Download Mixtape vol. 13 – “Trees” and/or subscribe in iTunes.

Tracklist:

1. Todd Terje – Snooze 4 Love
2. D.L.i.d – Colour in Your Hands (feat. Fink)
3. Taylor McFerrin – Awake to You
4. Clams Casino – I’m God
5. Starkey – 11th Hour
6. Casino Times – That’s the Truth
7. Deap Vally – End of the World
8. Maya Jane Coles – Little One
9. De La Soul – All Good (feat. Chaka Khan)
10. Jimmy Ruffin – Tell Me What You Want

And yes, Taylor McFerrin really is Bobby McFerrin’s son!

This document was on the W3C Recommendation track but specification work has stopped. The specification reached an impasse: all interested implementors have used the same SQL backend (Sqlite), but we need multiple independent implementations to proceed along a standardisation path.

What?

Download Mixtape vol. 12 – “Spot the Dog” and/or subscribe in iTunes.

Tracklist:

1. New Mjøndalen Disco Swingers – Eurodans
2. James Murphy – Going Out
3. Grasscut – The Tin Man
4. DJ Shadow – Come On Riding (Through the Cosmos)
5. Tune-Yards – Bizness
6. Jamie XX – Far Nearer
7. Diana Ross – Love Hangover
8. Billy Cobham – Heather

Update: source is available on GitHub including some basic image processing stuff.

The IOIO  is a small circuit board with a USB socket, a microcontroller and 48 input/output pins.  Plug it into an Android phone and you can use software to write to or read from each of the pins. Roughly speaking, on is 3.3V and off is 0V. Some of the pins can also function as analogue inputs and PWM outputs.

I initially looked at Arduino but in the end IOIO made more sense for a number of reasons:

• Pure Java API – no new languages to learn
• USB built in – Arduino controller would need a USB host shield to communicate with the phone
• Cheaper than Arduino + USB shield
• More IO pins than I could ever need

In theory, the IOIO board works with any Android device. In practice, there are many phones it doesn’t work with. The first phone I bought had to be returned to the shop and the second phone only worked after upgrading it to a non operator branded version of Android. On the other hand it worked straight off when I tested it with someone else’s Nexus One and HTC Desire.

Hardware

The first step was to dismantle the tank and strip out the internal RC circuit. That left only the tracks, drive motors (and gears), battery and on-off switch. Sadly that meant losing the BB gun in the turret. There’s always a next time.

Due to current draw issues, I couldn’t just connect the tank’s motors to the output pins of the IOIO. At best it would not work, at worst it could fry the circuit. I bought a TB6612FNG motor driver circuit which controls two motors using a PWM channel and two digital channels per motor. It connects directly to the battery to provide up to 1A current to each motor. I was initially worried about damage from back-EMF but so far that hasn’t been a problem.

The final pieces of equipment were a set of header pins to solder into the IOIO and TB6612 and a solderless breadboard to make it easy to reconfigure the circuit if necessary.

In the photo above:

• The black and yellow wires, centre right, are 10V and ground from the battery (via on-off switch)
• The black and red wires, top and left, go to the motors
• The blue wires are carrying 10V from the battery
• The yellow and green wire is carrying 3.3V from the IOIO to drive the TB6612 chip
• The brown wires are ground
• The TB6612 and IOIO control pins are connected through the breadboard

Software

I’m still not sure what this robot will ultimately do but an obvious first step seemed to be to make it remote controllable over the internet.

This is my first Android project but thankfully the Android SDK and documentation are outstanding. With the help of a few tutorials I went from Hello World to a simple app that accepted HTTP connections in just a few hours.

I now have a basic HTTP server on the phone which serves up a single web page and then listens for commands sent from that page over AJAX. Sending real time commands over HTTP is tricky because of the overhead in setting up TCP connections and the fact that requests may arrive out of sequence. I got around the first problem by using HTTP 1.1 persistent connections and the second by including a counter variable with each request. Any request with a counter value less than the last one received is ignored.

Using multiple threads on the phone to handle each incoming request, I’ve got response times over wifi down to around 30ms which is good enough. I’ve not yet tried it over 3G but I suspect network latency may be a big problem.

I looked into using UDP instead of TCP to send the commands as that’s what RTP uses. However there’s no way to send UDP packets from JavaScript and I didn’t want to have to use Flash or Java on the client side.

Next

Likely next steps are:

• Stream video from the camera to the browser so I can drive it from another room (or country)
• Improve the input UI to make it easier to drive
• Implement some basic machine vision algorithms such as line following or the classic photovore behaviour (drives towards light)

• Add a laser line to the front to make a budget laser rangefinder
• Let other people control it over the internet
• Use the Android text-to-speech and the phone screen to give it a voice and a face
• Hook it up to a thermal receipt printer and make it physically deliver my emails
• Implement a behaviour-based robotics API with swappable behaviours
• Foster a community of robot builders using the same API to create a pool of behaviours which can be combined to generate highly complex robot personalities
• Skynet

This passage about the equivalence, from a worker’s perspective, between new technology and free trade particularly caught my eye:

Economist David Friedman observes, for instance, that there are two ways for the United States to produce cars: they can build them in Detroit or they can grow them in Iowa. Growing them in Iowa makes use of a special technology that turns wheat into Toyotas: simply put the wheat onto ships and send them out into the Pacific ocean. The ships come back a short while later with Toyotas on them. The technology used to turn wheat into Toyotas is called ‘Japan’, but it could just as easily be a futuristic biofactory floating off the coast of Hawaii.

Jobs may be lost when new technology or cheaper imports make old production methods obsolete. But, since there can be no imports without exports, jobs are also created. On the whole everyone is better off, even if some end up having to retrain.

After clicking through 3 pages of introductory text (which nobody will ever read) the first step is to log in to the Government Gateway thing with its easily memorable 12-digit user ID. Fortunately I do my self assessment online so I already have an account because just getting a gateway login is a challenge in itself. Nevertheless I was quite impressed that they have a unified login for all government services. Or do they?

Once signed in, and after clicking through a few more screens of text, you have to enrol in the Motoring section which involves filling out all your personal details again in an extra long form which asks for increasingly irrelevant details such as UK passport number. After over ten minutes of form-filling, the last step it told me that my details didn’t match up and made me go back and check everything.

It turned out I had omitted my middle name from the form. OK, so I’ve just provided all this personal information including addresses, 16 character driver number, 10 character photocard reference number and 12 digit counterpart license reference number and they’re failing the form because the middle names don’t match? Really? After stepping through the entire form a third time because the confirmation page incorrectly formatted my postcode with an extra “0″ (incorrect use of sprintf()?), I finally completed the form.

The final step, they informed, was to print out a form, date and sign it, and post it, my photocard driving license and my counterpart license to the DVLA within 21 days.

Now pause for a moment of reflection and compare this to the pre-online experience of updating your driving license address.

Step 1: write your new address in the space provided at the bottom of your counterpart driving license.

Step 2: post this and the photocard license to the DVLA.

Step 3: oh, wait, that’s it. There is no step 3.

I intend to resume regular podcasts but to spend less time on each. Seeking out audio samples to intersperse tracks takes me ages as does sequencing and beat matching. What I mostly want is to create a record of all the tracks that have caught my attention recently so I’m afraid simple cross fades will have to do.

Download Mixtape vol. 11 – “A Few Old Tunes” and/or subscribe in iTunes.

Tracklist:

1. Hot 8 Brass Band – It’s Real
2. The Very Best – Kamphopo
3. The Bees – No Atmosphere
4. Xploding Plastix – Treat Me Mean, I Need the Reputation
5. Venetian Snares – Szerencsétlen
6. Leila – Feeling
7. Portishead – Machine Gun
8. Alhaji K. Frimpong – Kyenkyen Bi Adi Mawu
9. Tall Pony – I’m Your Boyfriend Now
10. The Doors – The End

The only way I could decipher this mess was to draw a kind of bar chart and fill in the numbers. Once I finished I realised that I had inadvertently created a hugely more readable representation of the information contained in the payslip. So here’s a copy of the original payslip and my effort at an improved version.

Click each image to expand and do spend a few minutes trying to make sense of them.

This improved version displays the same information condensed into one page while clearly showing the relationship between the figures.

Now bear in mind that I’m not an accountant, nor am I an information designer. I’m not even a graphic designer. But I am someone who receives payslips and wants to understand them. And from that point of view I hope you’ll agree it’s a vast improvement.

The principles of usability apply to more than websites & software. Just about everything can benefit form a bit of sensible design.

Currently it requires the CSV file to be uploaded online somewhere. If there’s demand I can change it to allow uploading of a file or just pasting in the data.

Convert CSV to JSON.