BeagleBone

Sure, the BeagleBone and BeagleBone Black come with an ethernet port on them, but why have to get another cable out? You might not even be anywhere near the router. The BeagleBone images automatically do network communcations over USB, as shown by how you can go to 192.168.7.2 from your browser to see the BeagleBone start page and http://192.168.7.2:3000/ to use the Cloud9 editor hosted on the BeagleBone. The problem is that the host computers do not usually relay network traffic to new interfaces. I don't know why not. It would be nice if you could just connect stuff to any connection and it'd always work, but it's not hard to set up NAT and such once you know how to do it. The connection over USB might be slighlty slower than the dedicated connection, since USB is slower and is sharing the connection with things JTAG communication and mass storage. For all I know, though, the ethernet on the BeagleBone is actually controlled by the same USB controller, so it might not be at all different!

Since the BeagleBone (and the Raspberry Pi) is Linux based, and has usb ports, it is actually very easy (and cheap) to make a security camera system. All you need are USB webcams. Just about any will do. I got four for $16 on Amazon. More expensive ones might say they have higher resolution, but what they are actually reporting is the still photo quality, not streaming video quality. Unless you get a USB 3.0 webcam, which would not be supported by either hobbyist computer, it is impossible to stream HD (1080) video, but some might be able to 720.

Introduction

Angstrom Linux is what ships on the BeagleBones. It's kind of terrible because I think everyone when they first get it will say, oh I should run opkg upgrade so that everything is up to date. Guess what? That breaks the boot. It won't startup anymore. I don't know how to fix it or what goes wrong. You'll get three LED's on, no USB connection on either the mass media or network, and it'll never come online on the LAN because it won't start up. 

If you want things to be up to date, you may want to install Ubuntu.

On the other hand, it is pretty lightweight and is pre-configured in a lot of ways that other distros don't have by default. For example, the cloud9 editor is kind of nice.

Installing Images

Whether you have a BeagleBone or BeagleBone Black, you can use the Angstrom-Cloud9-IDE-GNOME-eglibc-ipk*.img.xz

They both run ARM7 and the image has the NEON optimization. The image for the BeagleBone Black might have additional features, but it's the same Angstrom with less features as far as I can tell.

sudo su
xz -cd ./Angstrom-Cloud9-IDE-GNOME-****.img.xz > /dev/sdd

About each LED

There are four user LEDs on the BeagleBone. You can modify them, but they each have their own purposes by default. USER0 is the closest to the top in the picture at the right, and USER3 is the bottom one closest to the ethernet port.

• USER0 is the heartbeat indicator from the Linux kernel.
• USER1 turns on when the SD card is being accessed
• USER2 is an activity indicator. It turns on when the kernel is not in the idle loop.
• USER3 turns on when the onboard eMMC is being accessed.

You can change each of the LED's behaviors at the following locations:

/sys/class/leds/beaglebone\:green\:usr0/
/sys/class/leds/beaglebone\:green\:usr1/
/sys/class/leds/beaglebone\:green\:usr2/
/sys/class/leds/beaglebone\:green\:usr3/

Yeah, the LEDs are blue, but the folder is called green for some reason. Also, those colons make BASH freak out a bit, so pay attention to escape them.

If you explore those directories, things start to get interesting.

Pinout Tables

These tables are based on the BeagleBone Black System Reference Manual (Creative Commons) by Gerald Coley of BeagleBoard.org. They aren't really available anywhere else on the internet, so I thought I'd transcribe them into a more available format.

Introduction

The BeagleBone Black is a very powerful and affordable microcontroller - superior to an Arduino Uno in a lot of ways. It's fast enough to be used as a desktop computer, yet it has more pinouts than an Uno. With the BeagleBone Black priced at $45, it's really a great value compared to an Arduino ($35) or even a Raspberry Pi ($35).

An Arduino, while power-efficient and reliable, is incapable of high performance use cases like image processing. Even the ARM based Arduino Due is thousands of times slower than the BeagleBone Black. It can't even parse a JPEG (the library won't fit in the flash). A BeagleBone or Raspberry Pi, however, can easily process live streams from USB webcams and OpenCV.

The BeagleBone Black is significantly faster and more capable than the comperable $35 Raspberry Pi Model B. Both have the same RAM, HDMI out, and Ethernet, but the BeagleBone Black has superior IO (more and faster) and has a faster processor capable of running Ubuntu, where the Raspberry Pi cannot due to its older architecture. Remember, Raspberry Pi was intended to be an educational tool to teach kids to program, not to help you hack together a robot. The BBB has two extra processors dedicated to effectively manage the pinouts.

The downside? The pre-installed OS (Angstrom) at this point in time will break if you do a package upgrade. Not only will it never boot again once it finishes updating, but it also uses too much of the /tmp/ filesystem and stalls halfway though. You can run Ubuntu on it, but there isn't much of a point, since it's basically incapable of having a desktop UI or using OpenGL as far as I can tell. There's no reason why it shouldn't be possible. In fact, LXDE and XFCE sort of work.  This leads to the bigger problem. The documentation, support, and community behind BeagleBone is nowhere near that of the Raspberry Pi, let alone Arduino (which has the best by far).