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Image Streamer

Table of contents

  1. Overview
  2. Requirements
    1. Hardware
    2. Target Software
    3. Host System
  3. Setup
    1. Camera Connections
    2. Target Software Setup
  4. Usage
  5. Network Configuration
  6. Stream with voxl-image-streamer
    1. Run Application On Target
    2. Run Application On Host

Overview

This user guide describes how to use the cameras with the voxl-cam-manager applications as a means to validate the camera connections. We’ll use an application on the VOXL to stream video to a desktop Python based application.

VOXL Cam Manager is included as part of the VOXL Software Bundle. The source code for this application as well as a desktop Python base GUI application is available here. Also, a Dockerized build environment is available here, so one could customize as needed.

Requirements

Hardware

  • Host computer (Ubuntu 18.04 used in this guide)
  • VOXL-DK
    • VOXL Core Board (MCCA-M0006)
    • Wi-Fi antennas (MANT-00001)
    • APM Regulator Board and cable (MCCA-M0009 and MCBL-00001 cable)
  • VOXL-ACC-PS
    • 5V/6A Power Supply (MPS-00001-1, MPN: WR9QA6000LCP-N(R6B)
  • VOXL-ACC-MV
    • Sunny GP161C Stereo Cameras and Flex Cable
    • Sunny MD102A Downward Facing Tracking (DFT) Camera and Flex Cable

Target Software

  • Cameras must be configured wtih voxl-configure-cameras. For more details refer to the quickstarts.

Host System

Host computer (Ubuntu 18.04 used in this user guide) with:

  • Python 2.7
  • Install the following packages
me@mylaptop:~$ sudo apt-get install python-dev
me@mylaptop:~$ sudo apt-get install python-qt4
  • Clone the following repo in order to fetch the image streamer python program.
me@mylaptop:~$ git clone https://gitlab.com/voxl-public/voxl-cam-manager.git

Setup

Camera Connections

The Machine Vision Accessory Kit (VOXL-ACC-MV) comes with the MD102A Tracking camera and flex cable and GP161C stereo cameras and flex cable.

  • Disconnect power
  • Connect the GP161C cameras and flex cable to J3 of the VOXL board as shown:
    • NOTE: when connecting the flex cable to J3, ensure the connectors are parallel when attaching and a solid ‘snap’ occurs to best ensure a good connection

camera-stream-0

  • Connect the MD102A camera and flex cable to J4 of the VOXL board as shown:
    • NOTE: again, when connecting the flex cable to J4 this time, ensure the connectors are parallel when attaching and a solid ‘snap’ occurs to best ensure a good connection

camera-stream-1

Target Software Setup

  • Connect power to VOXL
  • Connect the VOXL board via USB to the host computer
  • Make sure the VOXL Software bundle is installed
yocto:~$ cat /etc/modalai/voxl-software-bundle-version.txt

Usage

Network Configuration

  • Configure the VOXL as an Access Point (or connect it to a network)
    • instructions on how to do this are here
    • the default IP address of the device will be 192.168.8.1
  • Connect the host computer to the VOXL’s Access Point (default password is 1234567890) or to the same network you connected the VOXL to

Stream with voxl-image-streamer

Run Application On Target

/# voxl-image-streamer -h
usage: voxl-image-streamer -c [CAM_TYPE]... ARGS
   or: voxl-image-streamer -c [CAM_TYPE] -i [IP]... ARGS
-h                print this message.
-c [CAM_TYPE]     0=HIRES, 1=TRACKING, 2=STEREO
-i [IP]           IP address of the VOXL
-p [PORT]         port number to stream on, default 5556
-e [EXP]          set exposure; EXP between 0 and 1, default 0.36
-r [WIDTHxHEIGHT] image widthxheight, default 640x480
-g [GAIN]         set gain; GAIN between 0 and 1, default 0.35
-n [NUM]          stream every n-th image, default 1

Note, this chooses the camera IDs based on teh environment variables
set in /etc/modalai/camera_env.sh
Set up this file before use with the voxl-configure-cameras tool!

The -i ip address argument is optional. If omitted, the TCP stream
server will not start but the camera will still initialize.
Available resolutions are printed when the program starts.
Note, image_viewer.py currently does not show color.
  • For example, stream the stereo cameras using the following command:
yocto:~$ voxl-image-streamer -c 2 -n 4 -i 192.168.8.1

Run Application On Host

On the host computer, which is connected to the VOXL’s network, run the following:

me@mylaptop:~$ cd voxl-cam-manager/image_streamer/
me@mylaptop:~$ python image_viewer.py -i 192.168.8.1

The stereo camera video stream should display in a GUI.