ovc2

On the OVC2, the TX2 simply configures the FPGA over SPI. Because there are no flash memories outside the TX2, the update process is considerably simpler than on the OVC1.

Update source tree

cd ~/ovc
git pull

Compile kernel module

cd ~/ovc/software/ovc2/modules/ovc2_core
make
cd ~/ovc/software/ovc2/modules/ovc2_cfg
make

In case there is a compilation error for ovc2_core, try

cd /usr/src/linux-headers-4.4.38-tegra/
sudo make modules_prepare

Compile ROS package (userland)

mkdir -p ~/ros/src
ln -s ~/ovc/software/ovc2/ros/ovc2 ~/ros/src
cd ~/ros
catkin build

how do I run stuff

For convenience, the ~/.bashrc of the default nvidia user adds ~/ovc/software/ovc2/scripts to $PATH. Create a link for the ovc2a.rbf file (located at ~/ovc/firmware/ovc2/stable) at the home folder.

Typically, all you need to run is the ovc2_reconfigure script, which does the following:

• unloads modules which use PCIe
• loads the ovc2_cfg module, which creates a device node /dev/ovc2_cfg to expose a configuration interface to userland
• writes the FPGA configuration from userland to the /dev/ovc2_cfg device, which in turn uses the TX2 SPI interface to configure the FPGA
• loads the pcie_tegra module, which enumerates the PCIe bus and finds our newly-configured FPGA on it
• loads the ovc2_core module, which provides a userland driver for ovc2 on three device nodes: /dev/ovc2_core /dev/ovc2_cam /dev/ovc2_imu

For a typical software-development session, you typically just type ovc2_reconfigure and it's all automatic.

Then, you can run the ROS image streamer and feature-visualizer nodes:

Terminal 1:

roscore

Terminal 2:

cd ~/ros
source devel/setup.bash
rosrun ovc2 ovc2_node

Terminal 3:

rosrun ovc2 corner_viewer

I'm usually shelling into the camera, so "Terminal 1" and "Terminal 2" are remote shells on the camera, and "Terminal 3" is running locally on my workstation, setting ROS_MASTER_URI as needed to point to the camera (adjust the camera hostname as needed):

export ROS_MASTER_URI=http://ovc2a3.local:11311
rosrun ovc corner_viewer

Powering Down

For reasons unknown at the moment, if you try to power down the TX2 without first unloading the ovc2_core kernel module, the system will hang during the shutdown process, requiring you to then hold the TX2 power button down until the PMIC finally does a hard-shutdown.

If you run this script instead:

ovc2_poweroff

It will first unload the ovc2_core module and then run poweroff. It just saves one step to type ovc2_poweroff instead.