switching transistor and resistors). With this, I would build a programmable remote transmitter. There should be lots of examples and libraries available on the web. Starting with typical examples, I would start varying the parameters until getting a reaction on the device. Using clever programming, several sequences could be run automatically and the power light of the device could be “read” using a light sensor connected to the Arduino. So, the sequence could be interrupted and on a display the valid carrier/sequence/code could be shown.
If You want to know more about IR concepts, do a research on “RC5”. This is a very common system...
Kind Regards,
barclay66
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Clarence
Joined: 08 Mar 2006 Posts: 3793 Location: Smith Mtn Lake, VA
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Fri Dec 07, 2018 1:04 am Post subject: |
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Multi remote, do a code search and when/if you hit on the codes you can copy them off the multi.
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jask
Joined: 17 Mar 2006 Posts: 10165 Location: kamloops BC
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Link Posted: Sat Dec 08, 2018 7:03 am Post subject: |
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thanks all! Jeremy- what do you mean by multi remote? Kal I do have a few harmony remotes but the ideal would be to use one of the boys Android phones that have IR blasters...since the speakers will probably end up with one of them if we can establish control. I will dive into your ideas on the weekend Clarence and Barkley-- thanks !
i found a schematic based on the OEMs FCC submission (yeah!! bluetooth) and at a quick glance the 1738 IR and chips, looks likely to be NEC vs Phillips but who knows... another online friend found a Harmony code set for a previous model that had way less options but might give me a starting point for testing...
thanks again.
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AnalogRocks Forum Moderator
Joined: 08 Mar 2006 Posts: 26690 Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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Link Posted: Sat Dec 08, 2018 7:27 am Post subject: |
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jask wrote: | thanks all! Jeremy- what do you mean by multi remote?
thanks again. |
Universal remote that can control many devices. Most have a code search feature that allows the rremote to cycle through all the codes in the remote to find sometging that works
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CRT.
HD done right!
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