Dev/Caspa
This page describes the ongoing work to fully integrate a Caspa FS camera on a Lisa/L board. Any advices/suggestions/contributions are welcome.
Final Goal
The final goal is to have a Caspa FS camera connected to the Overo chip on a Lisa/L board. The Overo chip should be able to communicate with the STM32 via SPI. The link shall be used to transmit the result of the image processing computed by the Overo. However this should be flexible enough to let some room for the developer to decide which processing to do and which kind of data to send. Digital video streaming to the groundstation is also interesting.
Caspa camera on an Overo expansion board
As a first step a simple connection between the camera and the Overo was tried using an Overo expansion board, i.e. not the the Lisa/L board.
Hardware components
Step-by-step
Create a bootable MicroSD card if you do not have one
Follow this and use LABEL1 as 'mmcblk0p1' and LABEL2 as 'mmcblk0p2'.
Load a pre-built standard image
sudo chown [user_name] /media/mmcblk0p1 sudo chown [user_name] /media/mmcblk0p2 wget http://cumulus.gumstix.org/images/angstrom/factory/2011-03-25-1619/omap3-desktop-nand-image-overo-booted.tar.bz2 tar -xjf omap3-desktop-nand-image-overo-booted.tar.bz2 -C /media/mmcblk0p2 // ignore errors wget http://cumulus.gumstix.org/images/angstrom/factory/2011-03-25-1619/MLO wget http://cumulus.gumstix.org/images/angstrom/factory/2011-03-25-1619/u-boot.bin wget http://cumulus.gumstix.org/images/angstrom/factory/2011-03-25-1619/uImage cp MLO /media/mmcblk0p1 cp u-boot.bin /media/mmcblk0p1 cp uImage /media/mmcblk0p1
When populating mmcblk0p1 it is important to copy the MLO first otherwise it will not be found by the Overo booting mechanism
Replace some files to get the camera modules working
wget http://cumulus.gumstix.org/images/angstrom/misc/caspapx/uImage-2.6.34 wget http://cumulus.gumstix.org/images/angstrom/misc/caspapx/modules-2.6.34.tgz tar -xf modules-2.6.34.tgz -C /media/mmcblk0p2/ cp uImage-2.6.34 /media/mmcblk0p1/uImage cp uImage-2.6.34 /media/mmcblk0p2/boot/uImage
Attach the camera to the Overo board
Insert the white ribbon cable contact-side-up into the Caspa connector and contact side down into the Overo connector.
Insert MicroSD card in the Overo board
Set environment variables
- Connect the expansion board to the host machine via USB B (Console)
- On the host machine do:
[sudo apt-get install ckermit] kermit -l /dev/ttyUSB0 C-Kermit>set flow-control none C-Kermit>set carrier-watch off C-Kermit>set speed 115200 /dev/ttyUSB0, 115200 bps C-Kermit>connect Connecting to /dev/ttyUSB0, speed 115200 Escape character: Ctrl-\ (ASCII 28, FS): enabled Type the escape character followed by C to get back, or followed by ? to see other options.
You have now a console connection to the Overo
- Power-up the expansion board
- Hit 'Enter' to interrupt the boot sequence
- Type in the console:
nand erase 240000 20000 reset
This makes the Overo to read the environment variables defined by the kernel in the MicroSD. You just have to do this once after setting up the card.
- Hit 'Enter' to interrupt the boot sequence again
- Type in the console:
setenv defaultdisplay lcd43; saveenv; reset
You just have to do this once after setting up the card.
Get the image
- Let the Overo boot properly
- Touch the screen and calibrate it as indicated. You just have to do this once after setting up the card.
- Type in the console:
overo login: root export DISPLAY=:0.0 mplayer tv:// -tv driver=v4l2:device=/dev/video0 -x 480 -y 272 -vo x11
The camera image should appear on the LCD display.
Based on Gumstix wiki.
WiFi digital video streaming
Here we show how to achieve WiFi digital video streaming with the Lisa/L board. This setup can be used as a parallel system to the autopilot running in the STM32. However, as connection from the Overo to the STM32 is envisaged we try to prepare the Overo kernel for SPI support (not tested yet).
Hardware components
Step-by-step
The general idea is to build a Linux kernel and a filesystem image for the Overo board which supports both the Caspa camera (sensor mt9v032) and SPI. Aside from this we use the DSP for encoding the image and WiFi for streaming to the groundstation.
It helps if you have notions of Bitbake & OpenEmbedded and git. Otherwise you can try doing it in a mindless way and it should also work. For that follow only the steps marked with a (*).
Get the Overo toolchain
$ cd ~ $ mkdir overo-oe $ cd overo-oe $ git clone git://gitorious.org/gumstix-oe/mainline.git org.openembedded.dev $ cd org.openembedded.dev $ git checkout --track -b overo4lisa-2011.03 origin/overo-2011.03
$ cd ~/overo-oe $ git clone git://git.openembedded.net/bitbake bitbake $ cd bitbake $ git checkout 1.10.2
$ cd ~/overo-oe $ cp -r org.openembedded.dev/contrib/gumstix/build . $ source build/profile
This last command is required whenever you want to use bitbake. More info here.
Changes to the original repository
In org.openembedded.dev/conf/machine/overo.conf edit the lines:
'SERIAL_CONSOLE = "115200 ttyO2' to 'SERIAL_CONSOLE = "115200 ttyS2' 'PREFERRED_PROVIDER_virtual/kernel = "linux-omap3"' to 'PREFERRED_PROVIDER_virtual/kernel = "linux-omap3-caspapx"'
This will make kernel 2.6.34 to be compiled instead of 2.6.39 which has no support for the camera at the time of writing.
Now we need to give the right configuration before compiling the kernel. Here you can choose to do it yourself:
$ bitbake -c menuconfig linux-omap3-caspapx $ cp ~/overo-oe/tmp/work/overo-angstrom-linux-gnueabi/linux-omap3-caspapx-2.6.34-r101/git/.config ~/overo-oe/org.openembedded.dev/recipes/linux/linux-omap3-caspapx/overo/defconfig
Add support to the mt9v032 sensor, disable touchscreens and LCD displays (which use the same I/O lines as SPI) and add support to SPI.
Or you can use the same configuration as I did:
$ wget https://raw.github.com/gist/1094791/a97f9a16556d3986ba1ceabd2ab9d4898b75244f/linux-omap3-caspapx-kernelConfig $ cp linux-omap3-caspapx-kernelConfig ~/overo-oe/org.openembedded.dev/recipes/linux/linux-omap3-caspapx/overo/defconfig
Notice in the configuration file the line 'CONFIG_SOC_CAMERA_MT9V032=m'. This means that the mt9v032 sensor driver will be added to the kernel as a module. This is a better approach because then you can load and unload it for changing operational configurations like auto exposure features.
Then, I modified the original filesystem image recipe so that every necessary component is included. Do:
$ wget https://raw.github.com/gist/1094809/bf6ce898134fe4ef96bfc0ba7ecac7577583d2b8/omap3-overo4lisa-image.bb $ cp omap3-overo4lisa-image.bb ~/overo-oe/org.openembedded.dev/recipes/images/omap3-overo4lisa-image.bb
Finally, follow the step 'Building task-gstreamer-ti' in jumpnowtek but do not run the last 2 commands.
Compiling the kernel
$ bitbake -c clean linux-omap3-caspapx $ bitbake linux-omap3-caspapx $ bitbake x-load $ bitbake u-boot-omap3
Building the filesystem image
$ bitbake omap3-overo4lisa-image
Load a bootable microSD card
See Create a bootable MicroSD card if you do not have one.
$ cd ~/overo-oe/tmp/deploy/glibc/images/overo $ cp MLO-overo-1.44+r20+gitr24b8b7f41a83540433024854736518876257672c-r20 /media/mmcblk0p1/MLO $ cp u-boot-overo-2010.9+r1+git1e4e5ef0469050f014aee1204dae8a9ab6053e49-r1.bin /media/mmcblk0p1/u-boot.bin $ cp uImage-2.6.34-r101-overo.bin /media/mmcblk0p1/uImage $ tar -xvf Angstrom-omap3-overo4lisa-image-glibc-ipk-2011.03-overo.rootfs.tar.bz2 -C /media/mmcblk0p2 $ tar -xf modules-2.6.34-r101-overo.tgz -C /media/mmcblk0p2
File names might change a bit. Change the commands accordingly.
In /media/mmcblk0p2/etc/inittab edit the line:
'S:2345:respawn:/sbin/getty 115200 ttyO2' to 'S:2345:respawn:/sbin/getty 115200 ttyS2'
This is due to an incompatibility among kernel versions. The earlier ones use the ttyS2 console while the newer use ttyO2. Not editing this line prevents us from using the console.
Load a bootable microSD card with a prebuilt kernel and filesystem (*)
ToDo
Setup WiFi connection
In /media/mmcblk0p2/etc/network/interfaces add the lines:
auto wlan0 iface wlan0 inet static wireless_mode ad-hoc wireless_channel 1 wireless_essid caspa address 192.168.0.202 netmask 255.255.255.0
Setup (p.e via NetworkManager) a similar network in the groundstation side and give to this the address '192.168.0.200'. Of course other configurations are possible.
Edit u-Boot parameters (*)
- Put the microSD card in the Overo board.
- Connect the expansion board to the host machine via USB B (Console)
- On the host machine do:
[sudo apt-get install ckermit] kermit -l /dev/ttyUSB0 C-Kermit>set flow-control none C-Kermit>set carrier-watch off C-Kermit>set speed 115200 /dev/ttyUSB0, 115200 bps C-Kermit>connect
You have now a console connection to the Overo.
- Power-up the expansion board
- Hit 'Enter' to interrupt the boot sequence
- Type in the console:
nand erase 240000 20000 reset
- Interrupt again the boot sequence
- Follow the step 'U-Boot Kernel Parameters' in jumpnowtek (Gumstix procedure)
- Finally type:
reset
Streaming (*)
Now the Overo is ready to start streaming. Set up the connection in the groundstation with NetworkManager. A blue LED should light up in the Overo board indicating that it is wireless connected. Use the following:
$ wget https://raw.github.com/gist/1094865/efc9578a0fa23784636d0ef02d9281e8b490dcca/videostreaming.sh $ sudo chmod +x videostreaming.sh $ ./videostreaming.sh
This connection was tested in open field with a simple laptop without external antenna. Ranges of 75m are possible. However the image quality in bright lighting conditions is low for all distances.
Based on jumpnowtek.
Troubleshooting
- Gumstix ships two types of this camera. One with IR filter (version VL - PCB30009C) and one without (version FS - PCB30009). However the board might be mislabeled and so the only way to know your version is to unmount the lenses and check for the IR filter.
- If you are OK with disabling the auto exposure driver feature this can increase a lot the image quality and reliability. For changing driver parameters you have to add mt9v032 sensor support to the kernel as module and not as a built-in feature. Then:
$ rmmod mt9v032 $ insmod /lib/modules/2.6.34/kernel/drivers/media/video/mt9v032.ko auto_exp=0
Work in progress
- C code for image grabbing using OpenCV
- SPI communication between Overo and STM32
- Camera tunning possibilites