Mk802 Android 4.0 PC + Motorola lapdock = Android Laptop

I’ve written before about the usefulness of the (now sadly discontinued) Motorola Lapdock as a screen and keyboard/touchpad interface for the Raspberry Pi.

This week I’ve been playing with the Mk802 Android 4.0 PC – which is an ultra cheap A10 Arm powered computer on a stick, and have discovered it works nicely with the lapdock to make a portable Android laptop. You can pick up one of these versatile sticks for about £40 available from amazon or ebay, although you might need to hunt around for the lapdock as they’re now increasing in price (I was lucky to get one for £50 – I’d suggest ebay or looking for one with a non-english keyboard).

The Android 4 PC came with a US 5v power adapter but there’s no need to use it – you can power the mini PC via the mini USB port on the side – presumably if you want to use this with a TV which has a powered USB port you can use the same method.

I used the cable adapter I originally put together for my Raspberry Pi – this converts the micro HDMI on the lapdock to normal HDMI (the android stick has a mini HDMI in so an additional adapter was required) and splits the lapdock micro USB to USB power-only and USB data-only cables. For added convenience there’s a power switch to click the Mini PC on and off – which is handy as the lack of a power switch is one of the Mini PC’s criticisms.

Mini MK802 Android 4 Mini PC fitted to a motorola lapdock convertor
Slightly unwieldy as the adapter was designed for a Raspberry Pi

The setup above is slightly unwieldy as I built the original adapter to fit the Raspberry Pi, but the Mini PC stick itself is very small and light so it doesn’t but a lot of strain on the connectors on the dock itself. There’s a wiring diagram on my original blog post along with a list of parts. It would be quite easy to lighten the assembly above with thinner cables – I kept the original USB female connector to make the adapter more versatile.

All together the resulting Android 4 tablet isn’t bad:

Android 4 mini PC Laptop
Most of the time the wires are hidden round the back

The lapdock’s keyboard is recognised – keys like function-home work and I’ve not encountered any mapping errors. You can also adjust the volume with the keyboard hot keys. The only drawbacks I can see is that all sound comes through the speakers – the lapdock lacks a headphone out socket –  and the overscan adjustment doesn’t quite work – there’s a narrow black border around the screen, although fullscreen video playback works right up to the edges.

The android laptop works well with most of the apps I’ve run with it – the play store is installed by default although google reports it as an ‘unrecognised device’. Some 3d apps don’t work and I imagine other more complicated apps might struggle with the single core 1.5ghz processor – but it does run angry birds.

It is also possible to hack the android mini pc to run other operating systems like Ubuntu – and to upgrade it to android 4 jelly bean, as well as adding support for bluetooth which might solve the headphones issue. It’s not going to replace my Raspberry Pi as an experimental mini PC any time soon, but as a handy web-browser and media player that I can chuck in a bag it’s quite handy.

Update: works with Windows 8 tablets too

I’ve tested the ever-useful Motorola lapdock with a Toshiba encore tablet – connected with a micro USB male to micro USB female cable, and a micro HDMI male to Female cable. The lapdock is recognised, every key works, and I can extend the desktop across both screens.

Getting a Nerdkit to work with the Raspberry Pi

Most of the things I do on a day to day basis are in relation to building websites and looking at ways to code interesting online actions – one thing I’m interested in however is the idea of the internet of things – smart, connected objects that bridge the gap between the online and actual world. Perhaps one day I’ll even find an ecampaigning application for this.

I just had a go connecting up a Nerdkit with the Raspberry Pi. Nerdkits are similar in some ways to the Arduino boards, although they’re a bit more hands on. Whereas the Arduino is nicely assembled and can be just plugged into a USB port, the Nerdkit comes as a pile of parts, a bit of breadboard and some instructions. What’s exciting about Nerdkits, Arduinos and microcontrollers (MCUs) in general is that they provide a flexible, re-programmable set of ‘brains’ with lots of interesting uses. Think of them as lego for electronics.

The ultra cheap Raspberry Pi makes a nice partner to the Nerdkit, as I’m still slightly nervous about attaching something I’ve put together myself to my shiny Mac. Along with the instructions come a set of makefiles which you compile and upload to the MCU via the USB to serial adapter.

The  Nerdkit is based around an Atmel AVR ATmega168 microcontroller which has it’s own bootloader. Also included are the crystal, various resistors, voltage regulators and a variety of input sensors and output electronics. Putting the whole thing together is very satisfying and has given me a bit more insight into how microcontroller based kits work (and what all the bits on the Arduino board do). One really nice additional feature of the Nerdkit is the lcd display panel, which provides feedback in the form of messages, poetry or temperature readouts – depending on what you program it to do. The example below shows it running as a thermometer (one of the included tutorials). Mounting the whole thing on a bit of board is highly recommended.

Photo of Nerdkit mounted on a board with a Raspberry Pi
Here’s my Nerdkit mounted on a board (an Ikea shelf panel) with power switch

Installing the software as in the user guide works fine -it’s all done in the command line, so there’s no Java based application to worry about –

sudo apt-get install avrdude
sudo apt-get install gcc-avr
sudo apt-get install avr-libc

You can edit the makefiles using Leafpad which is part of the default Raspbian operating system. Connecting the Nerdkit cable to the Pi’s USB port presented no problems either.

I did however run into a small snag – although programs would compile and upload successfully, the display on the Nerdkit was showing just on the top line:

Garbled text display
Not quite working

 A quick hunt through the forums later and I came across the fix – open the Makefile (in the example above it’s the one in the tempsensor directory and the one in the libnerdkit directory), look for the GCCFLAGS line and change the “-Os” flag to “-O0” (letter O, number 0). Then delete the .hex and .o files in both the directory your Makefile is in and the libnerdkit directory. That last bit is vital, I kept missing it.

Then it should work fine:

Normal nerdkit display
Working as it should. It was slightly chilly.

So there you go – my first steps in getting my Raspberry Pi to do a bit more than web surfing. I thought I’d highlight that the Raspberry Pi and Nerdkit work together happily, in case anyone else wants to try it out.

MaKey MaKey + Moleskine notebook + Graphite pencil = sketchy controller

As part of my ongoing kickstarter addiction I’ve recently acquired a MaKey MaKey – a sort of universal keyboard adapter gadget based on an Arduino-type microcontroller, that lets you turn virtually anything that conducts electricity into a USB keyboard or mouse.

MaKey MaKey board
It even lights up when you plug it in..

The board comes supplied with a pack of crocodile clips and a nice long USB cable – on the MaKey MaKey website there’s a list of ideas to try (apparently bananas work well as a piano). All you have to do is find something suitably conductive, connect them up with the clips, and away you go.

The simplest interaction is creating a space bar input – this Olympic hurdle game from the ONE Campaign works well as something to try.

I’ve done a bit of experimenting to see what conducts with the aim of making controller doodles in my moleskine notebook. Conductive paint from these guys works – interestingly metalic effect paint and ink doesn’t work (I suspect as the metal is in a suspension).

The easiest and most sketchable I’ve found is using a big chunky graphite pencil like this one KOH-I-NOOR Jumbo Woodless Graphite Pencil 6B available from amazon for a couple of quid:

image of moleskine jump button and MaKey MaKey
hitting the gap between the U and the M creates a space bar press

You have to press quite hard with the pencil to get a good circuit – shorting the gap between the U and the M with your finger is enough to register as a space bar press:

Playing the race against hunger game with a MaKey MaKey
Ignore my score, it’s hard to hit jump and hold a camera at the same time..

So there you are – a sketchable, moleskine portable control interface! (even if it does get a bit smudgy after extended play).

Check out the ONE Campaign race against hunger game here.

Raspberry Pi wi-fi cheat

Or ‘how to stop worrying and love WiFi’ or how to get WiFi if nothing else works – read on:

I’m calling this a Wi-Fi cheat – with the Raspberry Pi – Motorola lapdock combination I’ve been having problems getting the Edimax micro wireless adapter to work. I think it’s a power issue – the adapter gets quite hot when plugged into the USB ports on the lapdock, and I get a lot of errors on bootup – so here’s a solution:

vonets Wi-Fi bridge

It’s a Vonets VAP11G WIFI Bridge – powered off the USB on the lapdock it works fine. It doesn’t support n wireless, just b and g but it is quick enough for iplayer, most normal software installation and web surfing. I’ve had no problems getting online with my BT homehub. It’s bulkier than most of the cheap WiFi dongles available and at about £17 a little bit more expensive, but once set up it provides a portable ethernet connection to more or less anything you plug it into.

It’s handy having something to use around the home – particularly for Linux distributions where setting up WiFi is a bit complicated, or for operating systems that don’t support WiFi yet like Risc OS.  The newest release of Raspian has addressed a lot of these issues though so I’d recommend trying that first and using this as a last resort.

The bridge itself is configured through a windows app available from the Vonets site, so you’ll need a PC on hand to switch access points, and the software isn’t available for Mac or Linux.

Edit: TheSov on Reddit has suggested this: Asus WL-330N 5-in-1 150Mbps Wireless Mobile Router which is much better (supports n and has web based configuration), but twice as expensive.

Update: there is a python app for configuring the wifi bridge available here.

To boldy crowdsource, where no-one has crowdsourced before

Here’s an idea: if everyone who watched the last Star Trek film donated a couple of dollars would it be enough to fund a real space ship?

Right now on Kickstarter you can sponsor a cube sat (starting at one dollar) which is a tiny 10cm x 10cm x 10cm satellite (potentially) hitching a ride on a forthcoming falcon rocket launch. For your dollar, you get to sponsor 10 seconds of the mission and can tweet from spaaace! –  for a bit more you get to take a couple of photos using the cube-sat’s camera. Sadly there’s no space laser option.

Edit: Skycube has managed to hit it’s target! raising $116,890 of it’s goal. The team will be publishing updates at www.skycube.org

Here’s an exceptionally nerdy video from the project organisers: no it’s not an episode of the Big Bang Theory

The backers are aiming to raise $82,500 for their project to be successful – small change compared to some recent projects on kickstarter. Space-wise it’s a relatively low key mission – the sat is destined to whirl around the earth a few times, and then deploy a giant balloon to commit tidy suicide in a fiery re-entry through the Earth’s atmosphere.

This got me thinking pointlessly about how the cost of sending stuff into space would compare with the revenues from the Star Trek films. There’s a handy blog here with adjusted values.

Once you’ve got over the shock that the highest grossing Star Trek film was the really boring one, here are a few Star Trek films, and what they could have paid for*:

The average takings for a Star Trek film are about 151 million dollars.

43 million dollars will buy you a Russian Angara rocket:

56 million a (probably) more reliable Falcon 9 rocket:

94 million was what Star Trek V took.

105 million dollars will buy you a complete 3 seat Soyuz mission.

160 million dollars a nice ION drive powered SMART1 probe around the moon (or Search for Spock)

700 million dollars will send a car sized probe to Pluto (New Horizons)

820 million dollars buys Some nice Mars rovers. So here’s a really very exciting video about landing a Ford Transit sized rover on a distant planet:

1.7 billion dollars = is what all the Star Treks put together took.

9 billion = the UK trident nuclear missile programme.

12 billion = Skylon reusable shuttle: (ok this is semi-fictional, but the video pitch is narrated by Brian Blessed, which in itself is lovely)

And finally 43 billion buys you a shiny space shuttle programme.

So there you go. Space is terribly expensive. Still, the UK government could probably fund an entire space programme, make a lot of Star Trek films, and still have a lot of change over for nice things if it just cancelled it’s nuclear weapons programme.

Or the UK could even buy about 3 mars rovers for the cost of the Nimrod MR4 spy plane which was cancelled before entering service.

Where was I again? oh yes Kickstarter.

*Please take this with a big huge pinch of salt. I’d be upset if Wrath of Khan had never been made. Not so upset if they hadn’t bothered with The Final Frontier or Nemesis.

 

Raspberry Pi + ModMyPi case + Motorola Atrix Lapdock = Raspberry Pi Laptop

Much has already been written about using the Motorola Atrix Lapdock (essentially a portable HDMI monitor with a built in powered USB keyboard, trackpad and hub) coupled together with a Raspberry Pi. The Pi being powered by a micro USB makes it a suitable candidate for using it as a low powered portable computer.

You can still pick up a Motorola Atrix Lapdock for a lot less than it’s original £300 or so selling price, although I’ve noticed that prices have started to creep up – expect to pay between £60-£80 for one. There is a newer Motorola Razr Lapdock available which I believe uses the same ports, so hopefully these very useful devices will continue to be produced and supported in the future.

This week my ModMyPi case finally arrived – it’s an injection moulded click together case which is beautifully made –

ModmyPi case

I have already hacked together a cable to connect the lapdock and pi together – but I wanted to make a more portable and neater version. Plus using an HDMI micro adapter would provide a mount to hold the Pi in place, in the same way that a phone would be docked:

Here's the pi laptop mount

The lapdock provides a USB micro male, and HDMI micro male connector (note – micro not mini!). The USB provides power and data over 4 wires, and the HDMI video and sound. To marry this to your Pi you’ll need to take the power connection to a male micro USB plug, and data to a male USB plug. Most people who’ve done this modification have also broken the power connection to the data plug as a precaution. In my version, I’ve included a power switch to make it easy to turn the Pi on and off – opening the lid of the Lapdock also cycles the power. Obviously this is all entirely at your own risk.

Here’s my wiring diagram:

Wiring diagram

To do this you’ll need in addition to the Lapdock:

Edit: I’ve noticed that some of the items are listed as being out of stock – the crucial thing to search for is HDMI micro female and micro USB female to get the connectors you need  for the lapdock.

  • A micro HDMI female to HDMI male adapter / MicroHDMI = HDMI “D type” (also available on ebay)
  • Optional: this HDMI adapter pack came in useful as well
  • A micro USB female to male adapter (these are surprisingly difficult to find – ebay is often your friend here)
  • A regular USB female to Male cable (or you could use a micro USB male to USB male cable – I wanted the flexibility to use different lengths of cable)
  • A switch (Maplin or ebay) two or three pin on / off – just not momentary.
  • Something to use as a wiring box – the HDMI adapter holds the Pi in place quite nicely, so you could just wrap a bit of insulation tape round everything. I made a box out of a plastic screwdriver holder that came from poundland)
  • A wire stripper – these ‘automatic’ wire-strippers work well
  • Soldering iron and solder (soldering isn’t too hard, but a lot of people are put off by the idea of it – a bulkier but soldering iron free alternative would be to use terminal blocks)
  • Craft knife
  • Epoxy glue or (better) some Sugru to hold everything together

First off you need to get the two micro adapters to fit together – check with the lapdock and carefully trim away the surrounding plastic until they both fit together. Then glue the two adapters together, whilst they’re plugged into the lapdock. Be very careful not to glue them to the lapdock itself. Then expose the wires from the micro USB adapter – you might have to trim into the plug itself to do this. USB cables consist of red, black, white and green cables sometimes with a metal sleeve around them – you can cut the sleeve away and discard it. Be careful not to go through any of the wires themselves.

Here’s the underside of the adapter – showing the two trimmed plugs side by side, glued together with epoxy Edit: I’ve now used Sugru to hold this together – the wires from the USB adapter on the left feed into the box where all the connections are made:

underside of the adapter

Then cut your usb cable in half and expose the individual wires. Strip the ends of all your wires together. Then solder them together as per the diagram above. The power USB cable needs red and black connected – the data USB cable needs white, green and black connected. Put the switch on the red wire between the lapdock and USB power cable.

Once everything is soldered together, you can give it a quick test by plugging in the Pi to the lapdock. If everything goes ok, once the lid is open and you can boot and test the keyboard. If it doesn’t work, check the connections and that the HDMI adapter is fully plugged in.

The final result is the Pi sitting on the lapdock behind the screen.

For extra neatness you could always mount the switch on the case itself and route all the cables internally, but there you go – a practical portable Pi Laptop you could just chuck in a bag and take with you, and that doesn’t alter the lapdock in any way.

Raspberry Pi Laptop

Thanks to Chipmonger on the Pi forums for the source of the cables and Arc Software for the wiring diagram.

Update: a few tweaks

After a few weeks of use I had a few connection issues with the wires inside the adapter and the quality of the epoxy – so I resealed the unit with some Sugru self-setting moldable rubber and resoldered the connections – the Sugru also helps to avoid the potential of short circuits.

I’ve also swapped the modmypi case for the more colourful Pibow case – this is a little bit larger than the modmypi case so I needed to use a right angle HDMI adapter to get it to fit. The Pi now sits at an angle between the lapdock and the desk – thus:

Lapdock with Pibow

And finally I’ve added a Edimax EW-7711UAN USB wifi adapter (with lovely antenna) which now works out of the box with the latest (September 2012) version of Raspbian.

Updated update:

Yes this works with a Pi Zero – you can easily power the Pi and connect the keyboard and pointer using the USB rather than Power / USB port on the zero.

Control your Mac with a sonic screwdriver

I recently got very excited about the news that a company is working on a Dr Who Sonic Screwdriver remote control – a device that translates your over excited wavy gallifreyan gestures into channel changing activity on your tardis scanner or home television.

Hang on, I'll just bypass the door/system password/monster/macguffin

This got me thinking about possible ways to control a computer using a sonic, and how I might go about building an infra-red detector for my Raspberry Pi.

But it seems I don’t need to do this: there’s a cheaper and more versatile device already available –  a Sonic Screwdriver Wii-Remote (for about 7 quid) from amazon

To get this working on a Mac you just need to download a program called Darwiinremote

Switch on Bluetooth, click on discover device, and hey presto! you have a sonic controlled mac. You can map the device to any key or use it as a mouse. Powerpoint presentations will never be the same again. The only thing it’s missing is the sonic sound effect – although I have a broken sonic screwdriver which I’m going to have a look at to see if it can be a suitable donor. Next step is to try and get this working on a Raspberry Pi which could work nicely as an IR emitter for sonic controlled home / tardis automation.

Fortunately there are already a few bluetooth project related posts in the Raspberry Pi forums and IR control is possible already with the Arduino, so I’m quite optimistic. I’ll post results on here.

I have to remind myself that I’m 33 sometimes.

Dad-Tech: Wooden Raspberry Pi prototype board

This year for father’s day I bought my Dad a Raspberry Pi – as I was lucky enough to grow up in a house filled with computers,  it was nice to return the favour!

He’s working on a project to drive a solenoid-activated pipe organ using the GPIO pins on the Pi. To this end he’s started on a wooden Pi case and prototype board – since most breadboards come with a sticky-backed plastic mounting pad it’s nice to have something to mount them on, and keep everything tidy.

Here’s version 1:

Prototype Raspberry Pi development board

(I’m trying to encourage him to keep a blog of his progress!) 

And here’s the board varnished with the breadboard in position (and some very tidy cabling from the GPIO pins)

Raspberry pi development board with breadboard and some LEDs

 Ultimately these should be available to buy on ebay, he also makes excellent clocks.