WayneRoss.net: 2013

Saturday, December 7, 2013

Raspberry pi Vision processing

Got all the pieces plugged in
First off, selected the Raspbian OS distribution at the first NOOB boot prompt.
Got no VGA output on the first couple boot cycles, used "Safe mode" (hold shift key during boot) to bring up a shortcut to the settings, where I enabled the 2 lines for VGA.
In raspi-config, I selected the Enable Camera option, then Boot to Desktop.
The desktop comes up with a default resolution of 576x416 - painfully large!
Used safe-mode editor to alter //boot/config.txt:


disable_overscan=1

hdmi_force_hotplug=1

hdmi_group=2

hdmi_mode=16

found here

If you don't like the Great Britain keyboard layout, nano /etc/default/keyboard layout to 'us'
Straighten out the Time Zone with 'sudo dpkg-reconfigure tzdata'
connecting a RJ45 gives access to the web. If you need a static address, instructions can be found here.
Then it's time get the latest version of rasbian and set up the compiler and tools. I followed my own previous notes from January (git and build-essential were already installed)


sudo apt-get update

sudo apt-get install cmake libgtk2.0-dev python-dev libavformat-dev libswscale-dev

This installed 91 new packages for me.
Got the newest OpenCV 2.4.7 and extracted it to opencv-2.4.7. Terminal:

mkdir Paladins
cd Paladins
mkdir OpenCV
cd OpenCV

cmake ../../opencv-2.4.7

make                   ##    This took about 9 hours to run!!

sudo make install

Then following along with Josh Larson's post on Chief Delphi and pulling his code from github.

In Paladins:


git clone git://github.com/Josh-Larson/CameraBoardAPI

which builds a sub-folder CameraBoardAPI

pi locked up when running sudo apt-get upgrade, which is unfortunate. It was executing a series of "Remove 'diversion of ...' items, then indicated 'dpkg-divert: error: unable to sync file '/boot/start_x.elf.dpkg-divert.tmp': Input/Output error'. Completely non-responsive since. SD card failure? Out of space? Guess I should go get another card and try from scratch.

What I cannot figure out, is when I insert a working card from my pi, it still won't show any activity at boot.

So, starting over with another 4gb SDHC micro, I installed 2013-09-25-wheezy-raspbian.img (available as a torrent) on that card, and could only get video by plugging into my HDMI TV. There, I changed the config (as above) to VGA in //boot/config.txt again. Success!

Now, the sequence is to update Linux first, then do OpenCV!


sudo apt-get update

sudo apt-get upgrade                    ##  57 items updated

sudo apt-get install cmake libgtk2.0-dev python-dev libavformat-dev libswscale-dev  ### 89 items installed