CaspaPX
The MT9V032 sensor at the heart off the CaspaPX is not yet supported in the kernel, so a little work is necessary to get the camera up and running.
Contents
Quickstart
The first steps are important to verify your hardware setup and to test your customizations later.
Install Pre-built Kernel
The easiest way to get started is to replace the kernel and modules of an existing image. This method was tested on an Overo Fire with a Tobi expansion board using the desktop image available here.
Get the kernel and modules.
$ mkdir ~/caspakernel $ cd ~/caspakernel $ wget cumulus.gumstix.org/images/caspapx/uImage $ wget cumulus.gumstix.org/images/caspapx/lib.tar.gz
Extract the modules.
$ tar -xf lib.tar.gz
Copy them to an Overo already running the image that you want.
$ scp lib/* root@overo:/lib/ $ scp uImage root@overo:/boot/uImage; $ scp uImage root@overo:/media/mmcblk0p1/uImage
Reset the overo.
$ ssh root@overo 'shutdown -r now'
This method is especially convenient for making modifications to the driver or kernel. See the customization section for more information.
Test
From the serial console:
# export -DISPLAY :0.0
# gst-launch v4l2src ! xvimagesink <or> # mplayer tv:// -tv driver=v4l2:device=/dev/video0
From the desktop:
<left-click on desktop> Applications > Multimedia > Cheese
Customization
Hardware Overview
The OMAP35X processors have dedicated hardware for capturing and processing data from image sensors. The CaspaPX camera sensor outputs raw 10-bit Bayer images which is transfered to the Image Signal Processor (ISP) via a parallel interface. The ISP contains various submodules that can be exported as V4L2 devices in /dev. For additional hardware information see the external links section below. The remainder of this section will deal with
MT9V032 Driver
If you want to take advantage of an unimplemented sensor feature, change defaults, etc., you need to modify the driver source. First, make sure that you
You can write scripts to make it even faster.
These steps will allow you to customize the camera driver and kernel for your own application.
Image Signal Processor
To get the best performance from the camera under other lighting conditions we need to get our hands dirty in the kernel source.
2.6.34
Get the kernel source that is used in the Gumstix kernel recipe (~/overo-oe/org.openmebedded.dev/recipes/linux/linux-omap3_2.6.34.bb) and create a new branch from the recipe SRCREV.
$ cd ~ $ git clone git://www.sakoman.com/git/linux-omap-2.6.git $ cd linux-omap-2.6 $ git checkout cb89736af28f583598e49a05249334a194d00f1d $ git checkout -b 2.6.34
Make a copy of the default kernel configuration to use as a starting point for your customizations.
$ cp ~/overo-oe/org.openembedded.dev/recipes/linux/linux-omap3-2.6.34/defconfig ./ $ cp defconfig .config
