Tutorials > OpenIGTLink for Single-Board Computers

Introduction

A Single-Board Computer (SBC) is a small computer built on a single circuit board typically used as an embedded computer in hardware systems. Recently, hobby-oriented SBCs equipped with ARM-based processors have become popular and widely used for the hobby, educational, and research purposes. This page demonstrates how to develop and deploy an OpenIGTLink interface for ARM-based SBC using BeagleBone Black Wireless (BBB). The goal is to set up a cross-compile environment to compile and build the OpenIGTLink library (and application that uses the library) on a PC, and then execute the binary on the BBB hardware. (We setup the cross-compile environment for the demo purpose – It is still possible to build the OpenIGTLink library on BBB.)

Prerequisite

A host Linux PC for development (Ubuntu 18.04 was used for testing)
BeagleBone Black Wireless (BBB)

Connect BBB to Host PC

There are several ways to establish TCP/IP connection between BBB and the host PC, including Ethernet, WiFi, and USB. Please refer to Getting Started page.

Setup Cross-Compile Environment

To build a binary file for BBB (ARM-based) on the host PC (Intel-based), we set up a cross-compile environment using Linaro. Linaro provides binary cross-compile packages for Linux environments. Linaro can also be built using toolchain build scripts like crosstool-NG if you cannot find the right binary for the OS of your host PC (including macOS).

First, log in to your BBB using SSH (assuming that the IP for BBB is 192.168.7.2):

$ ssh -l debian 192.168.7.2

Debian GNU/Linux 8

BeagleBoard.org Debian Image 2016-11-06

Support/FAQ: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian

default username:password is [debian:temppwd]

debian@192.168.7.2's password: 
Last login: Sun Nov  6 15:34:01 2016 from 192.168.7.1
debian@beaglebone:~$ 

Then check the compile version of your BBB by:

debian@beaglebone:~$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-linux-gnueabihf/4.9/lto-wrapper
Target: arm-linux-gnueabihf
Configured with: ../src/configure -v --with-pkgversion='Debian 4.9.2-10' --with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.9 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libitm --disable-libquadmath --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-armhf/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-armhf --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-armhf --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-sjlj-exceptions --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb --enable-checking=release --build=arm-linux-gnueabihf --host=arm-linux-gnueabihf --target=arm-linux-gnueabihf
Thread model: posix
gcc version 4.9.2 (Debian 4.9.2-10) 
debian@beaglebone:~$ 

In the above example, the compiler version is 4.9.2. Once you find out the compiler version, download the binary package from the Linaro binary download page. Please make sure that the first two digits of the compiler version on your BBB (4.9) match the version number of the Linaro package. You can download directly from the web browser, or using wget:

$ wget -c https://releases.linaro.org/components/toolchain/binaries/4.9.4-2017.01/arm-linux-gnueabihf/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf.tar.xz

Finally, extract the files and copy them to the install folder:

$ tar xf gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf.tar.xz
$ mv gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf <install folder>

Build the OpenIGTLink library

We will build the OpenIGTLink library for (1) the host PC and (2) BBB.

First, obtain the code from GitHub:

$ git clone https://github.com/openigtlink/OpenIGTLink.git

Then create a build directory for the host, and build the library:

$ cd <working directory>
$ mkdir OpenIGTLink-build-x86
$ cd OpenIGTLink-build-x86
$ cmake -DBUILD_EXAMPLES=1 ../OpenIGTLink

Create a build directory for BBB:

$ cd <working directory>
$ mkdir OpenIGTLink-build-arm
$ cd OpenIGTLink-build-arm

To run a cross-compile from CMake, you need to make a toolchain file. Create a text file with the following contents and save it as “toolchain.cmake” in the build folder. Make sure to replace with the actual path you installed the cross compiler:

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR arm)

set(tools <install folder>/gcc-linaro-4.9.4-2017.01-x86_64_arm-linux-gnueabihf)
set(CMAKE_C_COMPILER ${tools}/bin/arm-linux-gnueabihf-gcc)
set(CMAKE_CXX_COMPILER ${tools}/bin/arm-linux-gnueabihf-g++)

set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

Finally, build the binary for BBB using the following commands:

$ cmake -DBUILD_EXAMPLES=1 -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake ../OpenIGTLink

Testing

Test the binaries by sending tracking data from the host PC to BBB.

Copy the binary file to BBB:

$ cd <working directory>/OpenIGTLink-build-arm
$ cd bin
$ scp ReceiveServer debian@192.168.7.2:

Open a second terminal and login to BBB:

$ ssh -l debian 192.168.7.2

Start the server:

$ ./ReceiveServer 18944

Go back to the original terminal and start TrackerClient. Make sure to use the binary for the host:

$ cd <working directory>/OpenIGTLink-build-x86
$ cd bin
$ ./TrackerClient 192.168.7.2 18944 10

You should see the received matrices on the second terminal if the binaries are working.

References

https://www.digikey.com/eewiki/display/linuxonarm/BeagleBone+Black