RayHightower.com

Thoughts about Ruby, Rails, RubyMotion, iOS, and business growth.

Manage That OpenROV Tether, Or Else

Tether management, one way that works.Tether management, one way that works. 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.

Off-the-Shelf Parts

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.

Solar Powered Parallella

Give solar power to your Parallella with a few simple components.Give solar power to your Parallella with a few simple components.

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.

ESC Programming and Calibration for OpenROV

Three ESCs, one for each motor. Each ESC has a switch and a power/signal connector.Three ESCs, one for each motor. Each ESC has a switch and a power/signal connector.

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 Assembly Challenges

OpenROV fully assembled.OpenROV fully assembled. I know this problem can be solved. I just haven’t figured it out yet, and I need help from the OpenROV community to do so.

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.

Be Awesome. Tackle Big League Problems at WindyCityRails

Be awesome.Be awesome. Do you see yourself in any of these scenarios?

  • You have already built a successful Rails app. Now that you’re “done”, you know you can make it better, but you’re not sure how. You want to take your skills to the next level.

  • You recently graduated from Dev Bootcamp, Starter League, Mobile Makers or another school. You’re ready to meet and interact with your next generation of mentors.

  • You are no longer a beginner. You have seen advanced developers in action, and you are determined to get there yourself.

  • Software development is relatively new to you, and you built a successful track record in another profession. You want to meet people who can help you accelerate through the beginner phase so you can launch something useful.

Common thread: It’s time to unleash the awesomeness in your bones. You want to take your skills to the next level, and you are ready to tackle Big League Problems. WindyCityRails is for you.

Wanted: Community Manager

Jamming together. Growing together.Jamming together. Growing together. WisdomGroup is hiring a Community Manager (CM) to help run our user groups and conferences. This is a part-time independent contractor position, mostly remote, with some on-site work during meetings and conferences. The position could become full-time depending on results produced and community growth.

Smart People, Growing Together

Our community philosophy:

When smart people challenge each other to grow, great things happen.

Our community track record is covered in the article How to Grow a User Group.

LinuxBarbados is Global

LinuxBarbados is a user group for open source enthusiasts. The group meets monthly, offering solid knowledge for anyone who wants to ramp up their open source skills. For example, yesterday’s meeting featured a presentation on XBMC by Michael Layne. The presenter dug deep into the tool, offering tips on how to write plugins in C++ or Python.

RVM and Parallella: What a Difference a Shell Makes

RVM is an effective way to manage Ruby versions on Linux or OS X. RVM was working well on my Ubuntu-based Parallella, until one day it stopped:

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linaro-nano:~> rvm list
rvm: Command not found.
linaro-nano:~>

rvm: Command not found. Fortunately, Zach Briggs and I were pairing at a joint OpenHack – ChicagoRuby event when the problem occurred. Zach is an ideal pairing partner; troubleshooting was smooth because he was there. Time to investigate.