Friday 28 March 2014

Three New Products for Friday!

Three new products in store today as well as some notable restocks. First up is the blinkiest of them all - the 15 NeoPixel Ring Segment!
Unusually for Adafruit we're going to have to get the camera out. The image above is a bit of a blur while the lovely lit image below shows four of the product in action, which is a little misleading in my opinion, not intentionally but combining that with the official name of NeoPixel 60 LED Ring 1/4 Segment you can see how folk would get confused!
 
You'll agree a beautiful product. If you've been living under a poorly lit rock for the last 6 months you might want be wondering what a NeoPixel is. Well NeoPixel is a trademark of Adafruit it's their name for a whole bunch of products built with the fabulous WS2812 and WS2812B LEDs from WorldSemi. The WS2812 has an integrated controller chip within the LED package. It still needs to be told what to do but the protocol is fairly simply, if time specific. They need a microcontroller like an Arduino to drive them really.
Next up we have a new servo! This is the step up from our 9g hobby servo weighing in at about 15g due to its metal gears! I've been using a lot of servos lately and keep coming across times where a bit more torque is needed, so that's the niche these fill. For where you need a like for like replacement for a resin gear servo with a bit more grunt. I got the screwdriver out so you can have a look under the hood.
Like it's lighter cousin it comes with a set of "horns" and fixings so you can attach it easily where it's needed. Take a look at the listing for details of how to run this fella from a Raspberry Pi or Arduino.
The last new product is the Ultrasonic Distance Sensor! This a great and low cost sensor, perfect for the nose of your robot or for a haptic feedback glove. With a range of 2cm up to 5m with an accuracy of +/- 3mm it's extremely versatile for the price of just £1.99. Again it will work on a Raspberry Pi or Arduino. We include a couple of resistors so the 5V logic that it kicks out won't fry your Pi (as long as you use them!). What more would you want? Picture of the product with a 10p coin? Yup got that too.
If you check out the listing there's some more info and also evidence of how cold it was in the office today, I couldn't bring myself to take off my miser mits for the photographs!
I'll be quick with the restocks... we got a whole bunch of these:
an handful of these:
more of these:
Oh these too!
and these:
These....
and not forgetting THESE!!
That's it for tonight!

Wednesday 19 March 2014

Single Sided PCB Arduino Clones

Now those that know phenoptix board will know it's an obsession of mine to avoid vias. Single sided is best but I can rarely achieve it. The first version of the Cylon PCB was actually single sided but having to alternate the polarity of the LEDs as you inserted them was going to cause some problems. Doing single sided boards is fairly difficult, so they always impress me when I see them. This morning I spotted this by way of theelectronics-lab blog - the Nanino by Johan von Konow.
You can see straight away that it's beautifully laid out. The tag line is that it is DIY friendly but there are too many holes for my liking in that prototyping area if I'm entirely honest. It does however give or shall we say represent, as nothing is given (BY-NC-SA!) a simple one sided Arduino compatible PCB. This has of course been done before, and it would seem by people who understand licencing. The Aryduino is another great looking board and actually acknowledges the copy left licence that Arduino is released under.
I had intended to write this whole blog about the Nanino but the licencing has really annoyed me. The Aryduino has power management anyway which makes it much better. Dr. Ayars lists the pros and cons of his board as follows
Hoo-ah:
  • Standard Arduino form-factor and mount-points.
  • Accepts standard Arduino shields.
  • Single-sided board, easy to make with toner-transfer method. 
  • 16MHz ATmega328.
  • No SMT parts.
  • On-board 5V regulation.
  • Screw-terminal power-in connector, rather than barrel jack.
  • Pin-13 LED.
Meh:
  • Lacks on-board USB-Serial conversion, so programming requires an FTDI cable.
  • No 3.3V regulator.
  • This is as detailed a board as I ever want to make using toner-transfer.  
  • No TX/RX LEDs.
  • No ISP connector.
  • Three component-side jumpers. Couldn't quite get all traces on the back side!
Which is a really fair and honest appraisal. His does have three jumpers but that's still pretty good with so many components. The populated boards have a sort of "fun" look about them, it's probably the detail of using different coloured jumper wires. I tend to use resistor and LED legs for that particular task!
The Eagle files have been shared too, again unlike the Nanino. Making the Aryduino a really very nice Open Source project. That is worth celebrating. It's a real shame about the Nanino, Johan you've let yourself and Open Source down. Copy left you dufus! Probably a little strong but I'm getting fed up of celebrating sudo Open Source or Fauxpen Source projects. We need to start calling BS on some of these. /rant
These aren't the first single sided Arduino boards to have existed but what I have seen this morning. More can be found on the Arduino forums and via the magic of google!

Monday 17 March 2014

New Products for Mid March!

We've just got in a bunch of new products, and they can all be found here on our New Products section. Most of them are requests from customers, so we should sell at least one of them! Others are products that I've been curious to play with for some time now, so watch out for more in depth posts coming up.
The first of the customer requests is this Galvanic Skin Response sensor or GSR. GSR is a method of measuring the electrical conductivity of the skin, which varies with the moisture, caused by sweating! Since sweat is controlled by the sympathetic nervous system it's measurement can be used as a measure of emotional and sympathetic responses. They are therefore commonly used along with a few other methods in lie detectors, e-meters and would no doubt make a good addition to your Voit Kampff machine. Shown below being used in conjunction with a Grove Shield, Grove Connectors, Grove Buzzer (we don't stock that yet!) and a Seeeduino (Arduino clone that we've just restocked).
It comes with the finger clots shown and you don't need the grove system to use it. It connects as a standard analogue input on an Arduino and can be used on a Raspberry Pi with an ADC (Analogue Digital Converter). 
Looking next at our first Bluetooth Low Energy module, from Seeed Studios. Reading the blurb I've copied straight from Seeed I'm quite amused to see that it's sudo jibberish, I did first write complete jibberish, but that wouldn't quite be true. Lets try and pick the nuts out of it anyway.
It's based on the CC2540 Bluetooth low energy chip from Texas Instruments. Grabbing some of the info from TI we can see that its a true single chip solution capable of running both application and BLE protocol stack and includes peripherals to integrate with a wide range of sensors etc. Beginning to see why the Seeed text is gibberish now... the user guide for the chip is 353 pages long. I've linked both the big guide and also the datasheet:
Really the important things to note with this module is that Seeed have broken it out into the standard XBee format so classics like the Adafruit XBee breakout will work with it as well as all your favourite shields will work. You'll get about a 50 meter range and you should be able to interface easily with your Android or Apple based telephone choice. I'd like to test these on my Nexus some time soon. If I've not updated the copy and paste listing in a week or so please give me a nudge!
Moving on we have the Rainbowduino, a creatively named Arduino compatible with an on board LED driver so you can drive (by which I mean source the current as well as control) 192 LEDs. That's a 8 x 8 RGB Matrix or 4 x 4 x 4 RGB LED cube! Projects for the near future I think! I do have a small stock of 8 x 8 RGB Matricies looking for a home! This is possible as the ATMega328 is complimented by a couple of LED drivers right on the board. On uploading the image below (again from Seeed) I've noticed that it is in fact four 8 x 8 RGB Matricies, which is beyond the capabilities of this board!! These four are being driven by what would appear to be I2C - A0 and A1 on the Rainbowduino and a separate power feed. Naughty Seeed, and of course me for perpetuating this slightly dodgy marketing!
Sticking with RGB blinky goodness - we picked up some WS2812B LEDs from Adafruit, these are the "secret sauce" behind all of the NeoPixel products that come by way of Adafruit.

They're the latest version of the LEDs with an integrated WS2811 microcontroller which does all of the hard work! These have reverse voltage protection and also a constant current driver for the LEDs. You actually don't need external choke resistors on these, as was previously reported on the WS2812 LEDs. They're rolled the voltage source for the IC and the LEDs into a single Pin now so we're down to 4 pins on the LED. It's all covered in the Datasheet which is available here:
Now for another item I plan to test on my phone! Inductive charging sets! These appear pretty simple to use, as it's an Adafruit product the write up and explanation is pretty good and I'll only add to it when I try with the coil in the Nexus. Watch this space! 
Another great product by way of Adafruit next, the Midnight Hacker! This is a tiny Leatherman ES4 Squirt with wire strippers. I've had the pliers version for a good few years now and they are a robust and extraordinarily useful tool, which can get you into trouble if you're not careful. Read the full embellished description if you want to know why. If not quickly snack on the tasty images from Adafruit below
   
One last product for this post by way of Adafruit, one that I've quite fancied for a little while. The Adafruit PCB Ruler. This handy 6 inches of FR4 contains a great many of the most popular SMD footprints as well as trace widths and wire gauges, it is all Imperial but you can't have everything right?
As with all our product we'd really be grateful of your feedback and suggestions, and most of all we'd be grateful of your orders! Thanks for reading this far, there are a few more to cover but I'll save that until the morning.
TTFN
Ben

Wednesday 12 March 2014

Hackaday Projects goes live to the public!

Having been one of the fortunate few to have had a sneak peek at the late closed Alpha of Hackaday Projects I would say it's definitely a website to visit and visit often. It's already jam packed with great projects, that you'll probably see there first as they're often not completed at the time of publishing.
It's my belief that this site fills a yet unfilled niche in the hacker / maker world. Somewhere to actually work on projects, rather than a pedestal to put your shiny finished products. Sites like Instructables and Thingiverse put you in the part of the creator of a thing who wants to share it. Hackaday projects puts you in the place of someone working towards a thing, where people can help you out along the way with a kind word or even collaboration on your project. It's like a big online hackspace where everyone is working at their own bench but every now and then look over and say, "hey that looks cool" or "want a hand with that?" or quite possibly "why on earth are you doing it like that?" or "whoa! You're going to lose all the fingers on your left hand".
The site is new so expect a few glitches and for it to be a bit clunky at times, but it seems that the team working on it are doing so proactively and there are improvements happening all the time. They've also just launched a competition, which is something we all love! To build something SciFi themed with a collaborator. I do have an idea in mind...
If you do decide to stop by please check out my page, I'll be working on some projects on there and posting up the details of some of our previous ones too. I am hacker number 654 or there's this link if you prefer.

Friday 14 February 2014

Plotting Time - Open Source Clock - Plot Clock

Some days you get into work and find out someone has made something awesome. Those are good days. When that thing is Open Source it's an even better day. This is one of those days. 
Jonnanes of the Nuernberg Fablab has created the plotclock. The plot clock is built from 3mm Acrylic or can be 3D printed and consists of three 9g servos controlled by an Arduino Uno. Two servos control the arms that hold the pen and the third lifts the arms and therefor pen from the surface. The files for the machine can be found on thingiverse along with the code, the code is also in GitHub so it's double OpenSource. The Build instructions are available on the Fablab site as linked in the first sentence of this paragraph.
After some tinkering and breaking of parts we've got it together. No joy on the wiper part yet but it's a work in progress. All of the parts we broke we redesigned a little so clumsy people like our good selves don't snap them too. This was mainly increasing hole sizes slighty so self tapping can be used, which actually makes the build super easy. There's an edit to the left and right arms too, where they attach to the servo, making it easier to attach. All of the edits have been uploaded and cross referenced on Thingiverse

Wednesday 12 February 2014

When is a Pi not a Pi?

Well when it's an Arduino compatible of course! Spotted by the eagle eyedRecatha this robot based Kickstarter seems to have got confused, or are cynically skirting the Raspberry Pi Trademark to sell a few kits.
Lets apply Hanlon's Razor and say it's a mistake and they've not heard of the Raspberry Pi we can then draw our focus to the Arduino Compatible board that ships with the robot. It's clearly based on the Uno and says as much in the blurb but the image that we can see only has the Kickstarter company's details, no attribution is visible, we only have 50% of the evidence available at the moment so lets not speculate any further until we see the whole thing!
We look forward to seeing how this pans out and wonder if there will be any fall out from "the Foundation" regarding the use of Pi in the robotics and electronics field.

More on the Cambridge Pi Jam

Now that the dust is settling it seems that other participants (and organisers) are getting together their thoughts and media on the 5th Cambridge Raspberry Pi Jam which took place on Saturday the 8th of February 2014. Youtube videos and blogs are popping up all over the place and frankly I'd like to watch and read them all! I'll try and keep them together on this post so it may evolve over the next week (or day).
First up is this funky short from Michael Horne (aka Recantha) just look out for flashing lights and you'll spot us!

Next up we see the whole day pan out right from set up. We're top middle right, you'll see the flashing lights switch on at about 30 seconds in. It was a really great day, seeing crammed into 6 minutes is quite fun.
Last up we have charwarz blog who sums up why she didn't by a Cylon kit. If only she'd known that it would have taught her about Charlieplexing as well as being the ocular display of a robot killing machine...
I may be repeating myself in saying the Raspberry Pi Jam was great. You should see if there's one near you. Check out the PiJam uberwebsite for details! I'm looking forward to seeing more reports as the week rolls by as well as catching up on all the cool stuff I missed whilst manning the stall via the PiJam Youtube channel

It's all about the Benjamins

Looking around at my chaotic desk and the scrawled on day book and notice board front and left of me (respectively) I often think I should be more organised. 
A man who did get a lot done is Benjamin Franklin. He invented Bifocals, lightening rods, was a founding father of America, had an illegitimate son and even got his face on the £100 bill.
This was a man with a plan, a daily plan it would seem, according to lifehacker
Further to his daily plan he lived by 13 virtues:
  1. "Temperance. Eat not to dullness; drink not to elevation."
  2. "Silence. Speak not but what may benefit others or yourself; avoid trifling conversation."
  3. "Order. Let all your things have their places; let each part of your business have its time."
  4. "Resolution. Resolve to perform what you ought; perform without fail what you resolve."
  5. "Frugality. Make no expense but to do good to others or yourself; i.e., waste nothing."
  6. "Industry. Lose no time; be always employ'd in something useful; cut off all unnecessary actions."
  7. "Sincerity. Use no hurtful deceit; think innocently and justly, and, if you speak, speak accordingly."
  8. "Justice. Wrong none by doing injuries, or omitting the benefits that are your duty."
  9. "Moderation. Avoid extremes; forbear resenting injuries so much as you think they deserve."
  10. "Cleanliness. Tolerate no uncleanliness in body, cloaths, or habitation."
  11. "Tranquility. Be not disturbed at trifles, or at accidents common or unavoidable."
  12. "Chastity. Rarely use venery but for health or offspring, never to dullness, weakness, or the injury of your own or another's peace or reputation."
  13. "Humility. Imitate Jesus and Socrates."
So that my friends is how you get things done. I'd struggle with 2. I'm chatty. 3. You really should see my desk and for that matter so should I, alas it is covered by a great number of half finished projects and coffee cups. Perhaps I'll clear it a little and find places for things. 6. Better uninstall Ingress from my phone again. Would be happier doing that when I hit level 8 though, that harks back to 4. 12. Benjamin didn't do so well with that one it seems.

Tuesday 11 February 2014

10 Minute Open Source Test


I've devised a simple test to see if an Open Source project is actually open source. Give yourself ten minutes. Try and find the files for the source of the project, that's the Cad files or code that allow you to reproduce the work - pdfs of board layouts do not count - open software does not provide jpegs of code.
If you can't find them in that time frame then the project isn't Open Source. If the project says it's going to be Open Source in the future then it's not Open Source yet. It's closed. Then if it says it is open and you can't find the files, email the project lead and ask where to find the files they may not have been published due to oversight - apply Hanlon's Razor.
Where you can find them, are you allowed to use them without restriction other than you attribute and not close the product? If not it's closed. A conversation has already been started regarding non-commercial licences. In my opinion these only serve as "douche bag" enablers, the only people who won't use your software / hardware are people who respect the licence. Douche bags will use it and profit from it. You are giving them an advantage over the good guys.
Then what? That's the bit I don't know, there's a lot that claims to be open that isn't and I think that hurts the community.

Pat Delaney - The Concrete Lathe and the Engine Mill

I had the fortune to meet Pat at the Open Hardware Summit in 2012. Pat's hardware was the hardest there, it was concrete. Pat had rediscovered a method of making machine tools cheaply and was at the summit to share it with us. On Make he's sharing the concrete lathe, his engine mill and his philosophy. It's well worth a read.Make Article on Pat Delaney there's also a great deal of info atOpenSourceMachineTools.org
"This is the story of Pat Delany, one of the leading creative voices in Appropriate Technology — technology that is small-scale, decentralized, labor-intensive, energy-efficient, environmentally sound, and locally controlled. This 78-year-old grandfather came to the field as an outsider, inspired by a second-hand description of a news photo. But his visionary home-built machine-tool designs now have the potential to help millions bootstrap themselves out of poverty. Delany never had much money himself, or any formal engineering education, but his personal quest to develop open-source DIY machine tools has been embraced and spread by Appropriate Technology’s conference-hopping, grant-getting establishment."

Monday 10 February 2014

Dyson invests £5m in Domestic Robots

Sir James Dyson is investing £5,000,000.03 in Imperial College London's Robot Vision Lab, who set out their stall on their fantastic website that is actually full of content, links and actual research rather than the single image slick websites we've seen of late. There's even a software section and links to github of Alumni Hauke Stradat.
The group head, Professor Andrew Davison, is a pioneer of Slam (available from the github link above) or simultaneous localisation and mapping. Where a camera is used to make a 3D map of the visible space and is to be used as the only environment sensor on a robot, compare that to the Roomba, which uses a contact sensor, IR distance sensor and "cliff sensor" (which is another IR distance sensor) to avoid drops.
Combining this software and camera approach with Dyson's experience with motors and electronics they hope to build a new generation of domestic robots. 

Saturday 8 February 2014

CamJam Download (long and unnecessarily detailed)

Today I attended my first "Pi Jam", CamJam or the Cambridge Raspberry Pi Jamboree. Since arriving home I've had a long chat with my wife and now she's headed to bed and I'm unwinding with an Ubu beer and an episode of Myth Busters, downloading the days thoughts to the blog.
It was a 5:30 am start, which isn't unusual of late, what with the boy's sleeping habits. With no prior knowledge of the format I had mentally prepared for a Maker Faire style day, fielding questions non-stop from all angles from doors opening to closing time. The usual pre Maker Faire preparation ensued, filling up the car in the dark, buying bottled water and snack bars for the day (if it was good enough for Luke on Degobah...) and some RedBull for the journey home. Each item purchased separately to stock up on £5 notes and £1 coins for change later in the day. I was set.
The journey down wasn't too bad, stopped just outside Cambridge for the last substance I expected to consume for the day. For a change I was in good time, which was lucky, as I was about to take the scenic route through the beautiful city that is Cambridge. Junction 13 was closest to the CamJam venue, but it's an unusual one in the UK as you can only leave at it going north bound. As I was going south, I just needed to take the 7th right after leaving the dual carriage way, follow the road through, turn right and watch out for the observatory turn right and I was there. Or was that the 8th right? Nope the 7th. But already I'm in the city, and it's a beautiful city. Architecture like you wouldn't believe. Green spaces everywhere. Road signs that only tell you about bikes and the colleges in the city. Next my phone battery was dead depriving me of accurate location services, the MacGyver in me was mentally using a buck converter direct off the car battery to charge the phone when I discovered the in car charger. Day saved and I arrived at the venue, still first of the vendors I think!
Well what a spot they had picked out for phenoptix, first seen on entry and three tables! Very glad I went full tilt on the blinky and brought a tonne of stock with me! I really had a lovely welcome, from familiar faces met in person for the first time. The most enthusiastic welcome was from Aideen who'd won a BeagleBone Black our newsletter giveaway. The warm welcome set the tone for the day. It was all so friendly. For set up I decided to go for blinky, then plushie, then a smattering of tech with the big box o'sensors at the end of the table for the real enthusiast to look through. Setting up at events like these is a mix of fun and conversation and fear that you'll not be set before the hoards descend. I'm not sure if ready was ever an option for me at the Jam but set was ok!
However rather than a hoard, the CamJam participants arrived seemingly from nowhere in small groups, politely mesmerized by our display of colour changing LEDs. The questioning that followed has prompted me to spend more time with the WS2801 datasheet! What was great is that everyone arriving was headed to the lecture theatre and passed all us vendors with curious conversation, eager to come back and explore more. With a great day of programs planned and scheduled breaks for coffee and browsing electronics nobody seemed rushed. After each session groups would come out, explore our stock, ask questions and even buy some stuff! It was really nice to be there as a vendor, I felt as if I was there to sell but also share knowledge and experience (the very little I have!) as well as to learn from the participants. The stuff I had to show was there as a bit of an extra rather than a "maker veneer" as it sometimes feels at Maker Faires. Last year I attended a lot of Maker Faires and in some cases there were more vendors than makers and it all felt a bit off. At CamJam, it all felt very nice.
The lectures gave us vendors a chance to chat and mingle a little too, which again is a bit alien to me. I even had chance to take some poor quality mobile phone shots of my fellow vendees. A really fantastic bunch.
It was great too putting so many names to faces, when I say names I pretty much mean twitter handles. I'll try and list everyone tomorrow. I suppose overall I enjoyed the feel of the CamJam, it was a really nice event and I felt privileged to be attending. It would be great to go again. There was even cake. I'll wrap up now before I type I again. Tired and unedited this thought stream for the day has been downloaded! Maybe something more concise will follow, probably not knowing me. 

Voronoi Boxes from NYC Resistor!

Just spotted this by way of NYC Resistor
This is a Voronoi box. The pattern is a Voronoi tessellation. I've seen these beautiful patterns before but never known what to google. This box was made by Trammell Hudson of Resistor who has kindly shared a couple of scripts to generate the patterns on his bitbucket as well as another to generate some cool circles.
Check out the original post for all of the the beautiful details. I'm about to fire up the laser and add some LEDs...

Friday 7 February 2014

Guided Tour of the Adafruit Trinket

Arriving at phenoptix towers this morning we noticed that a someone had searched the site for the trinket pinout. You might first ask what a Trinket is, well a Trinket(TM) is a teeny tiny ATTiny85 breakout from Adafruit and is available in two flavours 3.3V Logicand 5V Logic.
Despite its diminutive size the Trinket is a very useful bit of kit and has found a lot of uses in its short lifespan, thanks to the ease of use provided by Adafruit and their update to the Arduino IDE. You can also program it by our favourite programAVRDUDE! So I mentioned many uses, like what I hear you ask. Well like this:
(making a light ball thing)
https://www.youtube.com/watch?v=TzzAmB3E3ok&feature=youtu.be
(making a chip tune FM Transmitter - apparently with Rick Roll capabilities)

(driving NeoPixel strip! - now you're interested right?!)
So now you know what it is and what you can do with it, here's the good stuff. The Pinout (I would say Pin Out but I don't know what would be correct. Feel free to correct me in the comments.) 
The diagram was provided by two cool folks in the Adafruit forums - ardunaut and the TheKitty. For a more technical view you might want to check out this schematic
Frankly we're most interested in the GPIO pins right? Well on the Trinket Tutorial over on the Adafruit learning system Ladyada explains

All the GPIO pins can be used as digital inputs, digital outputs, for LEDs, buttons and switches etc. They can provide up to 20mA of current. Don't connect a motor or other high-power component directly to the pins! Instead, use a transistor to power the DC motor on/off

On a 3V Trinket, the GPIO are 3.3V output level, and should not be used with 5V inputs. On a 5V Trinket, the GPIO are 5V output level, and can be used with 3V inputs but may damage electronic devices that are 3V input only!

The first 3 pins are completely 'free' pins, they are not used by the USB connection so you never have to worry about the USB interface interfering with them when programming
  • GPIO #0 - this is connected to PB0 on the ATtiny85. This pin can be used as a PWM output, and is also used for I2C data, and SPI data input.
  • GPIO #1 - this is connected to PB1 on the ATtiny85. This pin can be used as a PWM output, and is also used for SPI data output. This pin is also connected to the onboard LED (like pin 13 on a regular Arduino).
  • GPIO #2 - this is connected to PB2 on the ATtiny85. This pin can be used as an analog input (known as Analog A1), and is also used for I2C clock and SPI clock.
The next 2 pins are also used for USB programming. That means that when the Trinket is connected to a computer and in bootloader mode or in the middle of uploading a new program, they are used for sending data to/from the computer! It's possible to share these pins if you are careful. The best use of these pins is as outputs to things like LEDs , or inputs to things like buttons and just make sure not to press the buttons while connected to USB. We didn't want to keep these pins off the board but we strongly recommend not using them unless you're sure you need them since you might have to disconnect any connections to reprogram the Trinket!
  • GPIO #3 - this is connected to PB3 on the Attiny85. This pin is used for USB programming, but its also an analog input known asAnalog A3
  • GPIO #4 - this is connected to PB4 on the Attiny85. this pin is used for USB programming, but it can also be used as a PWM analog output and an analog input known as Analog A2
The rest of the details are equally well explained so check it out on their fantastic learning system.
You should now be able to find the Trinket Pinout and see what a great little product the Trinket is. Even if you're not into off the shelf electronics you can build one yourself, very cheaply! It might not be quite so handsome though! 
Want to buy one right now? Click here!