ROS StartGuide

Introduction

ROS (Robot Operating System) provides libraries and tools to help
software developers create robot applications. It provides hardware
abstraction, device drivers, libraries, visualizers, message-passing,
package management, and more. ROS is licensed under an open source,
BSD license.

ROS Wiki

Wikipedia of ROS :

http://wiki.ros.org

ROS supporting versions

Currently, ROS distribution only supports installation on Ubuntu
linux, but there is meta-ros layer maintained under the
OpenEmbedded/Yocto framework, so we can integrate ROS into embedded
Linux that is also based on the Openembedded framework.

The OpenEmbedded build framework [1] provides a general cross-
compilation environment. This environment allows developers to set up
a tool chain for their application and to create a complete Linux
distribution for their embedded system. It supports various hardware
architectures and embedded boards through board support packages.

The meta-ros layer provides the recipes for ROS hydro, indigo and
kinetic. For the indigo distribution, it is currently the best
supported distribution in meta-ros. ROC-RK3308-CC are also integrating
this ROS distribution, and, it's root file system is based on the
yocto framework.

Reference firmware

Reference firmware:

ROC-RK3308-CC_Yocto_ROS

ROS Demo and it's operation manual can be referred to from

"User-instructions"

.

Ubuntu install of ROS Indigo

View all ROS

distribution release

. The latest ROS distribution, which is also the recommended version,
is ROS Melodic Morenia. There are more detailed installation
instructions in the official site. It should be noted that different
Ubuntu versions have different corresponding ROS distribution. For
example, ROS Melodic Morenia mainly supports Bionic (Ubuntu 18.04
LTS), while ROS Indigo Igloo supports Trusty (Ubuntu14.04 LTS) for
debian packages.

Since ROC-RK3308-CC are integrating the ROS Indigo Igloo distribution,
the PC should also

Install ROS Indigo Igoloo distribution

 for test, and the following simple installation instructions are also
** mainly designed for Ubuntu 14.04 (ROS Indigo)**. Installation
instructions for other distribution can be found on the

Official Website Wiki

.

Platform description

ROS Indigo only supports Saucy (13.10) and Trusty (14.04) for debian
packages.

Installation step

Configure your Ubuntu repositories

Configure your Ubuntu repositories to allow "restricted," "universe,"
and "multiverse." You can follow the Ubuntu guide for instructions on
doing this.

Setup your sources.list

Setup your computer to accept software from packages.ros.org.

   sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

You can also choose by yourself on the basis of

UbuntuMirrors

.

Set up your keys

   sudo apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key 421C365BD9FF1F717815A3895523BAEEB01FA116

Installation

1、Make sure your Debian package index is up-to-date:

   sudo apt-get update

2、Install:

We recommend Desktop-Full install: ROS, rqt, rviz, robot-generic
libraries, 2D/3D simulators and 2D/3D perception.

   sudo apt-get install ros-indigo-desktop-full

3、Initialize rosdep:

Before you can use ROS, you will need to initialize rosdep. rosdep
enables you to easily install system dependencies for source you want
to compile and is required to run some core components in ROS.

   sudo rosdep init
   rosdep update

4、Environment setup:

It's convenient if the ROS environment variables are automatically
added to your bash session every time a new shell is launched:

   echo "source /opt/ros/indigo/setup.bash" >> ~/.bashrc
   source ~/.bashrc

5、It is recommended to install rosinstall, a frequently used command-
line tool in ROS that is distributed separately:

   sudo apt-get install python-rosinstall

6、Test

Install the official

Tutorial

:

   sudo apt-get install ros-indigo-ros-tutorials

run a launch file of ros-tutorials:

   roslaunch roscpp_tutorials talker_listener.launch

If everything goes right, you will obtain the following result:

   SUMMARY
   ========

   PARAMETERS
    * /rosdistro: indigo
    * /rosversion: 1.11.21

   NODES
     /
       listener (roscpp_tutorials/listener)
       talker (roscpp_tutorials/talker)

   ROS_MASTER_URI=http://localhost:11311

   core service [/rosout] found
   process[listener-1]: started with pid [9520]
   process[talker-2]: started with pid [9521]
   [ INFO] [1545896255.189016471]: hello world 0
   [ INFO] [1545896255.289000624]: hello world 1
   [ INFO] [1545896255.388990355]: hello world 2
   [ INFO] [1545896255.489031727]: hello world 3
   [ INFO] [1545896255.489457481]: I heard: [hello world 3]
   [ INFO] [1545896255.589028597]: hello world 4
   [ INFO] [1545896255.589358894]: I heard: [hello world 4]

User Instructions

Next, we will introduce the operation of ROS by using a simple demo:
firefly_controller

This demo shows how to run ROS across multiple machines. It introduces
that all nodes must be configured to use the same master, via
ROS_MASTER_URI. This demo contents:

Switch the on/off of two LEDs on ROC-RK3308-CC mainboard by using PC
keyboard

Connecting to an external temperature & humidity sensor to obtain the
current temperature & humidity

The temperature & humidity sensor is SHT30, a sensor produced by
Sensirion based on i2c protocol. Its code was mainly based on

"ROC-RK3308-CC开发实例总结--SHT30温湿度模块调试"

。

ROC-RK3308-CC preparation

Burning firmware

Switch to loader mode according to

“burning_firmware”

, download the firmware from

ROC-RK3308-CC_Yocto_ROS

, unzip it and run these command:

   sudo upgrade_tool ul MiniLoaderAll.bin && \
   sudo upgrade_tool di -p parameter.txt && \
   sudo upgrade_tool di -uboot uboot.img && \
   sudo upgrade_tool di -trust trust.img && \
   sudo upgrade_tool di -boot zboot.img && \
   sudo upgrade_tool di -rootfs rootfs.img && sudo upgrade_tool rd

In accordance with the [getting_started] (http://wiki.t-firefly.com
/ROC-RK3308-CC/getting_started.html), power on the ROC-RK3308-CC
mainboard to start up and connect the serial port. Input the account
and password to enter the system terminal after powering on – the
account is "root" and the password is empty.

Note: If you have the SHT30 sensor, it should be connected to before
device powering on. It adopts I2C1 protocol for transmission and
"VCC5", "GND", "I2C1_SDA" and "I2C1_SCL" should be connected according
to

"Hardware Documents"

.

Initialize configuration

We prepared two scripts in the system for easy environment
configuration:

   ls /home/root
   setup.sh  wifi.sh

After starting up, wifi (WiFi should share the same network segment
with PC host so that it is possible to ping each other) should be
connected first. Please configure through script "wifi.sh" like
following,  where's "ssid" is your WiFi account and "psk" indicates
your password.

   ./wifi.sh $ssid $psk

Next, configure ROS environment as following. Since the PC host acts
as the master (the whole ROS operating environment only needs one
master), roscore will not be setuped.

   source ./setup.sh $master_ip

Of which, "master_ip" is the ip address of the PC host. We focused on
the configuration of "ROS_MASTER_URI" and "ROS_HOSTNAME" here and more
details can be found in setup.sh script.

Run demo's node

   rosrun firefly_controller firefly_controller

And waits until the PC host is prepared.

PC-host preparation

Note

: These instructions are for ROS Groovy and later. For ROS Fuerte and
earlier, select rosbuild.

Download Demo package

Download ROS Demo package at

firefly_iot_keyboard.tar.bz2

Create ROS work space

If you are installing ROS for the first time, it is possible to create
a ROS workspace through catkin:

   mkdir -p ~/catkin_ws/src
   cd ~/catkin_ws/src

This workspace can be compiled even it is empty (no software package
in the "src" directory, only a CMakeLists.txt link file).

   cd ~/catkin_ws/
   catkin_make

Compiling

First, unzip the Demo package to the "src" directory of the workspace:

   tar -xjf firefly_iot_keyboard.tar.bz2 -C ~/catkin_ws/src/

Then compile the workspace:

   cd ~/catkin_ws/
   catkin_make

Run

Open two terminals respectively and configure each one according to
the following steps.

Set the current workspace as the top level of ROS work environment:

   cd ~/catkin_ws/
   source devel/setup.bash

Set ROS_HOSTNAME as the host-ip, if not, the device cannot recognize.

   export ROS_HOSTNAME=$master_ip

One of the terminals starts the keyboard control node of demo:

   rosrun firefly_iot_keyboard keyboard.py

The other terminal starts demo receiving node:

   rosrun firefly_iot_keyboard receiver.py

Final effect

The result is as follows:

PC terminal

Note, if you cannot control,

please select the terminal window which running keyboard.py

 to ensure that your input can be captured.

Terminal of keyboard control:

   rosrun firefly_iot_keyboard keyboard.py

   Reading from the keyboard  and Publishing to firefly_controller!
   ----------------------------------------------------------------

   keymap:
       LED:
           b : Blue LED ON/OFF
           r : Red LED ON/OFF
       Sensor:
           t : show Temperature and Humidity

Press "r" and "b" of keyboard can switch to on/off of red and blue
LEDs respectively. If the SHT30 sensor is connected, press "t" can
obtain the temperature and humidity reported by the device, and such
data will be received by the terminal which is running the other node
"receiver.py".

Terminal of receiving:

   rosrun firefly_iot_keyboard receiver.py
    currently: 
     Temperature 28.607613c  Humidity 49.396507%

ROC-RK3308-CC result

Serial port print:

   root@rockchip-rk3308-evb:~# rosrun firefly_controller firefly_controller
   [ INFO] [1545900033.047350122]: I heard: [blue]
   [ INFO] [1545900034.086951914]: I heard: [red]
   [ INFO] [1545900035.106874956]: I heard: [sht30]

Debugging

Run "rosnode list" to display information about the ROS nodes that are
currently running:

   rosnode list 
   /firefly_base_controller
   /firefly_iot_keyboard
   /firefly_iot_receiver
   /rosout

It shows that three nodes of firefly_controller are running:
"/firefly_base_controller", "/firefly_iot_keyboard" and
"/firefly_iot_receiver"

Run "rostopic list" to return a list of all topics currently
subscribed to and published.:

   rostopic list 
   /cmd_vel
   /rosout
   /rosout_agg
   /temphumidity

It shows that firefly_controller has released two Topics:
"/temphumidity" and "/cmd_vel"

Run "rostopic echo" to show the data published on a topic:

   rostopic echo /temphumidity
   humidity: 50.0968933105
   temp: 24.1374816895
   ---
   humidity: 51.638053894
   temp: 23.3657588959
   ---

Use "rqt_graph" tool creates a dynamic graph of what's going on in the
system:

   rosrun rqt_graph rqt_graph


rqt_graph is part of the rqt package. Unless you already have it
installed, run:

   sudo apt-get install ros-indigo-rqt
   sudo apt-get install ros-indigo-rqt-common-plugins