Over at the Raspberry Pi forums, a lot of people have come up with a lot of great ideas for connecting the Pi to a Motorola Lapdock. There are so many ways to do this, in fact, that I found it really difficult to figure out which one I should go with. I couldn’t even keep all the parts straight in my head, so I made a diagram:
EDIT 9/28/2012: If your Pi is model B revision 1.0 + ECN0001 or revision 2.0, then you don’t need connections 3, 4 or 5. Also, you don’t have to cut the 5v wire in connection 2. This makes things a lot simpler, so it is a good idea to get one of these later boards if you can. See this post for the instructions to find out which revision you have. See this article for the pics.
It’s a little bit confusing so I’ll explain what the various lines mean:
- The letter M (for male) denotes a connector on the Pi or Lapdock, whereas the letter F (for female) denotes a port.
- The Pi (upper) has three ports that must be connected: a HDMI port for the display, a USB port for the keyboard/trackpad input, and a micro USB port for power.
- The Lapdock (lower) must connect to the Pi’s display port via a micro HDMI connector. This is connection 1 in the diagram.
- The Lapdock must also connect to the Pi’s keyboard/trackpad port via a micro USB connector. This is connection 2.
- The Lapdock can connect to the Pi’s power port via either of its two USB ports, or via its micro USB connector using a Y-adapter. These are connections 4 and 3, respectively. Alternatively, the Lapdock doesn’t have to connect directly to the Pi’s power port at all. Instead, we can power the Pi externally. This is connection 5. These connections are indicated by dotted lines because only one of them must be present.
Once I had a diagram, I set out looking for the parts. What I really wanted was a solution that required the least amount of money, clutter, and effort. Unfortunately, nobody seems to make a micro HDMI female to HDMI male adapter cable or a micro USB female to USB male adapter cable, so every option requires multiple parts from multiple sellers. Hopefully, this guide will make finding the right parts a little easier for you than it was for me.
Note: Some of the parts described below have multiple names. For instance, a coupler is sometimes referred to as a gender changer or a female to female adapter. An extension cable is sometimes referred to as a female to male adapter cable or a port saver (for HDMI). Keep this in mind if you can’t find what you’re searching for.
Disclaimer: I can’t vouch for any of these websites. You should always be careful who you give your information to online. Also, many of these stores are scattered all over the globe. Expect long shipping waits from those that are overseas.
Connection 1: Display
Option 1: Micro HDMI coupler + micro HDMI male to HDMI male adapter cable
You can find this cable at LINDY UK. If cost isn’t a concern you can find it on their US site as well.
This cable is not that hard to find. It’s the coupler that is so elusive. I was only able to find it on eBay from this seller in China.
Option 2: Micro HDMI extension cable + micro HDMI female to HDMI male adapter
I found this cable at All4Cellular in the US. You can also find it on eBay from this seller and this seller, both of which are also in the US.
You can find the adapter at Meritline.com, Focalprice or DX, all of which ship from China. LINDY UK also carries this, as well as LINDY US at a higher price.
Option 3: Micro HDMI female to HDMI male adapter + HDMI extension cable
See option 3 for the adapter. You can find the cable at any electronics store.
Option 4: Micro HDMI female to HDMI male adapter + HDMI port saver
Instead of using a cable, you can use a port saver such as this to connect the display. These things are a dime a dozen.
Option 5: Micro HDMI female to HDMI male adapter only
You don’t have to use a cable or a port saver with this adapter. You can just “mount” the Pi on the Lapdock’s micro HDMI connector, like this. See option 3 for the link.
Connection 2: Keyboard/trackpad
EDIT 9/28/2012: In case you’re just skimming, see my edit at the top of this article before you read this section.
Every option for making this connection require some kind of cable. This is because you must be able to cut the 5v wire so that power is not being sent to the Pi’s USB port.
Option 1: Micro USB extension cable + micro USB female to USB male adapter
I found this cable at DX in China and at All4Cellular in the US. The latter only sells it bundled with a micro HDMI extension cable, which you might want anyways. It’s also available on eBay from this seller in China, or from this seller in the US.
The adapter, which you’ll see used again and again in the other solutions below, is extremely rare. You can find it at Focalprice or on eBay from this seller and this seller. In any case, it’s shipped from China.
Option 2: Micro USB female to USB male adapter + USB extension cable
This is the second instance where this adapter would come in handy. See option 2 for the link. The cable is very common.
Option 3: Micro USB female to USB female adapter cable + USB male to USB male cable (Standard)
I found this adapter on eBay from this seller in China. There’s also a cable adapter from the same seller right here, and another type of adapter from this seller, also in China. The other cable is standard.
Connection 4/5: Power
EDIT 9/28/2012: In case you’re just skimming, see my edit at the top of this article before you read this section.
You can use a standard phone charging cable (micro USB male to USB male adapter cable) to connect either of the Lapdock’s standard USB ports to the Pi’s micro USB port. This is connection 4 in the diagram. You can find the cable at just about any retail store.
Alternatively, you can plug your standard phone charging cable into any other power source, such as a powered USB hub or an electrical outlet with a 5v 2000mA USB detachable charger. This is connection 5 in the diagram. The charger usually comes bundled with the cable.
Connection 2+3: Keyboard/trackpad/power Y-adapter
EDIT 9/28/2012: In case you’re just skimming, see my edit at the top of this article before you read this section.
If you’d like to have one less cable attached to your Pi, you can use a Y-adapter to connect the Lapdock’s micro USB connector to both the Pi’s standard USB port and the Pi’s micro USB port.
You have a few options that involve splicing and a few that don’t. Here are a couple that don’t:
Option 1: Micro USB female to dual micro USB male Y-adapter + micro USB female to USB male adapter
You can find this Y-adapter at DX in China, or on eBay from this seller in the US. See above for the other adapter.
Option 2: USB male to dual micro USB male Y-adapter + micro USB female to USB female adapter + micro USB female to USB male adapter
I found this Y-adapter at Opentip.com in the US. See above for the links to the other adapters.
For the adventurous
If you don’t mind splicing (or even possibly soldering), you can find a multitude of ways to accomplish this at this thread in the Raspberry Pi forums. Some of them are really cool, like this one by user selectnone and this one by kimondouk.
Let me know if you find another “easy” solution and we’ll add it to the list!
DaveDen 
Look at this one too: http://www.lindy.co.uk/0-5m-high-speed-hdmi-to-micro-hdmi-cable-with-ethernet/41350.html
Nice find! Added it to the list. Why are these things so much more expensive in the US? Is it because we’re further from China??
I am using :
Connection 2+3: Keyboard/track pad/power Y-adapter
Option 1: Micro USB female to dual micro USB male Y-adapter + micro USB female to USB male adapter.
Working like a champ when the connector doesn’t wiggle. Any ideas to modify this to insure a more stable connection?
Which connector wiggles? Is it the end that connects to the Lapdock’s micro USB, or one of the ends connected to the Pi?
If it’s the end that connects to the Lapdock, you should be able to remove part of the hinged thingy – the “dock” part of the Lapdock, or whatever. There’s this plate on it that is connected by a couple of magnets on either side. It pops off pretty easily. See if that helps.
I don’t recommend this, but I actually removed that whole component (the hinged thingy) because I didn’t like how close together those connectors were on the Lapdock.
The LapDock connections wiggle. I have removed the thing that you are talking about (it removes to allow the phone to be attached while in a case). I think I’ll try to cut a piece of plastic as a backing and glue them together … that may make it more secure. Not a show stopper, just an irritant.
Great post, this saved me a lot of time scrounging for the bits. Thanks!
Hi Dave, thanks for your great page.
I`m not sure, but under “Connection 1: Display – Option 2:” the link to LINDY UK shows me a cable that might not be the right one. It seems to be a Micro HDMI (male) to HDMI (male) cable but I think we need a Micro HDMI (female !!!) to HDMI (male) cable.
Best regards
Thomas from Germany
Oops. That one should be under option 1. Thanks!
Hi Dave,
Just a bit confused about the need to cut the 5v wire. Does that apply as well to Y-adapter from the ‘Connection 2+3’ section as well?
cheers,
Chris
Chris,
Yes. If your Pi version is less than model B revision 1.0 + ECN0001, then you need to cut the 5v wire inside the USB cable that would plug into the Pi’s standard (not micro) USB port.
I have a Lapdock and Atrix 4g upgrade kit (micro HDMI M to F and micro USB M to F) however when I connect my Model B revision 1, the RPi will boot but NOT accept commands from the keyboard or trackpad. I think I need a USB Male to Male (Type A) cable to go from the Lapdock USB port to the RPI USB port. Right?
The Pi will only receive keyboard/trackpad input on the standard USB port. The micro USB port on the board is for power only.
that is what I thought. I need a USB Type A to Type A cable with the red wire cut so as to not supply power to the USB port
I got a USB Male Male cable and cut the Red wire to avoid blowing the fuses on my early model RPI. Plugged it from Lapdock USB female to RPI female port, but keyboard and trackpad still don’t respond. I think the mini USB port has to be connected to the RPI Female USB port. I will try to get a micro female to full size female adapter
The Lapdock sends keyboard/trackpad input using its micro USB male port. This is connection 2 above. You can use the Lapdock’s standard USB female ports for additional peripherals, like a USB drive or wifi adapter, but I think that’s about all it’s good for.
I got a micro female USB to Male Type A usb adapter and plugged it into my micro female micro male USB cable and plugged the adapter into the RPi USB port.(connection #2) I shorted out the F1 F2 fuses with an alligator clip but still the keyboard/trackpad are not recognized. They are when I use a separate USB keyboard plugged into the same USB port. I also have the micro HDMI cable connected to a micro HDMI to regular male HDMI adaptor which allows the monitor on the laptop to work. (connection #1)
I’m not sure why it’s not working then. Could be a bad cable. Do you have a standard type A USB extension cable? Those are fairly easy to find. I use one like this:
Lapdock micro USB (M) -> micro USB (F) to type A USB (M) adapter -> type A USB (F) to type A USB (M) cable -> Pi type A USB (F)
I have noted a couple of error messages during boot up. usb1-1.2.3 can’t config#1 error -110 and hub 1-1:1.0 cant reset port 3 error -110 using different OS’s. I don’t have an USB extension cable USB Female to USB Male, but will try to find one. The USB micro female to micro male was from All4Cellular like the HDMI micro female to micro male cable.
I found this. I will buy one and report how it works.
http://www.miniinthebox.com/hdmi-female-to-micro-female-adapter_p472020.html
Very nicely done.
One thing to consider is that you probably want as little as possible on the Lapdock’s connectors in terms of mass. So even though it’s a bit more expensive, it’s probably better to use Option 2 for HDMI and Option 1 for USB.
Also for USB it wouldn’t be hard to splice cable together using the female half of a Micro-USB extension cable and a USB-A male connector from some other cable. This would at least eliminate one funky adapter.
Should be about the same for the Beagle Board but it uses a Micro-HDMI connector so it saves one adapter.
Thanks! I’m not sure about the mass thing though. Why do you think that matters?
The Lapdock male connectors seem fragile to me so I don’t want the adapters which exert a lot of leverage on the male connectors. When a phone is dropped into the dock there is physical support that keeps the phone from bending the connectors.
I also notice that some instructions talk about trimming the plastic on adapters to get them to fit, which is not necessary when it’s just the female connector without the bulk of the adapter.
One other thing I noticed on the Bionic Lapdock (I don’t have an Atrix Lapdock) is that there isn’t space for a Micro-HDMI male to HDMI female adapter _and_ a Micro-USB female to USB-A adapter to be side by side because the connectors on the Lapdock are so close together.
This is another reason why Option 2 for HDMI and Option 1 for USB are preferred.
I have a very new revision 2.0 board (code 7) and it cannot be powered by the Lapdock’s Micro USB male plug into one of the Raspberry Pi’s USB A ports. The system will boot up but after a few minutes it will shut down and apparently it’s a power problem.
So I cut the power wires (red and black) in the cable from the Micro-USB male on the Lapdock to the Raspberry Pi’s USB A female port and ran a separate cable from one of the USB-A female ports of the Lap Dock to the Raspberry Pi’s Micro-USB female power port.
You can’t power the board from both the Pi’s USB-A port and the Pi’s Micro USB power port simultaneously; you must cut the power wires going to the Pi’s USB A port.
In short, your 9/28/12 edit didn’t work for my 2.0 board. I had no other USB devices plugged into the Pi.
Thanks for this — your article helped shape my implementation of the Pi/Lapdock. Check it out! http://mschausprojects.blogspot.com/2013/07/create-raspberry-pi-laptop-with.html
Steve wrote: “One other thing I noticed on the Bionic Lapdock (I don’t have an Atrix Lapdock) is that there isn’t space for a Micro-HDMI male to HDMI female adapter _and_ a Micro-USB female to USB-A adapter to be side by side because the connectors on the Lapdock are so close together.”
Likewise, I have a Motorola 100 lapdock. There isn’t space for even one adapter and one micro cable. Both have to be micro cables. Does the Atrix lapdock have more space between the two micro male plugs than the Bionic and 100 lapdocks?
I mentioned in a reply to another comment that I removed the “dock” part of the Lapdock because I didn’t like how close together those connectors were. It’s not something I’d recommend, and it’s not necessary since you should be able to trim down the ends of the cables or adapters with an exactoknife to make them fit:
Does the Atrix lapdock, droid lapdock and 100 lapdock require a HDMI config script or an USB wifi config script or an audio script? Which lapdocks do and which don’t?
HDMI is configured in /boot/config.txt: http://elinux.org/RPiconfig
I used this setting for the Atrix Lapdock to get a 1366×768 resolution:
hdmi_mode=81I was able to get wifi working out of the box with this adapter (version 3): http://www.tp-link.dk/products/details/?model=TL-WN821N
As for audio, I can’t say as I never bothered.
Do I type hdmi_mode=81 in the beginning or the end of the /boot/config.txt?
Thanks for recommending a wifi adapter that works out of the box. TL-WN821N v3 has Atheros AR9287 chipset.
It doesn’t matter where you put that line in config.txt, as long as it’s in there.
Thank you.
I asked about needing a wifi script because the article below instructed lapdock 100 and pi model B required it. What model is your pi and lapdock? People call two different models the Atrix lapdock: the Atrix lapdock and the 100 lapdock. Does the older atrix lapdock have a model number to differentiate it from the 100 lapdock?
Thanks for your howto.
http://www.raspians.com/the-atrix-laptop-dock-100/
“By itself, the Lapdock is incompatible with the Raspberry Pi’s USB hub+Ethernet chip (Model B only) when you introduce a WiFi adapter (basically, there is a problem when you mix the Raspberry Pi, the Atrix Lapdock, and a WiFi adapter). I found a workaround by disabling the Ethernet device in software. You can test it by running this command as root:”
I think the problem that author is running into is the version of his Pi. As long as you have one newer than Model B (e.g. model B revision 1.0 + ECN0001 or revision 2.0) then you shouldn’t have any problems using the USB hub on the Lapdock. (Mine was model B revision 1.0 + ECN0001.)
As for differentiating between all the Lapdock versions that are out there, I have no idea.
I returned my 100 lapdock because the 100 lapdock and 500 lapdock require a HDMI script, audio script and wifi script. I purchased an Atrix lapdock. I used Connection 2: Keyboard/trackpad option 1: Micro USB extension cable + micro USB female to USB male adapter to the A female USB port of my pi model B revision.2.
Option 1 powers the PI. Could you please explain why you wrote: “You can use a standard phone charging cable (micro USB male to USB male adapter cable) to connect either of the Lapdock’s standard USB ports to the Pi’s micro USB port.”
Touchpad and keyboard do not work. If Option 1 does not enable the touchpad and keyboard, why do you recommend it? I waited a week for delivery. It is not cost effective to pay shipping to return it.
I have reread your tutorial and everyone’s comments several times. Still confused. I recommend rewriting your tutorial into two tutorials. One tutorial for each model pi.
Is the Connection 2+3: Keyboard/trackpad/power Y-adapter required to enable the keyboard and touchpad? If so, please specify this in your tutorial, not just in the comments. If so, I will order and wait a week for delivery. In the mean time, the return deadlines to test my pi and lapdock are ticking. If they don’t work, I won’t be able to return them after the deadline.
I reread your tutorial once again. I confused your “If your Pi is model B revision 1.0 + ECN0001 or revision 2.0, then you don’t need connections 3, 4 or 5” with not needing HDMI option 3, 4, 5. There is no connection 3. There is a connection 2+3. Do you mean connection 2+3? If so, then my pi model B, revision 2 does not need a Y USB cable. How come Connection 2 option 1 does not enable the keyboard and touchpad?
I’m glad people are helping each other around here. Unfortunately I have to approve comments from new posters, so I apologize for not getting to Dan’s comment earlier (the one right below this one).
freebirds, your suggestion to create a separate article for each version of the Pi is a good one. This article took at least a week for me to complete, including research, writing, and editing, all without pay. I will try and do that if I have time, but I can’t promise anything. Furthermore, I can’t promise that whatever works for me will work for you if you’re using different hardware.
“Option 1 powers the PI. Could you please explain why you wrote: ‘You can use a standard phone charging cable (micro USB male to USB male adapter cable) to connect either of the Lapdock’s standard USB ports to the Pi’s micro USB port.'”
If you mean connection 2 option 1, that connection only provides keyboard/trackpad input to the Pi unless you have a newer model (like you do) in which case it will also provide power. If you mean connection 4 option 1 – which is the only “option” under connection 4 – a standard phone charging cable, like the kind that comes with any Android phone (that I know of), will do. These are easy to find (where I live, at least).
“Touchpad and keyboard do not work. If Option 1 does not enable the touchpad and keyboard, why do you recommend it?”
Again, if you’re referring to connection 2, option 1 should send keyboard/trackpad input from the Lapdock to the Pi. If this doesn’t work for you, then there are several points of failure you could check. Maybe your cable is broken, or you have a bad port, or a bad connector, or a bad Pi, or a bad Lapdock, etc.
“Is the Connection 2+3: Keyboard/trackpad/power Y-adapter required to enable the keyboard and touchpad? If so, please specify this in your tutorial, not just in the comments.”
Connection 2 AND connection 3 are required for older models of the Pi. In your case, you should only need connection 2, but you can use connection 3 as well if you want to for some reason.
“If so, I will order and wait a week for delivery. In the mean time, the return deadlines to test my pi and lapdock are ticking. If they don’t work, I won’t be able to return them after the deadline.”
Aside from the occasionally helpful visitors I get (like Dan and Steve), this is not a great place for support. You should try asking on the Raspberry Pi forums, especially if you’re in a hurry: http://raspberrypi.org/phpBB3/
I apologize for being critical. I do appreciate your time and effort creating this tutorial. Thank you.
Pi powers up. HDMI works. Pibang boots. I cannot right click on the desktop to get a menu because trackpad and keyboard don’t work. I wish I knew someone else with a pi, lapdock and cables so we can trouble shoot which component is not functioning.
To troubleshoot the Pi, you could try hooking it up to a different monitor, keyboard and mouse. Or, keep the HDMI connection to the Lapdock for use as a monitor and just hook up a different keyboard and mouse to the Pi. Use an alternate power source to power the Pi, like the one I mentioned under connection 4/5.
To troubleshoot the Lapdock, you could try using it with the device it was designed for (an Atrix whatever).
Troubleshooting the cables/adapters would be tricky and most likely require the use of additional adapters. Then you’ve got even more points of failure though.
Honestly, I don’t even use my Pidock anymore. It’s just not worth all this trouble.
I am relieved to report that purchasing a Blackberry 9900 Y splitter data cable worked! Trackpad and keyboard are now functional! Apparently, the USB micro male to female cable that I purchased on Amazon that was advertised by seller1on1 for the lapdock is not a data cable. Thanks for recommending connection 2+3: Keyboard/trackpad/power Y-adapter.
The monitor turns red if I move the lapdock slightly. If I move the micro male to female DHMI cable on the lapdock, the monitor turns black again until I accidentically move the lapdock. Difficult not to slightly move a lapdock when its on my lap. I connected an eight inch male to female HDMI cable to the micro HDMI cable to make it longer. Perhaps the micro HDMI cable is too short and pulls on the HDMI plug on the lapdock. Adding another HDMI cable worked. Monitor remains black.
Thanks for your help.
I have this lapdock:
Motorola Lapdock for Atrix 4g.
I have a model B RPi revision 2.0.
I have connected them via option 1.
I connected a usb connection from the Lapdock’s port:
USB Micro-B Male (power out – data in/out)
using :
USB Micro-B Female to USB Micro-B Male cable
USB Micro-B Female to USB Standard-A Male Adapter
to the RPi’s port:
USB Standard-A Female (power In – data in/out)
The keyboard and touch pad work for me.
I also have a second RPi-lapdock set using Connection 2+3.
Everything works with this setup also.
Does your RPi power up?
Do you get HDMI display on the lapdock?
The lapdock is an external USB hub device.
I strongly suggest that anyone using an RPi with an external USB hub
do the following:
sudo aptitude update
sudo aptitude safe-upgrade sudo aptitude dist-upgrade
sudo reboot
sudo apt-get install rpi-update
sudo reboot
uname -a
You should see a verson number/date from the uname command.
It should be recent. Mine is:
Linux Dan-pi 3.10.18+ #596 PREEMPT Fri Nov 15 13:57:24 GMT 2013 armv6l GNU/Linux
To see the latest firmware date info go to:
https://github.com/raspberrypi/firmware/commits/master
If you get freezes and or communications lockups there are scripts that
have helped some of us in the past. Let me know and I will post them here.
Can this HDMI Cable be used http://www.amazon.co.uk/Nedis-Valueline-MHL-Connection-Cable/dp/B009L1UX8I/ref=sr_1_2?s=computers&ie=UTF8&qid=1399571299&sr=1-2&keywords=MHL+Connection+Cable
I don’t think so. I think it’s for connecting a micro-USB port to HDMI.
Just to let you know some good news. I have made a custom cable to connect the lapdock to the raspberry. It has on one side a Micro-usb-female, it then splits to 1)micro-usb-male 2)usb-male.
1) has only power 2) has “only data”
PM me if you would like one.
Can be bought here http://www.ebay.co.uk/itm/Raspberry-Pi-to-Lapdock-cable-/261579949544?pt=UK_Computing_Other_Computing_Networking&hash=item3ce76145e8
Very nice!
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Found micro USB female to USB male @ “http://www.amazon.com/gp/product/B00MEBEOW8/ref=pd_luc_rh_chashrec_01_03_t_ttl_lh?ie=UTF8&psc=1”
Found micro HDMI female to male HDMI @ “https://www.amazon.com/gp/product/B00KMR6XWK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1”
regarding wiggling or less than secure connections try locking the connectors in place with black or clear silicone RTV, just make sure you don’t get any inside the connections since its an insulator and will block your signals.
I’m happy to use the Pi2 and the Lapdock as a netbook for a while. But there’s one thing that’s driving me nuts: randomly the touchpad is doing weird things: mouse pointer is moving a bit by itself, and it’s hard to get it under control, because the y-axis almost doesn’t work anymore. This behaviour rests for a few minutes, then everything is back to normal. Sometimes it’s enough to switch the touchpad off and on again (if possible).
Any ideas to solve this? I’d also build in a new touchpad if I knew where to get it..
Wish I knew. I assume you’re using the synaptics driver for touchpad. Make sure you aren’t touching the thing with your palm while it boots. Beyond that, no clue.