On April 6th, I premiered a new bot at the Southern Maine Gearbots District Meet! Lunar Land3r, is a new EV3 take a retro video game. Here is a quick (3 second) timelapse of setting up the bot shot on my new GoPro. The full video will be coming soon. Stay tuned!

Video  —  Posted: April 9, 2014 in Engineering, LEGO, News
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Arduino 101 Class

Posted: February 22, 2014 in News

WP_20140222_002As some of you may know, I have been spending some time at the Gainesville Hackerspace lately. Much of it has been dedicated to work for the Gator Amateur Radio Club roof project, but I have also gotten involved in a few other things. One of those ‘things’ is teaching an Arduino 101 class. There seemed to be significant interest in Arduino, but little experience. I taught a class that focused on the basics: digital I/O and analog I/O. The class ran for 2 hours and it was very a success! We had 9 people in this first class and everyone seemed to walk away ready to start a new project. There have been requests to teach the class again for people who were unable to attend, as well as teach a slightly more advanced class, Arduino 110, that goes more into UART, I2C, and other standard, but more complex features.

I have posted the class material to the downloads page. However the files are encrypted (for now). I may open them up in the future, but I would like them to go through a few more revisions so that I am not having to support all the various revisions. If you’re in Gainesville and want to learn more, head on over to their website and get involved. They have open houses every Tuesday night.

 

So a few weeks ago I got a VEX IQ set. I have been working on mobile robotic arm. This video showcases the drive base for the robot. I have it working via remote. All the software is written in RobotC. This is just step 1, the arm will be the next challenge, but just wanted to share what I have been doing!

You can learn more about VEX IQ here and join the discussion forum!

Video  —  Posted: January 21, 2014 in Engineering, News, Robotics
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As many of you know, I am a ham (my callsign is KK4LWR), or amateur radio operator. Over the holidays I ventured home (to very cold Ohio) and worked on a cool project with my brother, Tony. Tony, KD8RTT, and myself took a cheap CB whip and cut it down for mobile operation on the 10 meters band. The process was pretty simple and if you’re a new ham, it is a good, cheap way to get on the air. This hack is also a good introduction to using an antenna tuner and the importance of a standing wave ratio (SWR).

Check out the original post on my brother’s blog.

Video  —  Posted: January 19, 2014 in Amateur Radio
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Many of the people that follow my blog know I do a lot of robotics. I build robots, I write software for robots, and I mentor/coach FIRST teams. If you know anything about FIRST Robotics Competition (FRC), you know January and February are busy months. This is the build season. Between my research and mentoring a team, I have almost no free time. I do have a few projects that need to be posted and I will try and get to them as soon as I can. I have some updates on my Glow with the Show ears, APRS on a Beaglebone, NXT Simulink Tutorial, and VEX IQ.

In case you were wondering what this year’s FRC game is, see below!

7200OTAnother trip, another book (and a bonus deal)! Remember that Maker Faire Demo and all that image processing? I relied heavily on the Image Processing Toolbox in MATLAB and I thought I would share a good resource I came across.

Visual Media Processing Using MATLAB by George Siogkas is a good introduction to the Image Processing Toolbox. It starts with a brief overview of the MATLAB UI and then digs right into opening and displaying images. The book goes a good job of presenting processing logic and then code to execute that logic. I was able to quickly follow along and execute the same commands. After Siogkas does a few commands, he looks back at the code with a really helpful section called “What just happened?”. These sections are very helpful as they provide a different look at the code you just executed. I have found myself referring to these section and the preceding examples over and over. Each chapter contains several subtopics, so having these review sections is a good way to break things up and ensure you know what you’re doing. Also these sections tend to have big, bold headings, making it easy to find glancing though the book. (Which is more common for me while working on a project.)

The book is sort of a cross between a textbook and tutorial. Each chapter ends with a review quiz, but unlike textbook, this is not designed to be a drawn out homework assignment. Also unlike a textbook, the author takes on a more tutorial tone with very well thought out examples in which he guides you though each step. Like a textbook though, each chapter ends with a listed summary of point covered. I generally find summary sections to be sort of vague, but if it helps you, it is there. (The author lists things accomplished like “How to create …”, “How to isolate and expand …”)

Overall I really liked the book. It is a great reference and a good way to get start in MATLAB. You can find it on amazon or though the publisher. Speaking of which, that bonus deal I mentioned… Packet Publishing is having a holiday sale. You can click the banner below or follow this link. The deal is $5 for any ebook or video from packet now (December 19th) though January 3rd. A few of the books I have review come from Packet, so it might be a good way to pick up some books for the new year on the cheap!

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Remember that Maker Faire demo I posted about a few weeks ago? Well as promised here is Part 2! This time I dive into the new features I added for the demo. The video format is a bit strange in that it presents a PowerPoint, but that was a requirement for a class. I ended up leveraging this work for my image processing class this semester.

One of the easiest ways to make a demo interactive is to kid a child a maker and say draw. That is exactly what this demo does. As the child draws, the robot or swarm will follow the line. I do some image processing to find the line. The first step is to reduce the search area. This is a huge time saver when it comes to processing and removes many of the issues of shadows or various markers and body parts the camera may see. Then it does a search in this region of interest (ROI) and looks for where the line intersects the ROI.

I tried to keep the new feature as streamlined as possible to avoid the issues of degraded performance. Image processing can be quite processor intensive. Since the code was already doing a lot of processing to get to this point, I wanted to ensure that any further enhancements did not add lag.

There is always room for improvement and one of those areas would be actually projecting the line to calculate the intersection. This would probably help for the cases where the line does not intersect the edge of the ROI, but that is a feature for another time. Check out the video for more details. It came together really well!

Video  —  Posted: December 11, 2013 in Engineering, LEGO, MathWorks, News, Robotics
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