.Heindl Solutions - Setup HALCON 13.0 on a Raspberry Pi

Setup HALCON 13.0 on a Raspberry Pi

2018-03-06 by Andreas Heindl
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Today, we want to share our first screencast using Asciinema with you. The screencast is recorded on a per-character-basis directly from the Windows terminal. This allows you to copy'n'paste commands and output as needed, saves bandwidth and looks sharp and pretty.

Part 1: Setup a Raspberry Pi 3 from scratch

We assume you have bought a new Raspberry Pi 3 together with a Micro USB power supply (at last 2.1A) and a Micro SD card. We also assume that the Micro SD card is formatted as FAT32 and available as drive D: on an updated Windows 10 installation. Watch the screencast (explanations follow in the next section):

Details and explanations

  • Download NOOBS from https://www.raspberrypi.org/downloads/noobs/.

  • Unzip to Micro SD card (drive D:)

  • Automatically have SSH enabled directly after the Raspbian installation has finished by creating a file ssh in D:\

    echo . >D:\ssh

  • Make sure Raspbian OS will be installed automatically (disable prompting for other OS):

    • Remove other OS from SD card:
    rd /s /q D:\os\LibreELEC_RPi2
rd /s /q D:\os\LibreELEC_RPi
    • append silentinstall to the first (and only) line in D:\recovery.cmdline

  • Remove SD card, insert into Raspberry Pi, connect Ethernet and Power. Wait. Raspbian OS will be installed automatically. This took about 10minutes with our system.

  • While Raspbian installation is running, make sure that you have installed the Linux Subsystem for Windows to use SSH

    • as an alternative, install PuTTY and use pscp instead of scp and putty instead of ssh.

  • The Raspberry Pi will become available with hostname raspberrypi on the network.
    Default user: pi, Default password: raspberry .

Setup and test HALCON 13 on a Raspberry Pi 3 with Raspbian

Launch bash on the Linux Subsystem for Windows by typing bash in the Windows Start Menu (will match Bash On Ubuntu on Windows). Then:

Details and explanations

  • Copy HALCON (Linux) to your newly setup Raspberry Pi:

    scp halcon-13.0.1.1-linux.tar.gz pi@raspberrypi:/tmp

    • As this is your first connection to the Raspberry Pi, type yes to add raspberrypi to your list of known hosts.

    • Default user is: pi, Default password is: raspberry

  • SSH to raspberrypi:

    ssh pi@raspberrypi

  • Change default password for user pi:

    passwd

  • Unpack HALCON to /tmp/halcon:

    cd /tmp
mkdir halcon
tar xvf halcon-13.0.1.1-linux.tar.gz -C halcon

  • Install HALCON to /opt/halcon/halcon-13.0:

    cd /tmp/halcon
sudo ./install-linux.sh
    • During installation: Accept license, install to /opt/halcon/halcon-13.0, create target directory, choose Full (3) installation, install English documentation (1).

  • Remove temporary installation files:

    rm -r /tmp/halcon halcon-13.0.1.1-linux.tar.gz /tmp/halcon

  • Add a new command h13 to your .bashrc file. This allows to type h13 in the shell to setup your environment for HALCON 13.0:

    • Add this to your .bashrc

      function h13 {
    . /opt/halcon/halcon-13.0/.profile_halcon
}

    • Try:

    bash
h13

  • Enable license mechanism

    • Copy your license obtained from MVTec from the host computer (Windows 10) to the Raspberry Pi:

      scp license.dat pi@raspberrypi:/opt/halcon/halcon-13.0/license

    • attach your HALCON USB dongle

    • make sure the dongle appears as USB HID device (WIBU-SYSTEMS AG CodeMeter):

      dmesg | tail -n 10

    • copy udev rule for dongle and reload udev system:

      sudo cp /opt/halcon/halcon-13.0/misc/linux/udev/rules.d/59-halcon-codemeter.rules /etc/udev/rules.d
sudo udevadm trigger

  • Run hbench and hbench -parallel. Example output:

    pi@raspberrypi:~ $ hbench
HALCON 13.0.1 Benchmark (v13.0.1)
=================================
thread_num=1
(computing on images of size 1280x1024)

DATA_TYPE          reentrant
            time[ms]   value
byte ........  1.9e+03     0.7
int4 ........  860.563     0.7
float .......  2.4e+03     0.4
region ......  821.581     0.6
tuple .......   12.033     0.8

sum .........   6005.7     0.7
    pi@raspberrypi:~ $ hbench -parallel
HALCON 13.0.1 Benchmark (v13.0.1)
=================================
thread_num=4
(computing on images of size 1280x1024)

DATA_TYPE        parallel (4)
            time[ms]   value
byte ........  603.095     2.3
int4 ........  242.844     2.5
float .......  835.306     1.2
region ......  241.375     2.2
tuple .......    3.947     2.3

sum .........   1926.6     2.1

Write a simple C++ program that uses HALCON 13

We will write, compile, and run a simple and very basic HALCON C++ program. For demonstration only, it counts the number of pixels with gray values greater or equal 127 in the example image monkey.

Details and explanations

  • Create a C++ program in ~/halcon/hellorpi/main.cpp

    // main.cpp
#include <iostream>
#include "halconcpp/HalconCpp.h"

int main(int argc, char** argv) {
    (void)argc;
    (void)argv;
    HalconCpp::HImage image("monkey");
    HalconCpp::HRegion region;
    HalconCpp::Threshold(image,&region,127,255);

    // make sure to stream the tuple's integer value with .L()
    // otherwise, you would output the tuple in serialized format
    std::cout << "area: " << region.Area().L() << std::endl;
    return 0;
}

  • Compile with

    g++ -g -o hellorpi -I${HALCONROOT}/include -L${HALCONROOT}/lib/${HALCONARCH} \
  -lhalcon -lhalconcpp -Wl,-pthread -lm -ldl main.cpp

  • Execute:

    pi@raspberrypi:~/halcon/hellorpi $ ./hellorpi
area: 140422

Setup a Raspberry Pi Camera Module v2 for usage with Video4Linux2

TODO We will write, compile, and run a simple and very basic HALCON C++ program. For demonstration only, it counts the number of pixels with gray values greater or equal 127 in the example image monkey.

Details and explanations

  • Enable camera

    sudo raspi-config

    • In the graphical interface, go to 5 Interfacing Options then P1 Camera and then answer the question Would you like the camera interface to be enabled? with Yes.

    • Reboot

    • Check if camera is available:

      vcgencmd get_camera

    The output should be like supported=1 detected=1

    • Another test is to try to grab an image file: raspistill -w 2592 -h 1944 -o test.jpg If everything works, the command should return without any message.

  • Install V4L module

    • Try loading the module with

      sudo modprobe bcm2835-v4l2

    • If modprobe returns without errors, add the module permanently. At the end of file /etc/modules add the entry:

      # camera driver for v4l2
bcm2835-v4l2

    • Reboot

Execute HDevEngine script to process live images from the camera

HALCON 13.0 for armv7a-linux comes with a handy example program called hrun. We will compile it and execute a HDevEngine script to decode a ECC200 data code:

Details and explanations

  • Create a directory and copy the example program to it:

    mkdir ~/halcon/hrun
cd ~/halcon/hrun
cp -rp /opt/halcon/halcon-13.0/examples/armv7a-linux .

  • as we will compile directly on the Raspberry Pi 3 (in contrast to cross-compiling), we have to set the environment variable NATIVE to yes:

    export NATIVE=yes

    Attention: In the HALCON document HALCON for Arm-based Platforms they say you have to set it to YES. This is wrong, you have to use the lowercase writing yes.

  • Build hrun

    make

  • Execute hrun

    /bin/armv7a-linux/hrun

    This will show the command line help for hrun.

  • HALCON comes with the example script datacode.hdev to decode a ECC200 data code. It should output the decoded string together with the live images in a window, but the text output does not seem to work. Therefore, we will patch datacode.hdev to

    1. use live video images. Open datacode.hdev and change UseLiveImages from 0 to 1:

      <l>UseLiveImages := 1</l>

    2. output the decoded string to the console (stdout). As one of the first script lines add

      <l>open_file ('standard', 'output', STDOUT)</l>

    and add after the existing disp_message script line:

      <l>fwrite_string (STDOUT, DecodedDataStrings + '\n')</l>

  • Execute hrun with datacode.hdev

    If you are using a remote connection to the Raspberry Pi, make sure you have a SSH connection that supports X-Forwarding (ssh -X pi@raspberrypi) to open the live video image on your development machine. Then execute:

    ./bin/armv7a-linux/hrun datacode.hdev

    If you hold a ECC200 data code in front of the camera, it should be decoded and output to the console.

Questions?

If you have any questions regarding this topic or and other HALCON related questions please do not hesitate to contact us.