Controlling a toy car in a race track using an Arduino and a sonar

I thought about creating different ways to control a toy car in a race track, instead of the typical handheld joystick-like device. One of those ideas was based on the use of a sonar (that measures distance to an object) as the controller for the car – the closer the hand to the sonar, the highest the acceleration.

arduino_sonar_race_track

However, considering that the sonar works through eco-location and that the track makes an infernal sound, the sonar accuracy is affected by the sound of the track, thus rendering this approach useless.

Any alternative ideas? I will try the best one (as long as it is not cost-prohibitive) :)

Spinning paintings

When I was a kid, I used to do these spinning paintings using a small motor (salvaged from a broken toy car) connected a 9V battery with a piece of paper on top. The effect was mesmerizing and I had fun for hours.

Last week, given the amount of hardware I gutted for parts (for a digital fabrication workshop), I ended up with a bunch of different motors and that brought back those memories. So, I decided to do the same setup again, this time using an arduino (to easily control the speed given to the motor) to see if my son would find it as amusing as I did.

Check the video for a demo:

My son loved it … and so did I :) Here’s the setup:

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And an interesting result:

2013-07-16 11.26.19

R.I.P. Google Reader

And so an era ends.

RIP Google Reader

I’ve been using Feedly as an alternative because the mobile apps are quite good and the website is a “prettier” google reader. And they actually listen to the users and implement requested features. Also, it seems my Mac RSS app of choice, Reeder, will soon have support for it, so I probably won’t miss Google Reader that much.

The only winning move is not to play

What happens when you leave 16 autonomous AI bots alone to play Quake 3 Arena against each other for 4 years? Apparently, they play the ultimate Cold War game and achieve “world peace”.

I don’t know if this story is true or not, but it actually makes sense from a purely logical self-preservation point of view. The bots were programmed to study which strategies were more efficient in guaranteeing their survival. After a few years, they probably realized that the best strategy is actually to not engage each other and they all win.

Check the story thread’s screenshot here.

(Seen here via @sh4na)

Learn how differential steering works

I’ve never actually been that much into cars but I have a general curiosity on how most things work and this includes the inner workings of vehicles. This golden-oldie video depicts the simple, yet effective, mechanism of differential steering, so if, like me, you didn’t know how this worked…well, now you know. Enjoy:

(thanks, Sérgio)

What I’ve been reading, Vol. VIII

Christopher Priest – The Prestige

My Review: The jury is still out on my favorite Chris Nolan movie, but The Prestige is definitely up there fighting for first place with Memento. So, it was no surprise that I felt I had to read the book that originated the movie. The book is quite different from the movie but the rivalry between the two performers is still the baseline of the plot. However, the storyline is presented by way of the performers’ grandsons reading their personal diaries, entry by entry and trying to make sense of the long-standing war between their families. I very much enjoyed the book as it presents a quite different story based on the same premise, but the delivery is not as good as in the movie. Nevertheless, it’s still a great read for fans of the movie.

My Rating: 4/5

Terry Pratchett, Stephen Baxter – The Long Earth

My Review: Imagine that there are multiple (possibly infinite) parallel earths that you can visit (“step”) using a very simple potato-powered device that you can build with rudimentary components. This is what this book is all about: setting the baseline for this kind of universe and how this affects society. The story then revolves around a small set of characters that step all over several different Earths in an attempt to understand and discover everything there is to know about this phenomenon. The idea behind the book is great and it definitely raises some interesting questions but the fact that this is only the first volume of a planned series is evident in the pace and continuity of the plot. I’ll look forward for the next volumes.

My Rating: 4/5

Max Brooks – World War Z: An Oral History of the Zombie War

My Review: This book focus on a fake documentary that gathers witnesses’ reports from all around the world regarding the (fictional) Zombie War. It has the same problem as Robopocalypse: in stories based on characters reporting what happened, you already know that those characters didn’t die. And that kind of spoils the story on so many levels. Nevertheless, you still have some interesting twists that can save those story-telling chapters, but that doesn’t always happen and most stories are boring. I think the upcoming movie based on the book may have taken the right approach by focusing on a single character’s point of view (Brad Pitt) and therefore bringing in only the most exciting parts of the book.

My Rating: 3/5

by J.R.R. Tolkien – The Hobbit

My Review: There isn’t much I can say about this book as it is a well-known piece of literature. I quite enjoyed reading it but it would have had a much greater impact on me if I had read it at an earlier age. The Hobbit is definitely a more fantasy/adventure story directed to younger audiences than, say, The Lord of the Rings’ books, which is a lot darker and more dramatic in the fight of good versus evil.

My Rating: 4/5

George R. R. Martin – A Storm of Swords (A Song of Ice and Fire #3)

My Review: It’s pointless to try and say much about this book without shooting spoilers all around, so I’ll just say this: two thirds in on this book and I was ready to give it a 3/5 rating, mainly because almost all of the characters spend most of their time traveling and not much happens in terms of the initial development present in the first two books. However (and I can’t stress this “however” enough), the last third of the book is priceless. Huge turns, twists and developments make up for the rest of the book and leave you hanging for more developments (which I hope will be address in the next book).

My Rating: 5/5

Related: What I’ve been reading, Vol. I, IIIII, IVV, VI and VII

Modern-day Twilight Zone

Imagine that the typical money-for-ransom is traded with a weird request like: “If you want to get your dear princess back, the prime-minister will have to have sexual intercourse with a pig on live television.” Will the prime-minister do it? Or more importantly, in a heavily socialized society where viral content dominates the people’s attention span, would they want him to do it and would they watch?

Or imagine that you live in a future where the most common way of making an income is to work on huge energy-production buildings where people pedal specialized stationary bikes to produce the energy that the rest of the world will consume. The alternative of leading this boring and tiresome life is to become a star in worldwide-broadcast reality shows that range from singing or pornography to physical abuse. Is everything better than the bike?

Or imagine instead that everyone has a brain implant that allows recording and reviewing every memory they have ever had and, by using a small external device, people can simply rewind and fast-forward to a particular memory and display it on a nearby TV for everyone to see. Now imagine you suspect your wife is cheating on you and you over-analyse every memory that you have of her with the guy you suspect she’s having the affair with. How long would it take you to go insane?

BlackMirrorTitleCard

(Image source)

These stories are the plots of the 3 episodes of the first season of BBC’s wonderful series Black Mirror, a techno-paranoia drama where each episode features a different story, a different cast and a different reality. In a modern-day Twilight Zone-like setting, each story brings us a potential future for our society that, albeit seeming a bit extremist, will definitely leave you thinking if this is really what you want for your future.

I definitely recommend everyone to see it. I dare say it’s mandatory for anyone with any kind of technology enthusiastic view of the society.