Introduction: The Raspberry Pi - Lapdock Connection

Picture of The Raspberry Pi - Lapdock Connection

Now that you have your nifty new Raspberry Pi, you'll need a display for
it. Teensy analog monitors are pretty cheap, but what you really want is a
decent HDMI display. Unfortunately, they're expensive, running from
$150 on up into the thousands for the huge ones. But, for about $75
(or even as low as $40, used, on eBay) you can get a discontinued
model of the notorious Motorola Atrix Lapdock, the one that sold for
$500 a couple of years back, and it was a bargain at that price. The
lapdock incorporates a razor-sharp 11" HDMI display, an almost-adequate
keyboard-with-trackpad, twin speakers, and a high-capacity battery --
all in a thin two-pound package.

The Atrix Lapdock was manufactured to mechanically connect with the
now-discontinued Motorola Atrix smartphone, in effect turning it into a
laptop computer. The lapdock has two plugs on a foldout hinge -- a male
micro-HDMI plug and a male micro-USB-A plug. These neatly mate with
an Atrix phone, slipping right into appropriately positioned jacks on the side of the phone.
Fortunately for us, the lapdock's USB and HDMI ports are electrically
standard, even if the physical connectors aren't. If we could just find the
correct cables and adapters, we might be able to hook up our Raspberry Pi.
Maybe. Hopefully. . . .

Yes, it can indeed be done!

for example.

In this Instructable I will break down the process in detail, with
appropriate explanation and close-up pictures.

Step 1: Parts Required

Picture of Parts Required
We need cables and/or adapters to hook up from:
  • The Raspberry Pi's standard HDMI jack
  • to the lapdock's micro-male HDMI plug.
  • One of the Raspberry Pi's standard USB jacks
  • to the lapdock's micro-male USB plug.


 HDMI Micro Female/Female Adapter
(Such as this, for example.)

HDMI cable, micro-male to (full-size) male
(for example,
6ft Micro HDMI to HDMI Male M/M Cable for Droid Razr Atrix 2)

or, substitute for the above adapter and cable,
an HDMI micro-female to (full-size) male dongle.


USB micro-female to (full-size) female cable
(Such as this one, for example.)

USB A-male to A-male adapter (each end full-size)
(Such as this one, for example.)

Total cost for adapters and cables:
somewhere in the range of $10 - $20,
and closer to $10 if you're a shrewd and lucky shopper.

Getting your hands on the cables and/or adapters is the hard part.
After that, it's just a matter of actually making the connections.

Step 2: Hooking Up

Picture of Hooking Up

Open up the the narrow panel on the back of the lapdock and take a good
look at the two jacks protruding from it.

The micro-HDMI adapter (or the dongle, if you're using that instead) slips
over the end of the micro-HDMI jack on the lapdock. The micro-female end
of the USB cable slips over the end of the micro-USB jack on the lapdock.
Note that it may be necessary to shave a bit off the micro-female end
of the USB cable if it doesn't go down far enough over the male jack on
the lapdock (refer to pictures).

Now, we'll hook up to the Raspberry Pi.

The USB cable connects to one of the USB jacks on the Raspberry Pi.
Since the cable terminates in a female jack, we'll need either an A-male
to A-male USB adapter or an A-male to A-male USB cable. The A-male
end plugs into one of the Pi's full-size USB jacks.

Our HDMI cable has a micro-male plug on one end, and this goes into the
micro-female HDMI adapter on the lapdock. The full-size male end of the
cable plugs into the HDMI jack on the Raspberry Pi.

Finally, there's the issue of powering the Raspberry Pi.
The latest revision of the Model B, rev. 2.0, omits the fuses on the
USB bus, so the Pi can be powered from one or the other of the USB ports.
This mean that the Pi can get its power from the lapdock, through the
same USB cable previously discussed. Owners of earlier model Pis have a
couple of options for power. The simplest is to just plug a power cable
into the micro-USB power port on the Pi, as usual.

Step 3: An Alternative HDMI Adapter

Picture of An Alternative HDMI Adapter

Rather than a set of micro HDMI adapter cables, as shown in the previous step,
you can substitute a micro-female to male HDMI dongle. This has the advantage
of holding in place the Pi at the back of the lapdock.

You will need to whittle down the dongle on its side and back,
so it will fit all the way down onto the lapdock HDMI male plug,
and to allow room for the USB cable to fit alongside. See pics.

Caution: Take care when plugging or unplugging the dongle.
There's quite a bit of leverage there, and a wrong move could
conceivably break off the lapdock's micro-HDMI connector.

Update: Yet another alternative is the newly available HDMI micro-female-to-standard-male cable

(see last pic). These critters are rather pricey, about $7 each, including shipping.

Step 4: Another Way to Hook UP

Picture of Another Way to Hook UP
Would it work if we connect the Pi only to the HDMI connector on the Lapdock?
This would use the Lapdock only as a display, with the keyboard and trackpad
disabled. Yes, it works!

  1. More flexibility in the setup.
  2. You can use a better keyboard and an optical mouse that is more responsive than the trackpad on the Lapdock.
  3. Since the Pi is not powered from the Lapdock, there is no issue with power off when the Lapdock lid is closed.

  1. There's a mess of cables spread out all over the place, and the setup is much less portable.
  2. You need to add a powered USB hub.
  3. You need to connect a power supply to the Pi power jack.
  4. The two USB jacks on the Lapdock are no longer available.
  5. Not all keyboards work with this setup.

Step 5: Powering Up

Picture of Powering Up

Power up the lapdock by plugging in its supplied AC adapter. If the
battery has been charged, then this is optional.

Open the lid of the lapdock. The display will be dark, since there is
no signal coming in yet. Now, hook up the USB cable, with appropriate
adapter if necessary, as previously discussed. The Pi will not yet power
up from the lapdock because . . . the lapdock needs to sense a signal
source attached to its HDMI jack in order to supply power through its
USB bus
. So, we will at this point attach the micro-female-to-micro-female
HDMI adapter (with micro-male end of the HDMI cable inserted) to the
lapdock's micro-male HDMI jack. At this point, you may get a no-signal
message on the lapdock screen. Now . . .

Let's carefully plug the full-sized male end of the HDMI cable into the Pi's HDMI jack.
What's happening? The power and activity LEDs on the Pi board have lit up.
And, look! We're getting the bootup messages scrolling on the screen.
We're up and running.

Note that on your first boot you may have to type startx on the console
command line. After that, you'll be able to set an automatic boot
to X Windows.

Step 6: The Wi-Fi Connection

Picture of The Wi-Fi Connection

We can always use an ethernet cable to connect the Pi to a router to get
on-line, but wireless is so much more convenient. Many of the mini wifi
dongles work out of the box, though you may need to get drivers or do some

The Tenda W311MI Pico Adapter and the Edimax EW-7811 work with the Pi.
They cost about $10 apiece. (There's a fairly complete list of working hardware for the
Pi on the eLinux page.)

You can plug the wifi dongle into a USB jack on the back of the lapdock,
near where the power cable plugs in. The first time you boot up with the
dongle in place the Pi may not recognize it or you may have to configure
it by clicking on the Wifi icon. After that, you'll get on-line automatically,
if you've done everything correctly (and the moon phase is right ...).

Step 7: Tips and Troubleshooting

Picture of Tips and Troubleshooting
What if you don't get a display on the lapdock or if the display is
intermittent or flaky?

The HDMI cable may be bad. This is especially true of cheap cables,
where the metal shell is improperly grounded. Try a different HDMI cable.

Closing the lid on the lapdock causes the Pi to turn off and/or reboot.

This is normal behavior for the lapdock. It was designed as a power-saving
feature. Hooking up an external power supply to the micro-USB power
connector on the Pi fixes this.

Using the lapdock's trackpad and mouse buttons is so darned frustrating.
If the cursor freezes, then this means the trackpad has turned off.
Turn it back on by tapping in the upper left-hand corner of the trackpad,
so the light comes back on. Or, you can always get a cheap optical USB
mouse and hook it up to a USB slot on the Pi.

Highly recommended is hooking up a powered USB hub to one of the Pi's
on-board USB slots.

The standard Linux distro for the Pi is Raspbian, but try some of the other ones
as well.

The Motorola Droid Bionic lapdock works just about as well as the original Atrix lapdock.
The HDMI and USB plugs in the back of the Droid lapdock are rotated 180 degrees from the
ones on Atrix lapdock, but that makes no difference when hooking up a Raspberry Pi.
On balance, though, it's quite usable, especially considering that this baby is available (used)
on eBay for $35 - $40, with shipping included. See,
for example. Note that because the HDMI plug on this model is at a different angle from the Atrix
lapdock, an micro-HDMI cable with protruding metal jack gives the best connection (see picture).

Finally, here are some links to other people's experiences with hooking
up an Atrix lapdock to the Raspberry Pi.

Parker Reed's video on youtube:


DoctorEvil30564 (author)2014-01-09

will any of the other motorola lapdocks for other phones work with a raspberry pi? I'm looking at Droid Bionic and Droid RAZR Lapdocks on ebay, they appear to be much cheaper than the available atrix lapdocks.

frakman1 (author)DoctorEvil305642017-02-26

Yes, the Droid Bionic lapdock should work too. I've seen it here on youtube:

JackF48 (author)2016-02-28

I made a Windows 10 version of this. I call it the Litetop. The phone is the PC and broadcasts wirelessly to the Atrix.

You can see it working here:

DavidB871 (author)JackF482016-07-11

Hey, I noticed your video shows that the mouse trackpad works. But what about keyboard? I am trying ensure that the micro usb at the back of the Lapdock was not required in anyway for Input.

And would it be mircast or widi you connected from your phone?

JackF48 (author)DavidB8712016-07-11

I think it was a bluetooth trackpad and keyboard to my phone. So I think the keys probably worked as well.

I plugged this in in the back:

I would imagine you could use any Miracast adapter but you'd need to check.

JackP60 (author)JackF482016-04-15

hey would you mind posting a video or comment on how you got it to connect wirelessly to your phone? i would like to try and connect a lapdock to a nexus 5x but it would be nice to not have a bunch of cables.

JackF48 (author)JackP602016-04-17

I plugged this in in the back:

I would imagine you could use any Miracast adapter for a nexus 5 but you'd need to check. I had to take off a bit of the mounting on the back of the lapdock to be able to fit it on. I was able to kind of click it off and click it back on though.

RohanP1 made it! (author)2015-04-21

It was very simple!

JoeC47 (author)RohanP12015-09-27

Nice, Where can I find this white cable taht your using ? is it a micro usb femal to double micro usb ? Thank you

Uday_Vyas (author)JoeC472015-11-08

I researched and found the following - Micro usb male to female 1 to 2 Y Splitter cable V8 Phone sync data charge Cord .. i hate it when someone doesn't respond to other peoples request in timely manner .. :).. hope it helps u satyac and Joec47

DerekD29 (author)Uday_Vyas2016-01-24

I would be careful using this cable without modification. You will want to cut the power wire in the data cable. This will prevent an issue with both devices trying to provide power down the same cable. I am looking to find a similar cable, but one that does not provide power to one of the ports so I don't have to hack up a cable.

postitman (author)Uday_Vyas2015-11-10

Here I found it for the rest of the world as the above is not Shipping to Germany for example

JoeC47 (author)Uday_Vyas2015-11-09

Thank you so much Uday_Vyas ! I searched it for weeks now !

satyac (author)RohanP12015-10-06

Rohan may i know where you got both white and black cables form.Your design looks good without hectic cables around.

greenonline (author)2015-07-14

Never both... really? Where did you learn that?

mohammed.wilders.5 made it! (author)2015-02-22

I have just made one. I am using the Raspberry pi 2. I could still use the raspberry pi 2 with the usb cable of the lapdock, without performance issues yet. But that could be because I didn't do any intensive tasks (yet).

I'd like to upgrade to the Pi 2 aswell, but the power consumption is a concern for me aswell.

Have you found any problem since your oiginal post?

I have installed retropie on it which is using a lot of CPU/GPU power and also overclocked it to its maximum, but didn't find any problems yet.

Recently bought a Pi 2, but haven't had a chance to use it yet.

Getting mine in the mail tomorrow. Gonna report here if there are significant power issues.

MoTinkerGNome made it! (author)2014-12-31

I did it. One thing to note with the B+ is that you kind of have to jump start it using a 5v signal. on the power jack before it can backfeed the Pi. Once the pi is running you can remove power as long as the main USB connection is made.

I am not all that concerned with the remote possibility of the Pi getting damaged via 5v through the USB bus. If i let the smoke out then woops I wont do that again...

thegrendel (author)MoTinkerGNome2015-01-01

Thanks for the info on the B+. Watch that smoke business, though.

prtsn (author)2014-11-30


I have problem with the lapdock, I am using alternative hdmi adapter and micro usb female to usb male adapter to power up. When i power up using rasp pi or rikomagic or normal pc (using extra usb otg ) i get blank screen with little white background for 10 secs and powers off. But still the keyboard will be working for some time. I have tried many ways of connecting with multiple adapters but still i am facing this issue, could you please help me on this? Also the lapdock 100 connectors I am using is wire based and not rotation based ones.

thegrendel (author)prtsn2014-11-30

Some HDMI adapters are incompatible and will not work with the lapdock. I've run into this myself.

prtsn (author)thegrendel2014-12-04

Thank you very much for your reply!!

You think the problem might be only because of HDMI adapters and not with the Lapdock itself? If so is there any way to test if Lapdock is working fine without the use of HDMI adapters?

davidbarcomb (author)2014-11-25

Very nice. Thank you for the instructable

thegrendel (author)davidbarcomb2014-11-25

You are very welcome. I hope it was helpful/inspiring to you.

cm1556 (author)2014-10-30

Hi! Hope you won't mind helping a non-techie. I have the Lapdock 100 and a Razr Maxx. The phone is dying so I'm wondering how I can use the lapdock with other phones, because the conversion to work with RPi is a little beyond me. First, what do each of the HDMI and USB do in transferring the phone functions to the lapdock? And how could I connect another phone to the lapdock to get the same functionality?

thegrendel (author)cm15562014-10-30

I have no experience with cell phone hardware, so regrettably I can't be of any help to you on this.

Crafterkid123 (author)2014-09-25

how would i be able to hide the raspberry pi inside the laptop? also, does it power itself AND the pi? just wondering.

thegrendel (author)Crafterkid1232014-09-26

1) Can't hide it inside the Lapdock, as far as I can figure. Not enough room.

2) The Pi needs 500+ ma, and therefore its own power supply,
otherwise it will not operate reliably.

tony.steinbock (author)2014-08-17

Thank you for this article. I like this project!

thegrendel (author)2014-04-04

Sorry, but I'm not in a position to do this.
And, I'm not in Toronto.

dnicol1 (author)2014-04-04

Hey i am also in Toronto. Very cool projects you have. Would you be i nterested In a paid project? Need something done right away.

yvandercoilden (author)2014-02-05

I just tried to build this combination of RasPi and Lapdock. Well, the RasPi boots, so it is getting enough power through usb. I do also see everything on the display.

But the keyboard and also the touchpad do not work. What may be the problem?

Check the USB adapter/cable.

Shantorian3d (author)2013-11-17

Just got mine working ^_^

thegrendel (author)Shantorian3d2013-11-17

I'm glad I could be of help.
Good luck!

nerd7473 (author)2013-11-06

does anyone know the answer to this?

nerd7473 (author)2013-07-20

very cool you should make it to where the pi is protected so you can carry it around

sonicdude10 (author)2013-07-01

I'll be doing something like this but with one of those Android smart TV sticks instead. I've learned that some of the common sticks like the Rikomagic models will fit in place of the phone dock connector once the plastic is removed from inside the flap. this allows for better stability and the flap can stay closed for a more streamlined look. I may run Linux once I get it going.

I may make an Instructable for doing this. After all, those sticks are now quite powerful and still affordable. For $90 I can get a brand new model that has Wifi, Bluetooth, micro SD slot, 1.8GHz 4 core Cortex A9 CPU, 4 core Mali GPU at 533MHz, 2GB DDR3 RAM, Android 4.2.2, and other stuff. Should be quite speedy.

Some holes drilled in the docking flap where the PC guts lie to aid in cooling and I have a cheap Android laptop for my stuff.

thegrendel (author)sonicdude102013-07-01

Excellent. If I can inspire people such as yourself to do similar,
or better things than I did, then I consider my Instructable to
be a success. And, I strongly encourage you to document your project with an Instructable.

mringman (author)2013-05-23

Wasn't that. Finally just plugged a mini USB cable into a USB wall outlet and that made it work

mringman (author)2013-05-23

I am having trouble with getting the keyboard and trackpad to work. Suggestions for things to try?

thegrendel (author)mringman2013-05-23

Try a different USB adapter/cable.

See if the little light in the upper left hand corner of the trackpad
is on. If not, try tapping it to switch on trackpad and keyboard.

old_alex (author)2013-03-28

I have done this, as many have and it is very particular about the HDMI cable, you may want to boost the HDMI current in the config file if you have an issue with no video.

If you have a keyboard race condition it is most likely a power issue. Given the will use about 700 to 1000ma, your cable should be short with a high current. You can by a Y cable (blackberrry) to put power into two ports (more current mico usb and standard).

The HDMI to micro HDMI anc be finicky seat it properly. Power to the USB only happens if a "good" connection is detected. One hacker opened up the box and exposed the HDMI connector soldering his own cable.

The origional (not me) post was on Raspberry Pi Forum:

thegrendel (author)old_alex2013-03-29

"The HDMI to micro HDMI anc be finicky seat it properly. Power to the USB only happens if a "good" connection is detected. One hacker opened up the box and exposed the HDMI connector soldering his own cable. "

A valid point. The HDMI connection is absolutely critical.

kokid99 (author)2013-03-28

This isnt really an original design, Adafruit had done this design first........ Originality please?

thegrendel (author)kokid992013-03-28

I'm not claiming originality, whatever that means.
And in the last step of this Instructable I have a partial list of URLs
of others who have done this project before me. I will note, though,
that I haven't been able to find another Instructable dealing with
this particular project.

And Adafruit was not the first to do it, either.
The Adafruit method of hooking up involves soldering,
and in any case, the methodology is confined to a youtube video.
I've done it in more detail, and with close-up pics.

Kid, there's nothing at all wrong with multiple persons submitting
the same or a similar project. It give you alternate ways of doing it
and alternate points of view on technique.

About This Instructable



Bio: hobbyist, tinkerer, old curmudgeon
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