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A robot car kit to satisfy curiosity

A robot car kit to satisfy curiosity

Ever since our little ones got hooked on watching NASA/JPL Curiosity landing videos, they’ve developed a strong interest in robotics (yay!!!).

And as luck would have it, our kids would often ask me (the dad) to “build a robot”.  When the kids were younger, building models with LEGO would suffice.  But it soon became apparent they wanted a “real” machine.  I had given a design try a while back.  I spent a few evenings looking up design ideas, drafting up sketches of mechanical pieces that we could fab from hobby plywood… but never got further from the computer screen.

Historically, I haven’t been a huge fan of turnkey kits.  I had saw them to be either of low quality or charged a significant premium for the convenience of all pre-selected parts in one box.

But then I found this Elegoo Smart Robot Car Kit on Amazon: https://amzn.to/2zESV0V

The kit comes with an Arduino control board, an I/O board, a ultrasonic module, a bluetooth module, line following module, motors, wheels, chassis, and all hardware needed for assembling the kit.

 

My Value Justification:

At time of writing, this off-the-shelf kit will get to your door for $69.99 USD.  You can easily spend half that cost just on machining the chassis plates yourself.  You could alternatively individually purchase a standard Arduino board, and other modules, but you’d still have to figure how to mechanically and electrically link them together.  The board designs may be open source and be a good EDA design exercise, but good luck getting the PCBs made for < $100 before you even add in the parts BOM.

The Build:

It went really well.  The kit came with clear illustrated instructions which our 2nd grader and Kindergartner were able to follow along with just a little hand dexterity help from me for some of the tighter screw assemblies and finer connections.

Parts quality is good.  The pieces appear to be machined well.  The components and hardware aligned up very easily with little fuss.

The kids now have a robot:

The kit includes demo and learning firmware projects to load via the Arduino IDE.  We are able to upload the “auto_go” firmware to the kit and watch the car drive around on the floor.

I’m quite impressed at this kit, what it comes with, and what it enables.  The car robot as-kitted presents many learning applications, but it also lends itself to expansion and modding.

In terms of inspiring learning pursuits, robotics engages the young hungry minds in mechanical engineering, electronics design, embedded firmware development, and applications development.

 

 

Introducing Computer Science with micro:bIt

Introducing Computer Science with micro:bIt

Throughout the school year we introduce computer science concepts as appropriate for age and skill level.  Towards the end of last school year we started using the micro:bit platform as a fun learning tool with much success and plan to continue in the following weeks.

The micro:bit (available at https://amzn.to/2MoWJKJ) is a plug-and-go easy to use introductory electronics and programming platform with a 5×5 LED “display” matrix, a couple buttons, and a 3-axis accelerometer.

The kit comes with a battery pack and a short micro-USB cable for power/programming.  The longer hi-visibility red cable that I used is this one: https://amzn.to/2KQv6Wm

The programming environment is web based, so any computer with a modern browser and an available USB port should work.  Our kids were able to do the labs with our relatively low-power, long battery life Samsung Chromebook 3: https://amzn.to/2nDF83M

 

 

Time-Lapse capture with webcam and Linux scripting.

Time-Lapse capture with webcam and Linux scripting.

Time-lapse photography is a concept of taking snapshots at a particular interval over time to record events in a low resource manner, compared to capturing a video stream.  Here, we discuss how to use a relatively inexpensive web camera and a computer to build a low-budget time-lapse platform.

Action Summary

Video capture of a video capture

Pretty much any relatively modern PC with decent storage and functional USB 2.0 ports should suffice.  I had an old big-box special on hand.

Logitech webcams tend to plug-and-play easily with Linux distros: https://amzn.to/2vr2H4c

The Logitech C615 is the model featured.  It does 1080p capture, with some nudging.

*Even though I held up an external HDD in the footage, I didn’t get to show setting that up yet and instead relying on internal storage for now.

The “cheese” program is a quick way to test a webcam. (https://help.gnome.org/users/cheese/stable/introduction.html.en).  To install on a Ubuntu/Mint system, use apt-get in a terminal window:

sudo apt-get install cheese

Multi-adjustable Gorilla Pod Tripod makes for camera positioning in tight corners.  Mine came as a kit with a flashlight, but here’s a standalone model: https://amzn.to/2nlG5O7

We looked at how to use the fswebcam Command Line utility to capture images via the terminal.  You may either git clone from the project page, or on an Ubuntu/Mint system, enter in a terminal window:

sudo apt-get install fswebcam

It is a bit of trial-and-error figuring the optimal parameters for the fswebcam utility with a camera.

Then we watched how bad I am at live shell scripting, though I freely admit its not my everyday gig and that I make liberal use of internet search the few times I write shell scripts.  Can’t go wrong with an O’Reilly book on Shell Scripting if you want an at arms reach reference to thumb through: https://amzn.to/2Onqol0

 

Hope you found this useful and informative.  Having a setup like this opens up a lot of other potential applications to build upon.

 

Disclaimer: from a technical and functional perspective, this post is about using extending usage of commodity hardware using computer scripting.  There are some potential premise security applications for such a setup.  While anyone is welcome to use the information herein, the reader is responsible for determine appropriate for use, deployment, and maintenance of such applications for their security needs.  I/We do not explicitly endorse this type of setup as a part of a security protocol.

 

Getting Started: A Hi-Value, Low-Budget Laptop Option

Getting Started: A Hi-Value, Low-Budget Laptop Option

Forward: For anything that ever gets posted on this site as a tutorial or project series that calls out materials and/or tools that are not free to follow along on your own, please assess your continued personal interest in the subject matter before committing to a purchase, especially if the considered item is more specialized than general purpose.  Feel free to continue reading the posted materials to gauge interest.

That being said, a computer has many uses by many people.  If you were to buy a computer to check out programming tutorials online, it could just as well be used for many other non-programming tasks.

Now, if you already have a capable computer that you have full ownership or authorization for use/configuration, just use that.  The best things are those that you already have.

So, doesn’t that include everyone?  This is 2016, not 1996.  Well, not quite: Even though affordability has improved vastly over the years, it can still be a stretch to obtain a computer.  But even for those who are more than able to afford a computer, with many personal computing needs being met with smartphones and tablets, a lot of folks can forgo a computer in the home.

That is, until you want do things outside of email, “liking” your friends, and taking selfies with food.

Computers of the desktop and laptop variants are on the market at many price points and feature-sets, and I am to believe folks are more than capable of finding one that best fits their needs.  Any attempt of writing out a buying-guide would be wasted efforts on my part, as many review sites already fill that role.

But I’ll focus on “hi-value, low-cost” for a moment.  If someone who didn’t already own a computer (and access to a work provided machine doesn’t count…), I would suggest spending the least possible if their only driving interest in owning a computer is to follow along posted examples on my site.  But I’d still want to propose a system that’s decently built with reasonable specifications.

Enter: The Chromebook.

Screenshot - 07182016 - 10:14:56 PM

A category of low-cost (except for the Chromebook Pixel) hardware running Google’s Chrome OS, plenty for most casual computer users, many models with battery specs that rival that of big-box door-buster traditional laptop models.  Base system storage is eMMC, and while typically relatively small (16, sometimes 32GB), is usually augmented by an available SD/microSD card slot, thereby presenting a fully solid-state system.  Most Chromebooks are equipped with 2 USB slots, and some form of video output (e.g. HDMI).

Browsing available models, thin and light is a common theme, making them pack and go anywhere.

Chromebook (and ChromeOS) is commonly positioned as an internet-reliant thin-client of sorts: It’s easy to summarize the intent of a Chromebook as a Chrome Browser as a computer system, with “applications” in the form of Chrome Apps and Extensions.  –and for email, general browsing, office productivity (via Google Docs), VOIP (Hangouts), and light photo editing, its quite a sufficient setup.

However, by following some well documented steps, a Chromebook can be easily enabled as a stealth economy Ultrabook alternative:

Screenshot 2016-07-18 at 8.17.56 AM

Yes, I am a recently new owner of a Chromebook that runs an Ubuntu Linux system within a window.  Running Linux opens access to all software (within CPU and storage reasons) on the Linux platform to my $200 econo-laptop that seems to have no problem returning 11 hours unplugged life under more pedestrian uses.

I further detail what I did to get the screen capture above in this HowTo, but in summary it was:

  1. Unbox and verify machine works out of the box.  Allow system to update.
  2. Backup The System, just in case…
  3. Enable Developer Mode
  4. Use Crouton to automagically download and install Linux in a chroot.

Tip: Using a large SD card split between “local storage” and “Linux” helps keep the limited eMMC block dedicated for ChromeOS.

New-purchase prices for Chromebooks tend to range between just below $100 to maybe $400 on the higher end, with the Pixel on the other side of $1k.  In the 2-3 US Benjamins section, distinguishing specs are screen size, CPU type, and RAM.  Look for:

  • Screen size: 11.6″ is great for ultra portability, 14″ or 15″ can be had with 1080p resolution.
  • Small convertible models are nice if you want to stay on from gate to gate while flying domestically in the US.
  • I’d strongly recommend an Intel based CPU (e.g. Celeron).  ARM is fine for ChromeOS, but may present some hurdles with Linux applications since most are written for x86.
  • Strong preference for fanless design.  One less thing to fail or draw milliwatts from the battery, and less concern for internal dust accumulation.
  • More RAM is better if available.  For most models, its not user up-gradable so you’ll have to choose when you buy.
  • Larger eMMC is nice-to-have, but ChromeOS itself keeps a small footprint on its own.  Make sure your model is equipped with a SD or microSD card slot.

The system I’m staging as a sample software development platform (and using to update this page…) was obtained for $200.  It comes with a matte, anti-glare 11.6″ screen, 4GB RAM, 11hrs quoted battery life and has a $40 128GB microSD card loaded.

A value that’s pretty hard to beat for a tad under $250.

Happy Computing!

Further Reading: