Beaglebone Black and Ubuntu – Copying the OS Image to the SD Card from Linux

beagleAbout a month ago (maybe longer), I started my Beaglebone Black saga and in one of my first posts, I recall mentioning that I was unable to copy the OS image to the SD Card in Linux.  My process was to format the card, then boot into Windows and use ImageWriter for Windows to copy the image to the card.  Then move back over to Linux to carry on.  Yesterday, while I was waiting for FFMPEG to compile (foreshadowing), I was be-bopping around on’s web site and read a paragraph about the Mac process for copying the image to the sdcard.  I had previously skipped that since I wasn’t using a Mac.

So, after some careful experimentation, I was able to get the copy to work on Ubuntu.  Here’s how I did it:

First, check to see what the device designation is:

sudo fdisk -l

for me it was /dev/mmcblk0

Next, for convenience, I changed directories to my Downloads folder where I unpacked the gzip’d version of my OS image.

Finally, I entered in the following command:

Before doing this, be aware that this command, if not carefully used, could quickly and easily destroy your host system.  Just pretend that you are on the ledge of a very, very tall building without a railing.  Scary?  You bit it is!

sudo dd if=ubuntu-raring-13.04-armhf-3.8.13-bone20.img of=/dev/mmcblk0

The article included an additional parameter, “bs=1m” but Ubuntu did not like it so I took it out.  I can only assume it is a Mac-related thing.

Anyway, after entering this command, I waited about 20-30 minutes.  When the prompt came back, I pulled out the card, slipped it into my BBB and viola… A new, sexy install of Ubuntu was on my card, waiting for glorious projects.

Here’s the original article (the code is near the bottom):

PS.  Yes, Be-bopping is an industry term.  Don’t believe me?  Look it up…

Workbench-Nearing Completion

03534 ATonight, I made a push to finish the workbench but things happen and I wasn’t able to put the bow on it.  However, I did get a lot done.

We left off with the untrimmed legs laying on the workbench surface waiting to be mated to the tabletop.  I began by assigning each leg to a corner then marking of the center of where the leg would be from the outside rail of the frame.  The plan was to secure the leg to the table top with a hex bolt. I didn’t get very far when I was interrupted and had to assume other duties.  While otherwise occupied (probably doing the dishes or folding laundry… some household chore), I started thinking about stability.  If I only use one hex bolt, over time, that will become an axle for the legs to pivot on.  Not good.  I rushed to my nearest big box hardware

Where we left off

Where we left off

store and picked up four more hex bolts, eight lock-washers, and 8 locking nuts.

The next day I measured out (from my center marks) the center for each bolt.  Once satisfied, I used my 1/2″ auger bit to drill out the holes.  I had a little trouble with this in that my 7.2V DeWalt and 12V Ryobi cordless drills didn’t have enough juice to get the job done.  I was afraid that they just didn’t have the muscle.  I did as much as I could then when the batteries gave up the ghost, I switch to cutting the legs to size.  Since I want the bench to be 36″ tall, I cut the legs to 34 1/2″ (tabletop is 1 1/2″ thick”).  This is cake using a miter/chop saw.  But it’s 11:30PM and I have children sleeping so this would have invoked an ass-beating of epic scale.  Since I want my wife’s encouragement and support, I opted for the hand saw.

wb-06-outside-leg-attachmentI really haven’t used a handsaw where it counts.  I’ve used them in the past to cut stuff up but not with the level of precision that I “needed” from the miter saw.  I found out, like with everything, practice is important.  My cuts on the leg are not square and just off.  Since its on the end grain, the plane doesn’t want any part in that.  I will need to use my palm sander to get this fixed.  Learning is living, aye?

The next day, I had fully charged batteries and a new attitude.  This bench was going down (or up?)!  I finished up drilling the holes into the rails (Yay! The drills still have some life left) and then marked each leg’s bolt hole location and then drilled all the legs separately.  I thought this was going to give me trouble because I can measure twice or a hundred times and still jack up a simple hole.  Well, I can tell you that I did NOT this time.  However, there were some minor variations in the alignment.  I think this is good since it helped lock in the legs once the bolts were fastened.

Now that the legs are drilled, I began by attaching the bolt closest to the tabletop firstwb-05-ahh-nuts then moving the the upper (lower? … the table is upside down at this point) bolt.  The first bolt is much easier then the second and I discovered how far my drill holes were off.  I didn’t have to alter any holes but I did have to use my BF Hammer to get some of them in.  Once I locked the first leg down, I pushed and pulled on it to see how stable it really was… <insert evil laugh>  It was gloriously solid and whatever stability issues I might have, it won’t be due to wobbly leg joints.

wb-08-wiggle-testI proceeded to attached the other three  legs and then went around and gave each bolt a final snugging up.  I still have to install the braces on the legs but I wanted to see the workbench on it’s feet.  I flipped it over and set it up (this was not the easiest one-man job).  I was surprised at how high it was.  Yup.  36″ is pretty high.  I also needed to see if it was going to be stable.  Meh!  This workbench design has a basic flaw in that it is long, narrow and tall.  If I chopped 10 inches off the legs, that would probably help but that means it’s back to the crinkle-back, all hunched over my work.  I want it this height.  The other thought would be that I could add one or two more 2x10s and widen it.  I think this would allow me to keep the height and give me more stability.  Space is limited so I am going to stick with this design for now and try the leg braces.  I can do my planing on the ends of the table which will prevent the tippiness.  Since I attached the legs to the long rails of the frame, I can simply pull out the short rails and put in longer ones.  I will have to do some serious disassembly but it’s something I could finish in an afternoon.  Something to consider.

wb-10-workbench-functionalSo, I threw my shooting board on the bench and started planing a scrap piece of wood.  I definitely need to work from the ends when doing planing or chisling (where permitted).  It’s a little wobbly but I still haven’t attached the braces or flattened out the feet.  I am planning to surface the feet with bicycle tire tread (I saw this done while making a dog sled on “How It’s Made” on the Science Channel).  Once flat, the tread should give a solid non-slip surface to keep the bench from sliding.  I don’t want to permanently mount the workbench to the floor.

Tomorrow night, I plan to add the leg braces then flatten and surface the feet.  If I have time, I will start planing the surface and get the MDF for top.

Oh, I almost forgot.  I had to make some alterations to the dimensions.  Here is the cut list.  Keep in mind the following:

  • 2×10 = 1 1/2″ x 9
  • 2×4   = 1 1/2″ x 3 1/2″
  • 1×4   = 3/4″ x 3 1/2″

Cut list:

  • (3) 2x10x54 (table top)
  • (2) 2x4x50 (long rails)
  • (3) 2x4x20 3/4″ (short rails and center brace)
  • (8) 2x4x34 1/2″ (legs 2 laminated together to make a 3×3 1/2 post)
  • (1) 1x4x51 1/2″ (long leg brace)
  • (2) 1x4x20 3/4″ (short leg brace)

I have also listed below, the hardware and tools I used:

  • (8) 1/2″ x 6″ Hex Bolts
  • (8) Disk Washers
  • (8) Lock Washers
  • (8) Lock Nuts
  • 1/2″ Wrench
  • 1/2″ Socket and Ratchet Wrench (long is leverage)
  • 1/2″ Auger bit
  • Tons of screws (I forget the specs… I’ll come back to those)
  • Countersink bit
  • Powerful Drill (or in my case…)
    • (2) Weak-ass Drills
  • BF Hammer
  • Swanson 12″ Combo Carpenter’s Square (these are da BOMB!)
  • Tape Measure
  • Titebond Glue
  • Sandpaper (60 and 120 grit)
  • Sharpened Pencil
  • Plenty of Diet Coke
  • Plenty of Sam Adams (for after the job)

Here is the gallery of images taken since my last post.

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JMeter – Results Tree DateTime Conversion

Jakarta_jmeter_logoThis is more of a note to myself but feel free to use it.

This week, I have been performing load testing on a site at work.  After completing the first round of testing, I went to look at the data which was saved as a CSV file and discovered that the datetime stamp was an epoch.  While this is normally not an issue, I struggled with the conversion in the spreadsheet for a while until I finally cracked the nut.  Here’s the formula:


I won’t pretend to understand all of this.  However, the ‘14400000’ is the number of hour in milliseconds from GMT.  Gotta run… Use great power with responsibility 🙂



Workbench – My Continued Adventures in Woodworking

This weekend, while cleaning out the garage, I decided that I needed a new workbench.  For the past two years, I have been working off a banquet table that up until now has been adequate.  Some of the issues that I have with the banquet table is that it’s pretty damn wobbly. When I am planing or scraping or sawing, I must first clear everything off the table or my violent actions will take care of that in a negative way.  I crippled my twenty pound tool box as it went crashing to the floor.  Oops…  Also, the table is too low.  At a height of 29″, I find myself stooping over my work and ending my day with a crinkled back (yeah, I said ‘crinkled.’  It’s a medical term… look it up).  The one nice thing about the table is that when I need extra space, I can find a home for all my stuff and just fold it up and put it away.  However, that’s a compelling reason to not make the upgrade (and probably a contributing attribute to the instability of the table for the task of woodworking).

So, I set out to build something that was easy and cheap.  I am not the master woodworker.  I need a functional, sturdy workbench that is big enough to accommodate my guitar, electronic, and other handyman duties.  To the Depot!

My plan was simple.  Make the bench dimensions the same as the table approximately 28″ x 50″.  I needed only to raise the work surface to about 36″ which seems to be a height that works both sitting and standing.  I plan to use 2x4s for the structure and 2x8s for the work surface.  I don’t really have the tools to mill lumber, but I’m not too concerned with that.  The 2x10s will have the divots between the timbers but I’m fine with that too.  I plan to top the bench with 1/4″ MDF.  It’s strong enough to give me a nice, flat surface and easy to replace when I drop a piano on it.

Here’s roughly the dimensions of the parts (I was kind of winging it):

8, 36″ 2x4s for the legs – Cut to 34″ after laminating
2, 50″ 2x4s for the long sides of the table top – cut to 50 inc
2, 23″ 2x4s for the short sides – the actual width of the 2×10 is 9 & 1/16″ wide
3, 54″ 2x10s for the top


  • Add MDF top to surface
  • Shelf under bench
  • locking wheels so everything can move around

I planned to have a 2″ lip on the tabletop so the bench frame is is 4″ shorter than the top.

I started off with cutting the 2x4s on the miter saw.  This took about 10 minutes after measuring off 36″ from my 4, 96″ 2x4s. Next, I cut the two 50″ inch frame lengths and finished off with the frame widths.  The widths, I cut long in case I had bad math in my wingy dingy plan.

Next, I pulled out the 8 leg halves and began laminating them.  I matched the best looking faces for the exterior (like it matters with this project) and applied ample amounts of Titebond to both surfaces, then clamped them and let them sit for 24 hours.  Rinse and repeat 3x.

So, this is where I’m at right now.  I’ll post more pictures as I start getting this together.

Beaglebone Black : Get More Space From Your SD Card

sandisk-micro-8While researching for my post, “Backing up your Beaglebone Black“, I came across an article that demonstrated how to expand the linux partition from the standard image size.  I use an 8GB card and after flashing my sd card with the Ubuntu image, I had roughly 4GB of unused space.  Since space is at a premium, I have added external USB drives to help with that but leaving 4GB on the table is just silly.  So I decided to fix that today.

Even though I’m doing this on an Ubuntu instance, this should work for Angstrom instances as well.  However, be forewarned that this is potentially dangerous for your file system.  Make backups, double-check your work, and test this out on an install you can afford to lose before doing it on one you can’t.  Warning over.  Let’s get back to throwing caution to the wind.

First, let’s take a look at what we’re working with.  As root, run:

fdisk -l

This will spit out a list of all the partitions on your BBB.  The one we are concerned with today is mmcblk0.

Now, using the fdisk utility, we can resize the card while in the BBB.  We’re going to delete the existing partition, then create a new one, expanding its size and then wrap it all up with a bow on top.

Let’s start with:

fdisk /dev/mmcblk0

You will get a prompt:

Command (m for help):

If you’re curious, enter ‘m‘.  You should be safe here, just don’t enter ‘w‘ which is write! If you’re unsure at any time, you can enter ‘q‘ to bail without committing.

Here’s the sequence to resize the card:

root@ubuntu-armhf:~# fdisk /dev/mmcblk0

Command (m for help): d
Partition number (1-4): 2

Command (m for help): n
Partition type:
 p primary (1 primary, 0 extended, 3 free)
 e extended
Select (default p): p
Partition number (1-4, default 2): 2
First sector (4096-15523839, default 4096): <enter>
Using default value 4096
Last sector, +sectors or +size{K,M,G} (4096-15523839, 
default 15523839): <enter>
Using default value 15523839
Command (m for help): w

The partition table has been altered!
Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: 
Device or resource busy. The kernel still uses the old table. 
The new table will be used at the next reboot or after you run 
partprobe(8) or kpartx(8)
Syncing disks.


Now, since the partition is currently in use, we won’t see any change until we reboot. Let’s do that now:

shutdown -r now

When the BBB comes back, you will have a 4GB partition in an 8GB partition.  We can fix that with a utility called resize2fs.  Here’s how to use it.  As root run this command:

resize2fs /dev/mmcblkp2

When this command completes, reboot again and then run ‘df -h‘.  Here’s what mine looks like:

dfrey@ubuntu-armhf:~$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mmcblk0p2 7.3G 1.4G 5.6G 20% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
devtmpfs 248M 4.0K 248M 1% /dev
none 50M 244K 50M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 248M 0 248M 0% /run/shm
none 100M 0 100M 0% /run/user
/dev/mmcblk0p1 1004K 472K 532K 48% /boot/uboot

Personally, I think this is a better solution than the USB drive but the USB drive works for backups and supporting content like MP3s, videos etc to host on my WordPress site. Space is still at a premium but at least now I have a little more breathing room.

Beaglebone Black : Issues with Java on Ubuntu

java-duke-logoWhile I was starting work on my next walk-through, I discovered that I had not installed Java on my Ubuntu instance.  I don’t know why other than it simply didn’t come up.  When I originally installed it, I did it on Angstrom and had no issue.  Well, it was most certainly a different story with Ubuntu.

I downloaded the ARM version of JDK 1.7 from and attempted to unpack it with this command:

tar -xvpzf jdk-7u40-linux-arm-vfp-hflt.tar.gz

Instead of a stream of files being strone across my screen, I received an error message:

gzip: stdin: not in gzip format
tar: Child returned status 1
tar: Error is not recoverable: exiting now

I thought that I had corrupted my instance so I unpacked my latest backup.  As a side note, I dug around a bit and discovered how to overwrite existing files.  Here’s that command:

tar --overwrite -xvpzf bbb-ubuntu.tar.gz

This reset my BBB to my standard setup.  After attempting to unpack the Java tarball again, I received the same error.  I also unpacked the package on my host machine and then moved it over to the BBB and attempted to run Java.  It looked at me like I was daft and replied with:

-su: jdk1.7.0_25/bin/java: No such file or directory

Hmmmmm.   Time for Dr. Google.

I found the answer in teensy sized print in the middle of a answer:

sudo apt-get install libc6-*

This adds/updates a buch of files (took about 15 minutes to download and install) but it didn’t seem to be too large (about 50MB).

Once this was complete, I was able to unpack my JDK files, then from the bin directory,  I ran java -version and received:

java version "1.7.0_25"
 Java(TM) SE Runtime Environment (build 1.7.0_25-b15)
 Java HotSpot(TM) Client VM (build 23.25-b01, mixed mode)

Now I can get back to work

BeagleBone Black : WordPress On Ubuntu


Installing LAMP and WordPress on Ubuntu Running on A BeagleBone Black

Since I have been using WordPress with a couple blogs for almost 8 years now, I am fairly comfortable with the platform.  With my weekly BeagleBone Black challenges of late, I felt that installing WordPress would be a great idea to try.  I can tell you that the BeagleBone Black, once again, didn’t disappoint.

Before we begin, I want to just say that running WordPress on the BBB is an academic endeavor.  I wouldn’t think about hosting a public blog due to performance with this configuration but it is perfect for my needs as a teaching tool.  My oldest son just turned seven and is incredibly inquisitive about science.  He catches bugs, lizards, etc. and takes pictures of them.  He loves astronomy and never stops asking when the sun will go supernova.  I thought it would be a great for him to document his findings in a blog to teach him more about the scientific method, documenting his findings and getting more comfortable with the computer.  As an added bonus, I want to see where this takes him.

Getting Started

penguin-ubuntuAs I mentioned my previous blog, I created a “snapshot” of sorts by starting off with a fresh version of Ubuntu then adding my base setup changes then finally creating the tarball of the entire OS.  This way, I can simply reflash the card, restore my base install and begin on the next project.  That’s what I am doing with this.  This is basically my setup:

BeagleBone Black – Installing Ubuntu – Part 1

BeagleBone Black – Installing Ubuntu – Part 2

Beaglebone Black : Back Up Ubuntu

I didn’t include the wireless, cloud9, or OpenGate for this because I wasn’t sure where I was going to put WordPress and was concerned with space.  Turns out, that space wasn’t an issue (other than bleeding off CPU cycles).

Once I had my base install configured, I needed to install and configure three additional components before WordPress:

  • mySQL Database
  • Apache Web Server
  • PHP Scripting Language

This comprises what is called a LAMP server (Linux Apache Mysql Php)

Installing LAMP on BeagleBone Black Ubuntu

At first, I thought this was going to be easy.  I found a package in the package manager for installing LAMP and tried it out.  I’m not saying it doesn’t work, but I will say that I had to reflash a couple times and it never really worked well for me.  Also, I really wanted to have a little more control over what I was installing, so I ended up installing and configuring each component separately.  We’re going to do that here.  I based my steps off a couple walk-through guides found on Ubuntu Server Guide and (links to these and other resources will be found at the end of this walk-through).

MySQL Installation and Configuration

Real quick, before we start installing packages, let’s make sure we’re up to date with everything:

sudo apt-get update
sudo apt-get upgrade

Since we already have the Linux part of LAMP, let’s move to mySQL. You can install this with a simple command of:

sudo apt-get install mysql-server

You will be prompted to provide a password for the root account.  It is always strongly advised to do so and remember this password.  If you forget, you won’t be able to move forward.

Once the install is complete, we need to test the install and then create a database for our installation.  Before we continue, think about the name or type of WordPress site you want to create.  Since mine is to help teach my son about science, I will call mine, ‘science’.  You want to keep it small and if you have more than two words, separate with underscores or dashes (‘_’ or ‘-‘).

To test your installation, type:

mysql -u root -p

You will be prompted to for the password you provided during the installation.  Once you have successfully done this, type:

show databases;

This command will list out a table of databases that are currently available.

mysql> show databases;
| Database           |
| information_schema |
| mysql              |
| performance_schema |
| test               |
4 rows in set (0.01 sec)

If you have made it this far, you are ready to continue.

Now we need to create a user, a table, and provide permissions.  I used ‘scienceadmin‘ for the username and ‘science‘ for the database.  Simply replace these with your credentials.  Oh, and with these commands, don’t forget the semicolon. If you do, it’s not a big deal, just type `;` on the next line and the command will execute.

Create the Database:

create database science;

Create the user:

create user scienceadmin@localhost;

Set a password for this user:

set password for scienceadmin@localhost=password("squirrelhunter01");

Create the permissions for this user to use the database:

grant all privileges on science.* to scienceadmin@localhost identified by 'squirrelhunter01';

Finally, let’s refresh MySQL:

flush privileges;

To get out of mySQL:


Installing Apache Web Server

beagleThis will be pretty straight forward.  To install the web server, you enter in:

sudo apt-get install apache2

After the install you can start it up with this command:

sudo service apache2 start

and test it in your browser: “http<beaglebone IP or personalized hostname>/”

You should see the “It Works!” page.

We’re done with Apache for now.

Installing PHP

To install or update PHP, run the following command:

sudo apt-get install php5 libapache2-mod-php5 php5-mysql

Once this is complete, let’s test it.  Navigate to /var/www and create a file named, ‘test.php‘ then add the following text:


Next, fire up a web browser and navigate to `http://<bbb_IP>/test.php`.

You should see a page filled with server/site/php goodness.

And we are done with the LAMP installation.  Easy right?

WordPress Install and Configuration

Now we get to the meat of this walk-through.  Let’s first decide where we’re going to put our WordPress site.  When you download WordPress and unpack it, you can put it in your root or in a sub-folder.  You an even have several instances running at the same time in several folders.  When I was working through this, I went a road less traveled by putting the site on a thumb drive and created a symlink from the web server root.  This creates quite a mess (I will write up a way to do this shortly) but for the purpose of getting a wordpress site up and running, we’ll start with the easy way.

The Easy Way

At this point, I am showing 1.1 GB of free drive space.  This should be more than apache_featherplenty to run WordPress right off the BBB.  First let’s download the WordPress files.  I can simply download the latest version to my home directory like this:

dfrey@ubuntu-armhf:~$ cd
dfrey@ubuntu-armhf:~$ wget -O wordpress.tar.gz
dfrey@ubuntu-armhf:~$ tar -xvpzf wordpress.tar.gz


Now, we should have the WordPress site files that I can copy to any directory.  Let’s try it out in the root of our web site.

sudo cp -r wordpress/* /var/www/

This just copied all the files to the root of my web server.  Let’s go check it out in the browser: `http://<bbb_ip>/`

huh?  We still get the same message as before.  Well, this is because we need to configure a couple things.  Since this is a manual installation of WordPress, we have a little more work to do but it’s easy.

In your browser, navigate to, `http://<bbb_ip>/wp-admin/`

You should see a message indicating the wp-config.ini is missing.  Click the `Create a Configuration File` button and you will navigate to the setup configuration introduction page.  You are going to need to have the following ready (we did most of this already so it’s no big deal).  I’ll add my info from above as an example:

  1. Database name – ‘science
  2. Database username ‘scienceadmin
  3. Database password ‘squirrelhunter01
  4. Database host ‘localhost
  5. Table prefix (if you want to run more than one WordPress in a single database) – You can create whatever prefix you like.  If I were going to put more than one WP site in the same database on this BBB, I would choose, ‘sci_‘, but for now we’ll go with ‘wp_

And click ‘Submit

When I ran this, The wp-config.php file couldn’t be written.  Not that this is a huge problem now but it will be shortly so let’s address this issue now.

We installed Apache as root, so the folders that where created by the installer are owned by root.  Apache runs under a user named www-data.  We need to change the ownership of the www folder so that apache can do it’s magic.  Navigate to /var then run this command:

sudo chown -R www-data:www-data www

This will change the ownership and group membership of the www folder and everything underneath it.  Now we can continue.  Hit your back button in the browser so you can see the configuration form again.  Click submit again and you should now get the “All right Sparky…” message indicating the config file was created successfully.

Now, let’s head on to setting up the actual WordPress site.   Click the “Run the Install” button.  Here, you will enter the title of the site that displays on the header,  the user name of the site administrator and the password for this user.  Don’t worry.  You didn’t miss anything, we’ll create this account inside of WordPress now.  These are for the site not the database.  They can be completely different or exactly the same.  It’s up to you.

Site Title:     Science
Username:  scienceguy
Password:   tesla@24
Email: (just made that up)
Privacy:       (turned this off)

Now click on the ‘Install WordPress` button.  The scripts will run for a while then take you to the `Success Page`.  Click Login then enter your username and password.  If everything was done correctly, you now have a spanky brand new WordPress site.

After installing, I still have just under 1GB of space left.  If you intend to install other things on your BBB, you might want to install other things off the board, on a thumb drive.  That walk-though will be coming in a couple days.

Oh, I forgot one thing.   You need to remove two files from your /var/www folder:

  1. index.html – this will override the WordPress pages (its why we didn’t get an error when we tried it before configuring WordPress)
  2. test.php – this has some server-specific information that a hacker could use against your BBB.

Now got to `http://<bbb_ip>/&gt;` in your browser and you will see the public version of your site.  Go WordPress Crazy and have fun.

Feel free to leave comments if you have any questions or if you found this walk-though useful.

I got so excited to post this, I forgot my link references.  Here you go: