About Derek

Dr. Derek Molloy is a senior lecturer in the School of Electronic Engineering, Faculty of Engineering and Computing, Dublin City University, Ireland. He lectures at undergraduate and postgraduate levels in object-oriented programming with embedded systems, digital and analog electronics, and 3D computer graphics. His research contributions are largely in the fields of computer and machine vision, 3D graphics, embedded systems, and e-Learning. This is his personal blog site.

Set Static IP Address on the Beaglebone Black


The BBB is configured by default to use the dynamic host configuration protocol (DHCP) for the allocation of its wired and wireless IP address. Network routers typically run a DHCP server that allocates a pool of addresses to devices attached to the network. While DHCP works well for most devices on a local network, it can cause difficulties if you […]

By |May 27th, 2013|Beaglebone, Blog|76 Comments

Writing a new Image to the Beaglebone Black

 Although the BBB is supplied with a Linux distribution already on its eMMC, one of the first steps you may carry out is updating your BBB to have the latest Linux distribution.
The website has very clear instructions on writing a new system image to the BBB, so this section only details observations and additional steps that may be […]

By |May 26th, 2013|Beaglebone, Blog|116 Comments

Beaglebone Images, Video and OpenCV

Please note: this was an early post – the content of this post was turned into a video that is available on this page: Beaglebone: Video Capture and Image Processing  on Embedded Linux using OpenCV
Getting started

Start by plugging in the camera with the power down and then booting, praying that the device is picked up. lsusb is a utility for displaying […]

By |May 23rd, 2013|Beaglebone, Blog|47 Comments

Changing the Beaglebone CPU Frequency

Check the CPU Frequency
 The BBB has various governors that can be used to profile the performance/power usage ratio. For example, if you were to build a battery powered BBB application that required low processing requirements, you could reduce the clock frequency to conserve power. You can find out information about the current state of the BBB by typing cpufreq-info:

You can see […]

By |May 23rd, 2013|Beaglebone, Blog|18 Comments

Automatically Setting the Beaglebone Black Time Using NTP

Setting the Time on a Once-off Basis
On my current distribution the Beaglebone Black does not come with a working NTP installation in order to set the time. Because the board doesn’t have a battery backup, this means that we need a way to set the time when the board is running. If you wish to set the time you could […]

By |May 18th, 2013|Beaglebone, Blog|83 Comments

Custom Kernel and Ångström Distribution Recipe (SPI/CAN bus Support)

I have already posted on how we can build a vanilla Angstrom distribution from source at this post: Building Angstrom for Beaglebone from Source. This post looks at how we can add SPI to the kernel and rebuild the Linux kernel and Angstrom distribution. The post isn’t specific to SPI, so it may be that you are looking to make […]

By |May 5th, 2013|Beaglebone, Blog|14 Comments

Driving LED Arrays

I have started to investigate how I can drive a large bank of LEDs directly from my Beaglebone or Raspberry PI. I have developed a video before:

where I drove a 2 colour 8×8 LED common anode dot matrix display using three 74HC595s and a transistor array UDN2981A to source the current. This used the Arduino as the platform to drive […]

By |April 28th, 2013|Beaglebone, Digital Electronics, Raspberry PI|3 Comments

Remove index.php from your WordPress URL

You will notice that this site which runs using WordPress that there is no index.php in the URL when you are directly addressing a page/post or when you are linking to other pages/posts. This can achieved using the following configuration.
There are two step 1’s, depending on whether you/your web provider is using Apache or Zeus scripting. To […]

By |April 27th, 2013|Blog|22 Comments

Building Ångström for Beaglebone from Source

The Ångström distribution is a Linux distribution for many embedded devices, the Beaglebone included. Here I am going to document the steps that I took in order to build a full distribution of Angstrom (easier to write without the unusual letters). I am working from the steps described at this site: but here I will document any difficulties and the times […]

By |April 23rd, 2013|Beaglebone, Blog|36 Comments

Resize a VirtualBox guest Linux VDI Disk under Windows Host

My Linux VirtualBox guest OS often runs out of space – I never learn that to build anything in Linux, you need about 10 times the amount of space that you think you need. Also, VirtualBox recommends very small default values, so it is easy to be caught out.

Anyway, here are the current steps to re-size a VirtualBox disk, where Linux is the […]

By |April 21st, 2013|Blog, General, Linux|158 Comments