Tuesday, June 26, 2012

Raspberry Pi (modding Atrix Lapdock) - update 17 April 2013

I ordered a Motorola Atrix Lapdock to connect it to my Raspberry Pi. It's fairly cheap thinking about what you get (11.6" 1366x768 screen, USB hub, keyboard, touchpad, battery, charger and a case that hosts all of them).

So, the lapdock has a micro HDMI male connector (type D) and a micro USB male connector. The raspberry has a type A HDMI female connector and a female micro USB connector. I tought of adding a male type A HDMI connector to the lapdock so that I could connect the RPi directly to the lapdock.


The HDMI type D connector is real small (@6mm wide) and is composed of 19 little wires (actually 18, CEC is not used). Here are some pictures with the original (disassembled) connector from the lapdock:
As you can see in the pictures, pin 7 is a GND pin which means the pinout is not compatible with the type A HDMI connector. After searching (and searching) the web for a type D connector pinout, I came across the following one which seams OK. I think the problem is that type D is not an HDMI standard (yet).
So, the rest of the work is unsoldering wires from type D connector and soldering them to the type A connector. Of course the cable from the lapdock is very short so I had to add some wires to make the little cable longer so I could centrally fit the type A connector. Also the USB cable had to be made longer so it could fit the Pi just right.
After some holes, soldering and gluing into place some hours later, here are the results:

I will soon post about more mods for the Raspberry Pi.
Leave your comments and suggestions below.

Update 17 April 2013:
A lot of people ask if touchpad and keyboard work. Yes they work! But I forgot to mention that you have to get D+/D- wires from a big USB port to the micro USB port. You can notice in the pictures that the dual USB connector is removed (replaced it with a single USB connector) and the second USB has the data lines routed with wires to the micro USB connector.

33 comments:

  1. So, the lapdock's keyboard and touchpad work?

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  2. Thanks for your pictures. Now I have HDMI in. :)

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  3. If you still want to use your Atrix, Maybe easier to use a HDMI Male to Micro HDMI Female Converter. Focal price do them for $5.

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    Replies
    1. I bought the lapdock specially for the RPi.

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  4. Andrei, thank you so much for the guide and especially for the pin outs table!

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  5. Any thoughts on the power off blip when opening/closing the lid?
    Have you managed to solve it?

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    1. I added a Li-Ion battery on the Pi itself but the bad news is that the lapdock cuts out the voltage on the 2 USB ports. This means that if I have a USB device connected to the Pi, when I close the lid it will be reset.

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  6. Hello Andrei!

    I am attempting this same mod and I am running into some trouble.

    Instead of wiring to a connector I am wiring directly to a Type-A HDMI cable. When I plug in the HDMI cable the touch pad LED lights up and I can toggle it on/off. When I power on the PC the touchpad LED turns off and nothing displays. If I turn the PC off the lapdock says "no hdmi signal".

    Do you have any idea which wire might be causing the problem?

    Does every wire need to be connected? Such as 5v or SCL / SDA?

    Also my "shield" wires on my HDMI cable are all bundled together so I soldered them to all of the "shield" wires coming out of the lapdock. Is that correct? Do you know exactly what those are for? Every site I've found say that they protect the twisted pairs from interference. If that's true wouldn't they not be 100% necessary for a signal?

    Thanks for any help you can give me! Great work on your mod!

    -Adam

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    Replies
    1. Hi,

      Yes, all the wires need to be wired. SCL/SDA provides information from the monitor/TV about the supported resolutions. Without them, the monitor will not be correctly identified by the HDMI source.

      About, the shield wires: yes, they protect the signals from interference. They are 100% necessary for the signals (at least one of them). Since the signals are very high frequency, they can get really distorted without the shielding if the cable is relatively long.

      Good luck!

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  7. Hi,
    I tried doing the exact same thing you did, but buggered up a bit. I'd like to pick it up again and fix it!

    I kinda messed up the USB wiring and was wondering if you could provide me with a pinout for that as well, since the wiring colours are not standard and I can't seem to trace them to the motherboard.

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  8. Did you have a bare wire soldered to the outer metal of your Type D connector? Mine looks very different from the pictures above.

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    Replies
    1. Yes, it's the shielding. You can connect it to the bare metal of the type A connector.
      The picture above is the micro connector disassembled (after removing the metal piece). In this way, you can see better which wire goes where.

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  9. Hello Andrei !
    I have a stupid question i guess, but i am trying to use the lapdock for an Android HDMI Stick (MK808).
    I was successful of making the HDMI connection using an adapter from the webdock "micro HDMI" to a normal HDMI.
    Fine !

    But stupid enough i am not successful on he USB side which i thought to be easy.
    I bought a micro USB extension, cut it and that gave me access to 4 wires. I wired those to a Standard USB Connector and i am not able to use mouse / keyboard. Not on the ANdorid stick and not on a regular PC.
    Do you have any help ? Do you have a pinout ?

    Thank you for help...

    Nils

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    Replies
    1. Sorry, but I don't have the USB pinout for the lapdock and I don't think I'll open it again anytime soon.

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    2. I read your post more careful. I think you need to try a micro USB to USB female adapter (OTG cable) with your MK808. Let me know if it works because I was thinking of buying one of those.

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    3. Hello. I'm working on the same project. Connect mk808 to lapdock 100(razr version) so you need to use a micro USB connector. Not a normal USB port. (When you say mouse and keyboard) you're talking about lapdock keyboard and touchpad?

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  10. Hi, I have an atrix lapdock and I'm planning to get a more powerful board like the ODROID-U2 by HARDKERNEL. The U2 uses 5v 2a and I have 2 problems.
    First, the lapdock most certainly does not supply 2a from the micro usb connector(have no idea how much power it carries)
    Second, I'm trying to figure a way to integrate the board into the lapdock to make it aesthetically pleasing while functional and portable. The U2 is rather small(smaller than the raspberry pi) and I thought it would be easy to create a cavity to hide the U2 in the lapdock but the lapdock is really really really thin.
    Any ideas?

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    1. Nice board.
      Didn't measure it but I think it supplies at least 1A (otherwise it would take ages to charge the phone from it).
      I don't think that board needs very much power, only when you connect USB devices - which you can connect directly to the lapdock.
      Not sure how you could fit that nicely. I was thinking also, at some point, to integrate the Pi in the lapdock.
      I think I will get a MK809II to use with the lapdock.

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  11. A question. I have the Lapdock for the Atrix - English/Hebrew keyboard. Part # ASMMB860LAPD.

    I don't have my couplers yet, so I don't know if they'll provide ground, etc. properly. However, I have a short time to return the unit if defective, and don't know if I'll get the couplers in time to test. So - is there some way to determine if the unit is functional without actually getting an HDMI connector connected to the Lapdock? This was a new, sealed, unit, so fairly certain it works - but would like to make sure.

    I see no power button, etc., so assuming it's got to be connected to power on. Battery charges, and there's the "battery test" button, which also seems to work - but that's it right now. Any other way to test unit?

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    Replies
    1. You would have to get a hdmi signal to the male micro hdmi connector. Without a way of doing that there is no other simple way to test it.

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  12. how did u extend the micro usb? and also how do u make it so that you can transfer data through micro usb?

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  13. can you show me how you extend the micro usb and how to make the micro usb from the raspberry pi to transfer data?

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    1. As you can see in this image:
      http://3.bp.blogspot.com/-IlKQDATIwGI/T93IhY4Q8bI/AAAAAAAAAao/etqtwJzZfak/s1600/P1080247.JPG
      The micro usb has just the two wires (D+/D-) extended from one of the big USB connectors. It's still USB host, not USB device so that it can handle the internal lapdock USB devices.

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    2. for the lapdock i've found that it has 7 wires, yellow, a orange, a red, a fainted orange or red a silver shiny line and 2 black lines which lines are which? i wanna also add a usb into it because raspberry pi version b does not have it like you do

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  14. I have 7 lines when extending which wire is which?

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    Replies
    1. I'm sorry, but I can't remember. You need to probe them. As I recall, 5 of them are used for power (2 - 5V and 3 - GND) and the other 2 are D+/D-.
      Good luck!

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  15. I'm looking in to getting the axtrix 4g laptop dock english/hebrew like tim underwood has. Will this work with the pi? I'm not going to go all in like yourself. I'm planning on using adapters to go from micro to normal hdmi.

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  16. Will the english/hebrew version work for this project?

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  17. hi,

    is there anyone so kind and show me the hdmi pinout? last year one pin of the micro hdmi was broken, so i unsoldered the hdmi cable of the ld and now i cant remember which cable is connected with which pin. so i need the pin of the root and the pin no of the micro usb.

    thanks in advance
    regards

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