Reverse Engineering An LCD Display


The current marketplace allows hobbyists to easily find inexpensive, well-documented displays, but what if you wanted to interface with something more complicated, such as the screen on an iPod Nano 6? [Mike] has given us a detailed and insightful video showing his process for reverse engineering a device with little-to-no documentation. Here he covers the initial investigation, where one scours the web in search of any available information. In [Mike’s] example, the display uses an MIPI D-PHY interface, which he has never worked with. He learns that the MIPI Alliance will provide design specs in exchange for a signed NDA (Non-Disclosure Agreement) and a modest $8000 fee. Nice.

[Mike] shows off some serious hardware hackery, tackling some extremely difficult soldering in order to set up a proper test platform. He then demonstrates how to use a rather awesome oscilloscope to better understand the display protocol. We found it fascinating to see the video signals displayed as waveforms, especially when he shows how it is possible to count the individual binary values. The amount of information he uncovers with the oscilloscope is nothing short of amazing, proving these little devices are more complex than they seem.

[via Hacked Gadgets]

31 thoughts on “Reverse Engineering An LCD Display

    1. Yea, but then it’s still not legal to build anything with leaked docs. No, the better way is a clean room reverse engineer with extensive documentation. Then everyone can legally build upon it. I’m pretty sure protocols can’t be considered copyrighted other than as trade secrets. Unless you happen to step on the toes of a bunch of lobbyists when a magic number is leaked :)

      1. I’m with Earlz, you can also take it a step further, depending on the company, show them your reversed code and ask them if it’s ok to release, clearly if they’re making a bunch of cash off of their designs and selling licenses they’ll probably tell you to jog on and you still have the clean room option but with the right companies, they will talk to you.

        1. Searching for keywords, taking the results you did get, reading those looking for more keywords, getting good with google’s advanced search features, some lucky guesses… it’s not an exact science. Google’s translation service is also very helpful.

  1. In my world “LCD” stands for “Liquid Crystal Display”. So a LCD-Display, as it is named in the headline, is a display-display. I always wondered what a display-display would display, after it was done with displaying in the first place.
    Sadly even geeks don’t get that right any more these days. Sigh.

  2. ok then sign the agreement pay and get the documents then shortly later stage a break in (get a brick smash a window and then re arrange your pc to make it look like someone raided your pc)

    also maybe if you happen to do p2p you could set up a condition where it gets leaked stolen that way.

    another way reverse engineer then build the equiv using discreet parts like the 555 timer

    then post that build.

    if the display is not a loose part if it is part of a device then go out and buy the device and tear it down and reverse engineer it.

    not all of hackaday is legal i have seen some black hat hacks here or what was intended as neutral hats could be turned black or white by intent .

    for example the posting as proof of concept code for a zero day exploit.

    1. As much as I hate NDAs, you are saying that your word means nothing, and no one else’s word should mean anything either

      Mike’s word is his bond. I respect that greatly. It’s the standard I follow, and the standard I hope you will someday come to adopt and encourage yourself.

      The world has always had too many people who will say anything to get whatever they want in that moment. Today’s corpocracy (which assumes that corporations can/should be amoral) is just an extension of that. After centuries of law, executives and govts have only in recent decades begun to believe (incorrectly, under the law) that corporations are duty-bound [only] to maximize shareholder return by all defensible means. Now you’re advocating that we demean HUMAN morality to that level?

      Have fun in the world you’re creating.

    1. Who in their right mind would pay $8k for instructions to use a product you’re paying for? Would you sign a NDA and pay thousands for the instructions to assemble the furniture you bought from Ikea?

        1. What an utterly flaccid and completely disjointed analogy. It fails on all points an only points out quite a shallow mind behind it.
          You can’t possibly dislike Apple due to a non-existent NDA, an apple and oranges price comparison or equating a user ready OS to a technical implementation document. So it’s probably due to other, equally less rational and emotional opinions on your part.
          I chose OSX because it’s a decent *nix with a proper desktop experience. Something that Linux, Solaris and other *nixes have failed to do. Linux is fine for headless, as you well know.

      1. Companies producing a product based around the part these licenses are not intended for individuals.
        Interestingly the Chinese generally do not acknowledge stupid things like NDAs and will even clone the part so the specs to a similar Chinese part may be very similar.

  3. Seriously, leaking NDA stuff is not cool, really, it isn’t, people seem to want instant gratification without putting any effort in.

    The ikea argument doesn’t really stand up too well, at least in this instance, the devices are sold as replacement screens for a commercial product, they’re not sold as a hobbyist item, you don’t need an NDA document to plug one in.

  4. NDA is a signed contract. The other part can sue you for damages. So it
    is law suits+damages on top of $8K.

    While you could reverse engineer the protocol, you might put yourself in
    legal trouble. There could also be patent(s) that are being used in the
    protocol. Also you probably can’t mention MIPI D-PHY anywhere as they
    probably have it as a trade mark.

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