Snapdragon Flight VISLAM-ROS Sample Code

This repository is a fork of the VISLAM from ATLFlight/ros-examples, modified to work with the px4 flight stack. The original README can be found in the ATLFlight/ros-examples repository.

Preparations

Mavros

Get the mavros sources into your catkin's source directory by following the instructions from the mavros git page. Last tested version of mavros is version 0.19 and the respective commit 399a04ef57.

This example code is for MV SDK release mv_1.0.2.

NOTE: The older release(mv0.9.1) instructions are here.

NOTE: Step 3 should also include --rosdistro kinetic flag.

Other packages

On a freshly flashed snapdragon, I had to install the following packages

python pip
python future (pip install future)
sudo apt-get install ros-indigo-diagnostic-updater ros-indigo-angles ros-indigo-eigen-conversions ros-indigo-urdf ros-indigo-tf ros-indigo-control-toolbox If control-toolbox cannot be installed due to unmet dependencies, you might have to install the missing dependency yourself. In my case overwriting an existing file was necessary for the package fontconfig-config. That can be done with sudo apt-get -o Dpkg::Options::="--force-overwrite" install fontconfig-config

Build

catkin build

Compiling mavros can easily take 30 minutes on the snapdragon. You might have to create a swap file when building catkin. Check this website on how to do that.

High-Level Block Diagram

Setup and build process

NOTE: These instructions are for VISLAM version mv_0.9.1_8x74.deb. For earlier versions refer to this page.

Summary of changes from previous release

Item	Previous release - mv0.8	Current Release - mv0.9.1	Future Release mv 1.0.2
MV_SDK environment variable	needed	Not needed. The new mv installation puts the library files under /usr/lib	Not needed
MV License file installation	needed. Should be placed in the /opt/qualcomm/mv/lib/mv/bin/lin/8x74/	needed should be placed at /usr/lib	needed should be placed at /opt/qcom-licenses/
MV link library Name	libmv.so	libmv1.so. Update the respective make files to link against libmv1 instead of libmv.so	same as mv 0.9.1

The current build process is supported only on-target (i.e. on the Snapdragon Flight^TM Board). Future release(s) will support off-target cross-compilation on a host computer.

The following is an overall workflow for installation, build and execution of the ROS sample apps for Snapdragon Flight^TM

Pre-requisites

Platform BSP

These instructions were tested with version Flight_3.1.3. The latest version of the software can be downloaded from here and installed by following the instructions found here

NOTE: By default the HOME environment variable is not set. Set this up doing the following:

adb shell
chmod +rw /home/linaro
echo "export HOME=/home/linaro/" >> /home/linaro/.bashrc

If you use SSH, the home environment variable should be set correct after the above step. If you use ADB, do the following for each session:

adb shell
source /home/linaro/.bashrc

Install ROS on Snapdragon Platform.

Refer to the following page for ROS installation on Snapdragon Flight^TM platform.

Install Snapdragon Machine Vision SDK

Download the latest Snapdragon Machine Vision SDK from here
The package name will be mv<version>.deb.
** Example: mv1.0.2_8x74.deb
push the deb package to the target and install it.

adb push mv<version>.deb /home/linaro
adb shell sync
adb shell
dpkg -i /home/linaro/mv<version>.deb

NOTE: MV release 0.8 and earlier required to set the MV_SDK environment variable. This is no longer needed. Make sure to unset this variable if it is set. Not doing so will give an compilation error that says, "mv.h" file is not found.

Machine Vision SDK License Installation

The Machine Vision SDK will need a license file to run. Obtain a research and development license file from here

The license file needs to be placed in the following folder on target: /opt/qcom-licenses/

Push the license file to the target using the following command:

adb push snapdragon-flight-license.bin /opt/qcom-licenses/
adb shell sync

NOTE: Make sure to create the folder /opt/qcom-licenses/ if it is not present on the target.

Clone and build sample code

Setup ROS workspace on target

adb shell
source /home/linaro/.bashrc
mkdir -p /home/linaro/ros_ws/src
cd /home/linaro/ros_ws/src
catkin_init_workspace
cd ../
catkin_make
echo "source /home/linaro/ros_ws/devel/setup.bash" >> /home/linaro/.bashrc

This ensures that the ROS workspace is setup correctly.

Clone the sample code

The repo may be cloned directly on the target (catkin workspace), or cloned on the host computer and then pushed to the target using ADB. The recommended method is to clone directly on the target.
Build the code

Configure

Copy the px4 configuration files from ./px4_configs to their respective location on the snapdragon. For using the recommended EKF2:

cd snapdragon_mavros_vislam
adb push ./px4_confs/ekf2/mainapp.conf /home/linaro/mainapp_vislam.conf

The configurations are intended to provide a working starting point. Adjust parameters to your likings.

Run

In a terminal, launch mavros and vislam

adb shell
roslaunch snapdragon_mavros_vislam mavros_vislam.launch

Start the px4 flight stack

adb shell
cd $HOME
./px4 mainapp_vislam.config

saimouli/px4VIO