BeagleBone Blog

This page contains my blog postings on the BeagleBone platform. Please pay careful attention to the date of the posting, as older posts are less relevant to recent developments on the BeagleBone platform.

UDP Unicast and Multicast Streaming Video using the Beaglebone Black

Introduction
In a previous post, I described how you could set up the Beaglebone Black to capture video and process video using OpenCV with the Logitech C920 camera. In this post I am going to look at how you can begin streaming data using the camera and code that I had adapted previously. The previous post is here and the final instructional page is here. I also just posted on how to stream video data using RTP.

This post looks at how you can stream video using UDP unicasting and multicasting. UDP unicasting is very similar to the RTP stream from before except there is no need to distribute a configuration file to the client via RTP or RTSP. The downside of unicasting is that the video transmitter needs to know the destination address of the receiver – kind of the opposite of what you might expect!

UDP Multicasting allows you to have many […]

Streaming Video using RTP on the Beaglebone Black

Introduction
In a previous post, I described how you could set up the Beaglebone Black to capture video and process video using OpenCV with the Logitech C920 camera. In this post I am going to look at how you can begin streaming data using the camera and code that I had adapted previously. The previous post is here and the final instructional page is here. I hope to follow this post up with a video shortly as soon as I address all of the issues I would like. I have also just released a post on how to stream video using UDP unicast and multicasting. I am going to view the video using VLC on a Windows 7 PC.
Acknowledgement
This post is based heavily on work by William C Boner and OZ9AEC and I would recommend that you read the work on their blogs as there is plenty of information there on getting video streaming to work. I […]

GPIOs on the Beaglebone Black using the Device Tree Overlays

This post provides supplementary information to the video that I have just posted on using GPIOs with the Beaglebone Black.
The Video
In this video I am going to continue my series on the Beaglebone by demonstrating how to use its GPIOs for both input and output applications. In this video I will wire simple input and output circuits that are attached to two GPIOs – one that lights an LED and the other that receives a button input. I covered this topic below before in a previous video. I am updating it here because there have been significant changes to the Linux kernel. This video will cover the Linux device tree for ARM embedded systems and explain how you can create custom device tree overlays to configure the GPIOs for your applications at run time from within the Linux userspace. I will explain the use of internal and external pullup and pulldown […]

Git and Curl SSL Certificates Configuration on Beaglebone Black

I have noticed that on the Beaglbone Black that I am constantly having problems with git and curl when it comes to https sites. This post addresses the configuration problems and shows you different ways to solve the problem that may suit your particular needs.
Fixing the SSL problems with Git
Out of the box, if you try to commit to a github repository using https (a requirement of github) then you will have difficulties with certificates. The error you will get looks like this (I’m using -v for verbose mode):

Under older versions of git, the problem may also appear as:

You could of course fix this by using git://github.com/derekmolloy/boneCV.git as the repository address; however, this does not fix the problem when you try to commit to the repository. In fact, the same error will arise.

Solution 1 – The super-easy but bad solution!

Simply use the git global preferences to turn off SSL  verification:

A […]

Building git from source for the Beaglebone Black

I use github.com for all of my source code source version control. I noticed that in the past few days git push had stopped working for me on the Beaglebone Black (BBB) for one of my repositories. I decided to build git from source to see if it was a version issue. The version of git on the BBB is version 1.7.7 and it appears that this is quite old. A “opkg install git” keeps it a slightly higher revision of version 1.7.7.

There were quite a number of small issues to resolve, so I have written this up to remember them for the future and make them available to all.
Building Git for the Beaglebone
Find the version of git that you would like to install: https://www.kernel.org/pub/software/scm/git/

I’m going to build and install 1.8.3, a fair update from 1.7.7.

First we need to download the source code. I cannot get wget to work with https links on […]