Cheap Ball Casters for Small Robots

Hello everyone! :) In the title of this blog I mention that it is also about robotics. However, and to be honest, I've realized that I haven't posted much stuff about it. I hope to fix that in the following posts since recently I've finally finished some robot projects that I have been doing in the past months. Unfortunately I can't publish them yet. Maybe in a month or two :) Anyway, I'll start with a simple post regarding a simple but very useful part for small robots: ball casters!

You can buy ball casters from several robotics shops online and they're not the most expensive thing on earth. However, there are other options that can be cheaper and will save you from the waiting until you receive the ball casters that you may order from shops online. Some of the options fit in the spirit of Green Robotics, which is the idea of reusing and recycling everyday things to make robots. I'm going to show you three options that may suit your needs :) .

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I'll start with the option that I think to be the best of the three that I'm going to talk about. See the shiny metal balls stuck in a white plastic piece? They look really good, don't they? :)

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How to Install LibreOffice 4.0 in Ubuntu 12.04

Hi there! I don't know if you've heard about it but this week we had some great news for the open source community and Linux: LibreOffice 4.0 has just been released. :) I'm not going to describe all the new features and improvements since you'll get a better glance at them by visiting the release notes. I'll just point out four of them which I think to be the most significant:

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1. Better interoperability - Interoperability with other file formats is a very important feature for any user and a critical one for enterprise users;
2. Remote control Android app for presentations - a month ago I was just discussing with my brother how this would be cool to do and gladly the LibreOffice development team made it a reality. Now you can control and view the presentations simultaneously in your Android phone or tablet;
3. Preetier User Interface - it now supports Firefox Themes. Now you can customize the looks of your Libreoffice instalation;
4. Better Performance - faster, faster and... did I already say faster?

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The Bit Bang Theory's Portuguese twin brother: Teoria do Bit Bang

Hi! I have some good news about this blog! :) Probably you've noticed the little Portuguese flags at the beginning and at the end of each post. Well, they're direct links for The Bit Bang Theory blog's Portuguese twin brother: Teoria do Bit Bang :) .

When I started this blog I decided to write in english for several reasons:

1. We no longer live in our street, village, city, country, etc. We live in a global world. With the evolution of Internet we now have access to things made on the other side of the world in a matter fo seconds;
2. English is the universal language;
3. Portugal is a really small country and I thought that the number of readers would be rather small;
4. Most of the Portuguese people that are interested in the things written in this blog understand English pretty well.

However, after one year and a few months of blogging, after creating a Hackerspace with some friends, after knowing some more people with the same interests and after seeing that Portuguese people are the #2 readers of this blog (being people from the United States of America the #1) I decided to create a twin brother for this blog and embrace some new objectives:

1. Provide technical information regarding robotics, electronics, computer science, etc. to Portuguese readers;
2. Show some people that technical stuff doesn't happen only in universities and big companies, it can happen at home too, and it can happen here, in Portugal;
3. Motivate others with the same interests to get into electronics, robotics, mechatronics, computer science, etc..

So, if you're Portuguese, from now on you can read this blog in your mother language :) If you're not, you can still read it in English. I hope this to be a good decision and a big step forward for this blog :) . 

Take care!

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Turning the Raspberry Pi into a Wireless Access Point

Hi! Following my latest posts on how to get started with the Raspberry Pi "headless mode" and Using Bluetooth with the Raspberry Pi now I'll show how to turn the Raspberry Pi into a Wireless Access Point. Most of this post follows what is described here but I added a few more steps. Moreover, I ran into some troubles and had to do some troubleshooting. I used a D-Link DWA-140 Rangebooster N Adapter which contains a Ralink RT2870 chipset.

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 The process looks a little long but it can be done in under 10 minutes :) . Every time you need to edit or create some file (for example /etc/udhcpd.conf) among this process you can use "sudo nano /etc/udhcpd.conf".

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Installing Bluetooth tools in Raspberry Pi

Hi there!

Following my previous post on how to get started with the Raspberry Pi "headless mode" I'll now show you how to install the Bluetooth tools.

On the project that I'm working on right now I'll be using Bluetooth with the Raspberry Pi so that later I can connect to several devices via Bluetooth. For this purpose I have ordered some USB Bluetooth dongles from ebay and some HC-05 Bluetooth modules, also from ebay.

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The first thing to do is type "lsusb" in the terminal to see if your USB Bluetooth dongle is being recognized. As an example, the ones I ordered from ebay show up as:

Bus 001 Device 004: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)

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