I made a Raspberry PI Laptop

I get pretty much bang on 5V at the dock connector (well at the end of a short piece of cable) even under load and slightly over 5V on the rear USB ports.

I've got 5.06V out of the dock connector which I'm using to power the pi. My question was more towards the voltage across TP1 and TP2 on the pi itself since I'm getting sticky keys (especially while trying to login) once I've booted up. I've read this is sometimes due to low voltage and was wondering if splicing my own cable (making it shorter and with less adapter connections) will help.

What kind of voltages are you guys getting to the pi with this setup?
Right now I'm getting 4.74 from the lapdock battery. I used a couple extra adapters in my setup rather then splicing cables.

You not backwards powering the PI from the USB peripheral ports are you?

Earlier on it was stated that a custom USB 'Y' cable that took the output of the LapDock micro USB port and sent the power wires to the micro USB and the data lines to the full size USB.

I'm not. I have one of these and have cut the 5v on a short extension cable coming out of the port with data. The power-only side goes to a micro usb adapter and then into the pi.

@ King: You are losing voltage due to the longer wire lengths and the resistance of the adapters. @Hetman has almost as minimal wire as you possibly could get and no adapters.

@ King: You are losing voltage due to the longer wire lengths and the resistance of the adapters. @Hetman has almost as minimal wire as you possibly could get and no adapters.

Thanks for that. After I read your post I read his again and realized he said he got that under load.

Well two weeks after seeing veryevil's post, all the parts have arrived from china and parts more local here in the UK. Half an hour with a soldering iron and I'm typing this on my PI-top.
Have to say thanks to all the posters on here for the tips on HDMI, sound etc, I don't feel such a Linux newbie either.

[Davespice]

Hi all, I have just successfully repeated what Veryevil did and have put a post about it up on my blog.
http://blogs.arcsoftwareconsultancy.com ... pi-laptop/

Nice post Dave. It's good to have clear instructions that everyone can use.

Nice post, but I have a question. Why did you make that USB so long? you could wrap it around the Lapdock!.

Many people have been having voltage drop problems with the RasPi. This usually manifests itself as keyboard and mouse problems. A shorter cable helps reduce this. With an adapter and a long cable some people may have trouble. This depends on the quality of the cables. Not being critical just thought it should be brought up for those that going to follow you, Like Me.

Lap dock is on the way, micro to HDMI adapters on the way. Now if they would just get here

Noticed you carried ground to both connectors, very smart. Any of you thought about, or have tried a USB HDD with this setup yet?

I am looking forward to a portable RasPi.

Any of you thought about, or have tried a USB HDD with this setup yet?

I'm working on a shallow, flat case the size of the footprint of the lapdock that will contain the Pi board, a powered USB hub, a USB laptop HDD, and stub cables routing all of the Pi I/O connections to port connectors at the back of the case. I'm poring over materials sources in on-line catalogs like McMaster-Carr trying to find something as light and cheap as possible (so, carbon fiber is out). However, it needs to be able to provide rigidity by having interlocking channels (or other structures) along the edges so that no tools or fasteners would be required for assembly.

It also has to be non-metallic so that it can be worked with simple hand tools as I have to work on this kind of project late at night and can't use power tools that grind or otherwise make significant noise - non-metallic materials also avoid accidental short circuits, ground loops, etc. It would be nice if the color closely matched/complemented that of the lapdock, so, a dark gray would work, which is fairly common for such materials, fortunately.

My Lapdock arrived today. I just need the HDMI adapters now. I will start building the "Y" cable while I am waiting.

[Davespice]

That's a good point. I only made it so long in case I messed up with the soldering, so I would have plenty of cable to try again with. I do intend to make the cable shorter though and to maybe put an inline switch in.

@Davespice: Thats also a good point. My cables are so short that I only get one chance.

I modified the lapdock I bought so that I can now connect the Pi directly to it.
Here are some pics: https://picasaweb.google.com/tatarandrei/RaspberryPiLapdock?authuser=0&feat=directlink.

With the number of lapdocks being snatched by members of the RasPi community... makes me wonder how long before we see a case design that couples with the factory lapdock connections (with a bit of port re-routing kung-foo)?

With the number of lapdocks being snatched by members of the RasPi community... makes me wonder how long before we see a case design that couples with the factory lapdock connections (with a bit of port re-routing kung-foo)?

That probably will happen. But the price is bound to go up for the Lapdocks.

I got my Bionic Lapdock last week from a local Verizon shop. They are out of stock online but you might be able to find one in the local stores. After getting the HDMI cables and building the Y USB cable mentioned in this thread everything works like a charm!
I did most of the testing with Openelec. The first battery charge lasted for over 7 hours! I only had the Raspi and a USB stick connected.
Brightness and volume can be adjusted from the keyboard. When I press the Fn + "Speaker" key the volume can only be turned louder. BUT! I found that the F9 and F10 keys can turn the volume up and down!
When I close the lid the power goes away for about 2 seconds then it comes back on. The same thing happens when I open the lid. This is a bit annoying and I would prefer to replace that switch with a "real" on/off switch. Did anybody find out where that switch is located? On the other hand it seems that removing just the micro USB plug does not turn the lapdock off. The LEDs on the trackpad and the caps lock stay/turn on.
My primary use for this "Rasptop" will be ham radio operation. I intend to use it for digital communication and logging. As a side note: If somebody knows a good logging software for the upcoming FD please drop me a mail at my call @arrl.net. Of course it must be able to run on the Raspi.

Hermann, AJ4ZS

Got mine all set up - However a spanner has just hit the works.........

I was hoping to use this setup as a nice 1080p portable video unit - but using headphones via the Raspberry Pi's onboard analog jack is hideous. Really poor quality as it picks up electrostatic from nearly everything on the board.

So I'm scratching my head wondering how I can take HDMI audio from the dock to headphones.

At present I haven't seen any positives in using a usb 2.0 soundcard as they're performing just as badly on the Pi at present -

So for now it IS a Raspberry Laptop - just not quite the portable home cinema I hoped it would be.

If anyone has any work rounds / config.txt updates that may offer some improved audio quality I'd welcome some input

Justin

So I'm scratching my head wondering how I can take HDMI audio from the dock to headphones.

If you feel like doing some hardware hacking, I guess you could replace the speakers on the lapdock with a headphone jack? I dunno if the voltage-levels would be compatible though...?

So I'm scratching my head wondering how I can take HDMI audio from the dock to headphones.

If you feel like doing some hardware hacking, I guess you could replace the speakers on the lapdock with a headphone jack? I dunno if the voltage-levels would be compatible though...?

Hmmm That's a pretty good idea Andrew - gonna take a look at the teardown stuff on the net before I start ripping it apart.

I'm wondering if I could somehow use a bluetooth dongle and headset to channel hdmi audio out of the Pi ???

Either way - I'm possibly asking too much of the project for what I have paid out to get it together -

Its not everyday you get to make a 1080p laptop with 7 hours battery life for £120

I'll prob end up using a portable headphone amp in the setup and just get by.

I will deffo have to get this all boxed up properly tho - can you imagine me taking it on my daily commute via train to London with all this hanging off the back of the Lapdock.

Something tells me I'd get a few hearts pulsing setting this up in 1st class during the Olympics! lol

gonna take a look at the teardown stuff on the net before I start ripping it apart.

Ripped mine apart over the weekend (using the teardown video as a guide) and it was much easier than I was expecting. Only mistake I made when reassembling was using the "long" screws to reattach the keyboard to the base, which left the short screws which were too short to go in the bottom of the case! But after removing the screen again, swapped the screws over and it all went back together fine. And still works!

I'm wondering if I could somehow use a bluetooth dongle and headset to channel hdmi audio out of the Pi ???

Never used bluetooth audio, but I wonder if it might suffer the same problems as USB audio?

Its not everyday you get to make a 1080p laptop with 7 hours battery life for £120

The RPi is capable of playing 1080p video, but the lapdock screen is 720p. Just to nitpick

Its not everyday you get to make a 1080p laptop with 7 hours battery life for £120

The RPi is capable of playing 1080p video, but the lapdock screen is 720p. Just to nitpick [/quote]

Ah yes but its still capable of playing 1080p in hardware = for me not having multiple MVK's laying all over the place to match various gadget specs - just 1080p throughout the house. For £120 there isn't anything out there that can do that for over 7 hours with a screen regardless of resolution

Justin

Something tells me I'd get a few hearts pulsing setting this up in 1st class during the Olympics! lol

First class commuter? You should have a MacBook Air!

Something tells me I'd get a few hearts pulsing setting this up in 1st class during the Olympics! lol

First class commuter? You should have a MacBook Air!

See also: this post viewtopic.php?p=93151#p93151 and the ones immediately underneath it

If you feel like doing some hardware hacking, I guess you could replace the speakers on the lapdock with a headphone jack? I dunno if the voltage-levels would be compatible though...?

If that works but has trouble driving your headphones, there are always plenty of "economical" tiny devices that solve this problem. Headphone power from phones has always been less than ideal and plenty of solutions are on the market. Here is one:

http://www.amazon.com/Firestone-Audio-F ... B005WKHDLC

I modified the lapdock I bought so that I can now connect the Pi directly to it.
Here are some pics: https://picasaweb.google.com/tatarandrei/RaspberryPiLapdock?authuser=0&feat=directlink.

godFather89

I like your adaptation gets rid of all of those ugly cables. I might do this myself.

What HDMI connector did you use. Did you cut a standard cable and solder it to the micro hdmi contacts ?

Looking at the pictures that is exactly what he has done. That's a full sized HDMI plug poking out of it. Underneath the cover, the plugs sticking out of the Lapdock are on flying leads and can easily be moved, if you're OK with hacking the case. He's also connected one of the USB data lines to the power socket (you can see the wire crossing the Pi) so it just needs one additional plug (not two as in the "classic" Lapdock Y cable.

For my part I'm not sure I want to hack my Lapdock up like this, although I do think it is the neatest solution yet. I'm concerned about resale.