MCP Xander Soldaat, editor of the robot blog BotBench and author of many a driver for the C-based NXT programming language RobotC, has implemented some popular sorting algorithms in RobotC and made a nice video on visualizing their sequence on the NXT's LCD:
A nice show case for anyone interested in informatics.
Dexter Industries have updated their 'websockets' program which allows you to connect and control a robot through the Internet. This means that it'll work from a laptop, smartphone, tablet, basically anything that can load up a standard web browser. What makes it even better though is the fact that it is two way communication, mean you can send sensor values back to the web browser so you can keep tabs on your robot from anywhere in the world!
How is this possible you ask?
The hard part of using websockets is establishing a connection with a webpage. For security reasons, a key is passed back and forth in a complicated “handshake”: the webpage sends some information, and the NXT must respond with a specific answer back. We’ve taken care of that with our websockets library so you can easily and quickly setup your robot to communicate with Chrom, Internet Explorer, Mozilla, Opera, and Safari.
Dexter very helpfully supply a fully worked code example in RobotC, ready for you to tinker with.
What would I do? Set up an NXT with a temperature sensor, light sensor and sound sensor and constantly update the conditions in my office. An Ultrasonic sensor pointing at my chair could also be used to update a webpage letting people know if I'm in, or out at a meeting :)
MAKE: Magazine has just posted a great little interview with John Cole, founder of Dexter Industries.
My favourite quote from the interview:
It’s disarmingly simple: people get intimidated by technology, but LEGO’s are something everyone grew up with so it’s not that hard to start with the simple, and grow into the complex.
Congrats to John for being featured on what is probably my favourite blog!
RJ McNamara has posted a very nice description of a holonomic drive system. It uses Power Functions motors instead of the regular NXT ones and Rotocaster wheels. These wheels along with the 120 degree separation of the drive wheels allows holonomic robots to move forward, backwards as well as side to side. (They can also spin on their own axis as they travel in a straight line which is cool to watch.
What's great about this post is that he goes through the Math necessary to control the robot. He does a really good job of laying out the equations and how they need to be used to get the robot to move the way you intend.
