Long-time observers of ChicagoRuby know that the group is always striving to achieve more. Latest move: ChicagoRuby is now hosting a monthly meetup on Chicago’s North Shore. The first meeting of ChicagoRuby: North Shore will be held on Saturday, December 6, 2014 at 10:30am. Visit Meetup.com for details and to RSVP.
Geekfest is a weekly event hosted by Groupon’s engineering team. Every Tuesday at lunchtime, the company invites members of the tech community to present topics that are interesting to a technical audience.
I wish to express my thanks to Groupon for inviting me to present OpenROV at today’s Geekfest.
Members of the University of the West Indies (UWI) Computer Science Club and LinuxBarbados just finished a joint session this afternoon. I am grateful that the group invited me to present. Outline (prepared in advance):
30 minutes: Overview of Ruby, Rails, and some alternatives to both. What are the advantages and disadvantages of building web apps with Ruby? Can you build a business with this stuff?
30 minutes: Questions and Answers. This will be a highly interactive time. Anything discussed earlier is fair game. We can explore technical specifics if you like.
60 minutes: Deep dive into anything the group wants to explore related to technology, business, or the combination of the two. If the group doesn’t choose a topic, we will end early. But if the group is interested and engaged, we will continue.
RubyCaribe (pronounced ka-REEB) is a conference for intermediate and advanced software developers who use Ruby. The conference will be held January 27 – 31, 2015 in Barbados. January is a beautiful time to visit the Caribbean, especially if you’re coming from a colder part of the planet.
Intermediate and advanced software developers will find RubyCaribe valuable because…
- Each RubyCaribe session features a 30- to 45-minute presentation followed by a 2-hour deep-dive lab. Learning is reinforced throughout.
- The venue, Hilton Barbados Resort, sits right on the ocean. Need a stretch break? Take a walk on the beach!
Note: This article has been updated with more photos and details describing slip ring installation.
Youthful exuberance drove me to pilot my OpenROV before I built a good tether management system. Bad idea! It’s better to have a tether management plan (any plan) before you pilot your OpenROV.
This article describes a tether management system that works for me. Other OpenROVers have devices that work, too. Take a look at a few and eventually you will find one that fits you.
This tether management system is constructed entirely from off-the-shelf parts. The main component is an extension cord reel sold by Home Depot for about $14.00. Buy it, gut it, add the slip ring using three screws (also from Home Depot) and you’re good to go.
This article describes a simple hardware hack: Making the Parallella run on solar energy.
Motivation: The fastest computers in the world gulp electricity at an alarming rate. For example, Tianhe-2 at the National Super Computer Center in Guangzhou, China uses 17.8 megawatts of energy per year. In dollars, that’s roughly $17 million spent on electricity spent each year, depending on how the electricity is sourced.
Scientists at Sandia National Laboratories estimate that the earth’s surface absorbs enough solar energy in ninety minutes to power every electrical device on the planet for a full year. A year’s worth of energy in ninety minutes! Surely we can use some of that energy to power our supercomputers.
OpenROV #1227 went for a spin in Lake Michigan this week. Success! Here are a few first-voyage observations:
ESCs: New Experience for Me
Electronic speed controllers (ESCs) were completely new to me when I first assembled my OpenROV. This article documents my initial misunderstanding (and eventual understanding) of ESCs so that future builders can move forward with fewer glitches.
OpenROV community to do so.I know this problem can be solved. I just haven’t figured it out yet, and I need help from the
Update: The OpenROV community delivered. Solution: ESC Programming and Calibration for OpenROV.
Parts That Work
Software image updates on the Beaglebone Black work flawlessly thanks to scripts written by Brian Adams and Dominick Fretz. The cockpit software shows a real-time image from the camera, the LED lights are super-bright, and the lasers hold steady at 10cm apart. My fully assembled OpenROV passes the water submersion test. Yes, it’s waterproof, thanks to O-rings and silicon-based lubricant!
What about the motors? The motors work, almost. Could it be the electronic speed control (ESC) settings, calibration, or less than perfect soldering? That’s where I need help.