FloSystem

This is the the master repository for all of the Lil'Flo remote control, local control, messaging, etc.

In this README you will find everything you need to work with and develop on the Lil'Flo platform.

You may be interested in papers and posters on the project

License:

MIT License. Have fun!

Copyright 2021 University of Pennsylvania, Rehabilitation Robotics Lab

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Contents

• WebServer Setup
• Development Computer Setup
• Network Setup
• NUC Setup
  • UDEV for USB fixed Addresses
  • USB Speker
  • Realsense Cameras
• Amazon Polly Setup
• WebRTC ROS Setup
• Developing on The System
  • Simulator
• Running Code
• Things That May Break
  • The Web Interface Doesn't Respond
  • Packages are missing
  • Services Don't Exist
  • Realsense has version mismatches
  • ROS won't build
  • No audio plays
  • No videos on web
• [Camera Recalibration]
  • [Practical Tips]
  • [Realsense Tools]
  • [OpenCV]

WebServer Setup

Setting up the webserver is a totally different issue from setting up the robot. Everything runs in docker. Let's walk through real quickly what is going on: When anything outside hits the webserver stack, they are going to route through Nginx, which is listening on both ports 80 and 443. The definition for Nginx depends on the environment, production or development, and is defined in flo_web/nginx-prod.conf and flo_web/nginx-dev.conf respectively. In production, Nginx will serve the static front end files itself. In development create-react-app (via nodejs) will serve them so that the developer has hot reloading. The Nginx docker image is defined in flo_web/Dockerfile where the front end is first compiled and then added into Nginx.

When in development, the create-react-app runtime is defined in flo_web/web_app/Dockerfile.

For both production and development, the backend socket server runtime is defined in flo_web/web_server/Dockerfile.

There is a base docker-compose file in the root. This file defines the operations during production. There is also a docker-compose override file, which defines operations during development. This is done by changing the commands which run in the docker images, changing what volumes are mapped to bring in code and config files, and adding in the front end server.

Server Config Files

You should create a file in FloSystem/certs/session-secret.env with contents: SESSION_SECRET=<cryptographically random value ex:random string of characters or numbers>

You should create a file in FloSystem/certs/coturn.env with contents:

COTURN_SECRET=<cryptographically random value>
SITE_ADDR=<the site address, ex: lilflo.com>

You should create a file in FloSystem/certs/datadog.env with contents:

DD_API_KEY=<cryptographically random value>
DD_HOSTNAME=<hostname ex: lilflo.com>

SSL certs

Local

We need ssl certs during local development.

1. sudo apt install libnss3-tools
2. Download the latest binary for mkcert Then install mkcert using installation guide on the github
3. Change permissions sudo chmod u+x <name of binary ex:mkcert>
4. Setup certs registry: <name of binary: mkcert...> -install
5. Make a certs dir/folder (named certs) in the root of this repo and go into it
6. Make new certs: <name of binary: mkcert...> localhost you can add other options here if you want to simulate a local domain by putting it in your hosts file, add in the 127.0.0.1 or other localhost aliases, etc. You can even use wildcards. NOTE: be very careful with these, they can really really open you up to security holes in your local computer if shared.
7. rename the certs: mv localhost-key.pem localhost.key && mv localhost.pem localhost.crt Of course if your certs are named something else... you get the idea.

Server

We use certbot to generate certificates automatically. The certbot certificates automatically. They expire every so often, so they need to be regularly regenerated. We have it run once a week on sunday at 2:30AM eastern to regen certs and 3:30AM eastern to restart the server and use the new certs. The whole system runs based on a guide

Setting up first admin

When you initially create the system, you will have no users. You can register a new user, but that user will not have administrator privelages. You need to setup a first admin. To do this:

1. Create a user account by registering through the web interface
2. Attach to the docker image for the postgres database into pg: docker container exec -it flosystem-postgres_1 psql flodb -h localhost -U postgres (note the number on that container might be different...)
3. Turn on expanded view to get nice prints: \x
4. Optionally get info on your registered users: select * from users;
5. Find out what id admin users need: select * from user_types;
6. Set the user you are interested in to be an admin: update users set user_type=<id of usertype you want> where email=<email you want>;. Ex: update users set user_type=1 where email='testsobrep@seas.upenn.edu';
7. Check that it worked: select * from users;

Deploying to Linode

Linode is small, easy to use, and affordable.

1. Setup a node on linode. The small size should be fine. When setting up, setup an ssh-key to make your life easier. Use the latest Ubuntu LTS.
2. Setup the A/AAA record to work with your domain name and have your register use the linode domain servers.
3. Install and setup firewall:
   1. apt install ufw
   2. ufw default allow outgoing
   3. ufw default deny incoming
   4. ufw allow ssh
   5. ufw allow http
   6. ufw allow https
   7. ufw enable
   8. Check status with ufw status
4. Setup unattended updates: apt install unattended-upgrades
5. Clone this repository
6. update and upgrade: apt update -y && apt upgrade -y
7. Install docker
8. Install docker-compose: apt install docker-compose
9. Go into the repo root and run docker-compose -f docker-compose.yml -f docker-compose.prod.yml build
10. Run docker pull certbot/certbot
11. Setup certificates by running ./init-letsencrypt.sh
12. Run docker-compose -f docker-compose.yml -f docker-compose.prod.yml up -d
13. Monitor with docker ps, docker stats, and docker-compose logs -f
14. If you need to take it down, run: docker-compose down

Deploying TURN Server

In some network situations, you will need a turn server. In those cases, you probably want to be running UDP, TCP, and TLS on port 443 to allow packets through.

After trying to get this to work behind Nginx to get this all on one server, I have concluded that the turn server should be on an independent vm. This makes the port management easier and prevents the turn server from taking resources from the rest of the system.

1. Create a new Ubuntu 18 vm.
2. Create an A/AAA record for turn.<url>
3. Install and setup firewall:
   1. apt install ufw
   2. ufw default allow outgoing
   3. ufw default deny incoming
   4. ufw allow ssh
   5. ufw allow http
   6. ufw allow https
   7. ufw allow 80/udp
   8. ufw allow 443/udp
   9. ufw allow 49152:65535/udp
   10. ufw allow 49152:65535/tcp
   11. ufw enable
   12. Check status with ufw status
4. Setup unattended updates: apt install unattended-upgrades
5. Clone this repo
6. update and upgrade: apt update -y && apt upgrade -y
7. Install docker
8. Install docker-compose: apt install docker-compose
9. Go into the repo root and run docker-compose -f docker-compose-turn.yml build
10. Run docker pull certbot/certbot
11. Setup certificates by running ./init-letsencrypt-turn.sh
12. Run docker-compose -f docker-compose-turn.yml up -d
13. Monitor with docker ps, docker stats, and docker-compose logs -f

Robot

Throughout this setup, we will assume that you are using a clean install of the version of linux that is called for. The setup may not tolerate weird tweaks to the python version, will not work with conda, and will not work with python virtual environments.

The first think to do is to setup your development computer:

Dev Computer

You will need to have a development and control computer. At the least you will need to follow the instructions in the Network section. If you want to actually be writing new code and devloping, you will need all of this:

1. Setup Ubuntu, either 16 or 18
2. Install git: sudo apt intall git-all
3. Clone this repo into ~/Documents/git
4. Run ./dev_install.sh
5. Setup your bashrc or zshrc to have ros stuff. There an example loader that you can take a look at.
6. If you are going to be testing the text to speech system on your development computer, then you need to follow the Amazon Polly Instructions
7. Node, is needed to develop and run the websever. You can install directly (better for the robot) using node_install.sh or with nvm (better for development) using nvm_install.sh. If you are working with the web server, you will also need to install
8. You will need to setup the network

Example Loader

Note this was written to run in zsh, there are places where bash may want a semicolon, but really, why are you using bash?:

This will set the ROS and OS version and also setup a function to get the ip address of this macine on different NICs. This should run without problems

if (($(cat /etc/os-release | grep VERSION_ID|grep -o '".*"' | sed 's/"//g' | cut -c1-2 )==16));then
    ROS_VERSION="kinetic"
    OS_VERSION="xenial"
    function ifip { /sbin/ifconfig $1 | grep "inet addr" | awk -F: '{print $2}' |awk '{print $1}'; }
    else
    if (($(cat /etc/os-release | grep VERSION_ID|grep -o '".*"' | sed 's/"//g' | cut -c1-2 )==18)); then
    ROS_VERSION="melodic"
    OS_VERSION="bionic"
    function ifip { ip -4 addr show $1 | grep -oP '(?<=inet\s)\d+(\.\d+){3}' }
fi
fi

You then need the code to actually connect to the robot:

function connect_to_robot {
    echo "setting up for $1"
    echo "using ros version: $ROS_VERSION"
    echo "on OS: $OS_VERSION"
    source /opt/ros/${ROS_VERSION}/setup.zsh
    source ~/catkin_ws/devel/setup.zsh

    case $(hostname) in
        linPower)
            echo "recognized device Lin Power"
            export ROS_IP=`ifip enp0s31f6`;;
        x220t)
            echo "recognized device x220t"
            export ROS_IP=`ifip wlp3s0`;;
        mjs-mws)
            echo "recognized device MJS-MWS"
            export ROS_IP=`ifip enx98e743e78ee0 || ifip wlp59s0`;;
        *)
            echo "unknown system";
    esac
    # Handle the device not existing and getting something empty:
    [  -z "$ROS_IP" ] && (echo "ROS_IP unset, setting on loopback"; export ROS_IP=`ifip lo`)

    # takes a single number arg representing the robot
    if [ "$1" = "flo" ]
    then
        export ROS_MASTER_URI=http://flo-nuc:11311
        echo "added nuc as master uri"
    elif [ "$1" = "kq" ]
    then
        export ROS_MASTER_URI=http://192.168.1.24:11311
        echo "added kendal's computer as master uri"
    elif (( $1 == 0 ))
    then
        export ROS_MASTER_URI=http://localhost:11311
        echo "connected to local machine"
    fi
    echo "set ROS MASTER URI to $ROS_MASTER_URI"
    echo "set ROS IP to $ROS_IP"
    echo "done setting up ros"
}

So now, when you run connect_to_robot xyz in the terminal:

1. all of the necessary ROS files will be sourced
2. based on the computer you are on, the correct NIC will be used to get the IP address.
   1. Note that for mjs-mws, there are two NICs of interest, that are ordered by priority. This allows us to use a wired network if available and if not to fall back to the wireless.
   2. If there is no IP address, ie. your not connected to a network, then the loopback device will be used.
3. Based on the input given, the ros master will be set to connect to a specific robot.
   1. For zero, the local machine will be connected to.
   2. Other options are flo, kq, x220t. You probably don't need all of these, but it gives you a nice template of how to work.

Some things to keep in mind:

• You need to adjust the hostnames section. You should use the host name of your computer and the network adapter you want. You can find the names of your network adapter by typing either ifconfig or ip a in the terminal
• You will likely need to add a different robot. You can simply use the ones that are above as a template. You will need your common language name for the robot and its IP address.
• connect_to_robot 0 will connect to your local robot

SSH-Keys, Hosts List, and SSHing in

You will now need to setup SSH Keys. Just follow this guide

You will probably also want to add the flo robot to your hosts list to make life easier. To do that: edit your hosts file: sudo nvim /etc/hosts to have the nuc listed. Add this: 10.42.0.189 flo-nuc

You can also create a function in your bashrc that allows easier sshing in:

function ssh-flo {
    ssh nuc-admin@flo-nuc
}

NUC

1. Setup Ubuntu
   1. Make sure to connect to a network and update everything
      • When connecting to the network, you should obscure your password. To do this, run wpa_passphrase [ssid-name][password-name] and use the result for the network. Set the password to only save for this user (little logo at the end of the password line)
   2. Make sure to set the system to login automatically
   3. enable ssh: sudo apt install openssh-server
2. Use lsyncd with the configuration file (See Developing) to copy files over
3. ssh into the robot and run the install script (bash ./robot_install.sh).
   • It may ask you to set up a secure book key. Make sure that on the next reboot you select install key and enter your password. If you fail to set up properly, attached hardware will fail. Fix this by running sudo update-secureboot-policy --enroll-key
4. You need to setup read/write privileges for all of the USB devices and setup fixed addresses using udev
5. The speaker may need to be setup a bit different
6. Settings and firmware will need to be updated on the realsense cameras
7. You need to setup Amazon Polly This should be as easy as just answering the questions during the install script.
8. You will need to setup the webrtc ros code. This is now ahndled by a script as part of the install.
9. Add to the bashrc file on the robot:
   • export ROBOT_NAME=<robots name> The name should be the unique name of the robot. The current valid values are lilflo and mantaro, as we add more systems, each name must be unique
   • export ROBOT_PASSWORD=<robot password> This is the password generated by the webserver
   • export FLO_SERVER_IP=< wherever the server is. Ex: "lilflo.com"> Which will allow the system to point to the webserver. During development you might have a different value here...
   • If you are working with a server that doesn't have real certs (this should only be true for development on a local machine). THen you also need to tell the router to not check certs by adding to the bashrc: export NODE_TLS_REJECT_UNAUTHORIZED='0'
10. Add two cron jobs to automatically startup the system:
    1. crontab -e
    2. SHELL=/bin/bash This will set the shell that things should run in
    3. @reboot (sleep 90; source ~/.bashrc; ~/catkin_ws/src/FloSystem/robot_tmux_launcher.sh)
    4. */1 * * * * (source ~/.bashrc; python ~/catkin_ws/src/FloSystem/flo_web/pinger/pinger.py)
11. Setup firewall (really need that with ros)
    1. sudo ufw default allow outgoing
    2. sudo ufw default deny incoming
    3. sudo ufw allow ssh
    4. sudo ufw enable
    5. check: sudo ufw status
12. Take a look at the bash_includes file. It should be going in through the install system automatically. Might not be though. For testing you want to set the ros_ip. But for deployment you do not. If a ROS IP is set using a network which the robot is connected to, then upon network loss the ros system will crash

Assigning the serial devices to have a fixed addresses {#udev}

Setup UDEV Rules to make the face always have the same name:

1. Run `python -m serial.tools.list_ports` to see which ports
   are connected. Then plug in the device and run it again,
   the new port is the one which you are connected to
2. Run `udevadm info --name=/dev/ttyACM0 --attribute-walk`
   with the name matching the port which you found in the
   previous step. Find the device with manufacturer
   . Note the idVendor, id Product, and serial
   number.
3. Edit file `/etc/udev/rules.d/99-usb-serial.rules` (create if
   necessary) to have:
   `SUBSYSTEM=="tty", ATTRS{idVendor}=="XXXX", ATTRS{idProduct}=="XXXX", ATTRS{serial}=="XXXXXXX", SYMLINK+="flo_face", MODE="0666"`

    `SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", SYMLINK+="bolide"`

4. Load the rules: `sudo udevadm trigger`
5. You can check that it worked by running: `ls -l /dev/flo_face`

The naming scheme ends up like this:

SUBSYSTEM=="tty", ATTRS{idVendor}=="16c0", ATTRS{idProduct}=="0483", ATTRS{serial}=="1582410", SYMLINK+="flo_face", MODE="0666"
SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", ATTRS{serial}=="A104D4GV", SYMLINK+="bolide", MODE="0666"
SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", ATTRS{serial}=="kobuki_A907BUO2", SYMLINK+="kobuki", MODE="0666"

If this is working correctly then the mode should be 666 to allow read/write privileges. If it isn't working and getting a no access error, then you will need to run chmod 666 /dev/XXXX. Then figure out what is wrong and fix it...

USB Speaker

I am not sure if this is needed:

You may need to make the usb speaker the default device: sudo vim /usr/share/alsa/alsa.conf

change:

defaults.ctl.card 0
defaults.pcm.card 0

to:

defaults.ctl.card 1
defaults.pcm.card 1

then restart

Realsense Cameras

The realsense cameras seem to hold a lot of settings on board. For now, you need to plugin the camera and run realsense-viewer. For now, set the system to high accuracy with the laser projector set to laser.

Amazon Polly

Polly will need to have access to AWS to work. To set that up, go to the IAM Console and click on users. Then select the user you want to give access to. Click "Create access key" under Security Credentials. Then in the console on the computer run ./aws_install.sh which will install the AWS CLI for you and run aws configure --profile flo, it will prompt you for input an you should fill in the info from the IAM console with region set to us-east-1 and output set to json.

A few notes:

• you should probably restrict what the user that is getting access can do. The best option is to set the permissions to AmazonPollyReadOnlyAccess
• You can have other users configured. By changing the --profile, you control the name of the user if no profile is specified, then the information is saved to a default
• If you ever need to revoke permissions for a user, that can be done from the IAM Console by deactivating the user's Access Keys.
• TODO: I would like to find a way to limit how many calls can be made by a user.
• To check whether polly is available given the profile, run aws polly help --profile flo. If you get back a list of commands to run on polly, you should be good.
• To fully test, can run: aws polly synthesize-speech --output-format mp3 --voice-id Ivy --text 'hello, this is a test' --profile flo test.mp3 and then play the audio by installing: sudo apt install mpg123 and typing mpg123 test.mp3
• you might find that you are getting some sort of server connection errors. you can resolve that by running pip3 install -U boto3 (this should now be a part of the install script, but it is commented out)

Developing

When developing, all code changes should be made on the development computer. Nothing should be getting changed on the robot. Instead code changes should be made on the development computer and synced over. This allows multiple users to work with the robot without login issues or anything of that nature while keeping everything under source control.

To achieve this, we use lsyncd, which automatically pushes code changes to the robot when running. Take a look at templateSyncConfig.lua to learn how to sync your work over to the robot.

Simulator

For developing anywhere, the best thing to do is to use the docker stack of simulators.

If you are on a computer with the realsense cameras plugged in and you can install the entire stack locally, then you can run sim_tmux_launcher.sh. This will run the entire Lil'Flo system in simulation and run the web servers for you. For this to work, you will need to setup the config files and keys needed by the webserver

If you are on a machine that does not have the entire stack installed, then you can run an entire simulation stack within docker. To do this:

1. Follow the instructions for setting up ssl certs

2. Follow instructions for setting up config files

3. Install docker and complete the post installation steps, then test docker by running the hello world image

4. Run docker-compose up

5. Open Chrome and navigate to localhost

6. Follow instructions to setup admin

7. Login with your new admin account, go into the admin portal, click add robot, give the robot a name and type of lilflo and before submiting copy the password to clipboard and save it. Then hit submit.

8. Make a file ./certs/sim-info.env with ROBOT_NAME=<name from web interfave> and ROBOT_PASSWORD=<password from web interface>

9. Make a file ./certs/aws-credentials and populate it with a valid AWS credential which has access to aws polly. The first line should have [flo] the second line should have aws_access_key_id = <the access key id> the third line should have aws_secret_access_key = <secret key>. You also need to create ./certs/aws-config and pupulate that with valid AWS config. First line should be [profile flo] second line should be the region, ex: region = us-east-1 third line should be the output output = json

10. Run ./docker_sim_launcher.sh. This file can be passed -r to rebuild the underlying docker images for the robot if you have changed code

11. Go to localhost

12. To inspect the system, in an unused terminal: docker exec -it <container name, ex: flosystem_flo_sim_1> /ros_entrypoint.sh bash

13. After entering localhost Add the newly created robot to your profile under admin portal and enter the email used to setup your account to add the robot to your profile.

Note: This will mount your local code, so you don't have to shut the entire system down for every code change. For the web frontend, code will reload automatically on save (sometimes you need to save twice). For python files running on the robot, you can simply kill the affected node(s) using your docker exec access terminal (described above) and when they restart they will have your new code. To reset docker (i.e., to remove all unused containers, networks, images (both dangling and unreferenced), and optionally, volumes)), run docker system prune -a.

Simulating Podium

You can also run a simulator of the podium. Simply run ./docker_sim_launcher.sh -p. You do not need the webserver running. The podium screen with simulated images should just show up.

Running

If fully set up as described above, then when the robot powers on, it will automatically start all of the software after a short delay, connect to the server, and be ready to use. If that has not been done, then:

1. ssh into the robot: ssh nuc-admin@<ip addr>
2. Run the tmux launch script: ./robot_tmux_launcher.sh
3. Attach to tmux: tmux a

When in tmux, you navigate between windows with ctrl+b + w + arrow keys. You navigate between panes with ctrl+b + arrow keys. To leave tmux, just progressively close programs with ctrl+c and type exit and they you can close them as you go.

You can then launch your web browser and navigate to http://10.42.0.189:3000/ to see the web interface. You can also always use rviz and the other ROS tools to make this all work on your local computer.

Some useful tools:

For monitoring the kobuki, you can use the kobuki dashboard. Run: rqt -s kobuki_dashboard.

Getting Data off the Robot:

Once the robot has been used, you will need to get data off of it. There are a few options for this:

• Transfer to external media, this is easy and fast, SSH into the robot, plug storage into the front USB3 ports, and use the mv (move) or cp (copy) commands to move things to the usb drive. You should be able to find your USB drive in the /media/nuc-admin folder. The cp command does not provide feedback, an alternative is to use rsync: rsync -ah --progress <source> <destination>
• Use SCP, this is a pain, not at all worth it
• Use an FTP gui, this works quite well but is limited by network speed, in your FTP gui, set the address as ftp://flo-nuc and then copy the data over the network.

All of the data should be stored in the /home/nuc-admin/flo_data folder. There will be two types of files, rosbag files, 1 per minute of operation, and parameter dumps, one from startup and one from shutdown.

Things that may break: {#break}

The web interface just doesn't do anything {#broken-web}

check to see if the socket is just closing imediately. If it is, then it may be that the version of tornado on the server is wrong. Uninstall the version from pip, then uninstall the version from apt, then reinstall the rosbridge suite.

Packages are missing {#missing-packages}

It probably means you added dependencies since installing. Most dependencies are installed via rosdep by running:

sudo apt update -y && sudo apt upgrade -y
rosdep update
rosdep install --from-paths ~/catkin_ws/src/FloSystem/ --ignore-src -r -y

Some dependencies can't be installed by rosdep and should be installed by the install scripts. In that case, you should look at the most recent commits into git for the install scripts and try to figure out which commands need to be run. You could also just try to re-run the install scripts.

You might also be missing packages missing in the web server. Just navigate to the web app folder (flo_web/web_app) and run npm install.

Weird stuff says services don't exist {#broken-services}

Try running catkin_make on the catkin ws. If that doesn't work well, also delete the install and dev folders in catkin_ws and run catkin_make

REALSENSE has version mismatches and stuff {#broken-realsense}

PAUSE!! Ok, Realsense is a pain. Intel really doesn't want us using their hardware. The first thing to do is to go check the latest releases from realsense-ros. What version of librealsense is supported? You probably want to update to the latest version of realsense ros but only want to upgrade to the version of librealsense that that supports (wtf intel?). Good luck my friend

apt update and upgrade Go into catkin_ws/src/realsense-ros run:

git fetch
git checkout `git tag | sort -V | grep -P "^\d+\.\d+\.\d+" | tail -1`

cd up to catkin_ws and run:

catkin_make clean
catkin_make -DCATKIN_ENABLE_TESTING=False -DCMAKE_BUILD_TYPE=Release
catkin_make install

It is also possible that you need to update the camera's firmware. To do this, open realsense-viewer with the camera connected to a computer with an available GUI. You will be prompted to update the firmware.

Stuff just won't build {#broken-build}

All kinds of things could cause this. The first thing to try it to clean the build and reinstall it:

cd ~/catkin_ws
catkin_make clean
catkin_make
catkin_make install

There is no audio playing {#broken-audio}

The first thing to do is test the speaker by running speaker-test Then hop into Alsa Mixer alsamixer, press F6 and select the USB Device, but this can only change the volume. It is also possible that the wrong audio device is selected. To fix that, you will need to select the audio device. List the available devics by: pacmd list-sinks|grep index and then set the one you want with pacmd set-default-sink <sink_name|index> You can also set the volume here.

Videos don't show up when running {#broken-web-video}

There are a few possible problems:

1. things only seem to work in chrome for now, so use that.
2. You may not have your devices enabled because the source is non-secure. Here is what to do: a. goto: chrome://flags/#unsafely-treat-insecure-origin-as-secure b. fill in with: http://10.42.0.189:3000,http://10.42.0.189:9090,http://10.42.0.189:9091 c. change to enabled

#Recalibrating the Realsense

Practical tips

1. The Intel D415 has the following parameters:

   • Intrinsic : Focal length, Distortion and Principal Point for each of the three cameras.
   • Extrinsic : baseline, RotationLeftRight, TranslationLeftRight, RotationLeftColor, TranslationLeftColor

2. The camera might be out of calibration if flat surfaces look noisy/wobbly, depth images have many holes, physical distances are not within 3% of the expected distance. This might happen if the camera falls down/the factory calibration changes due to some other event which in not very frequent.

##Using Realsense Tools

1. On chip self calibration can be performed using the Realsense Viewer(comes with Intel® RealSense™ SDK 2.0). This tool provides a health-check of current calibration. If the value is below 0.25, the calibration is good. Anything above 0.75 needs recalibration. The intrinsics and extrincs can be calibrated by pointing the camera at a flat white wall in good lighthing condition. The application also scores and allows comparison of new calibrations. For more: https://dev.intelrealsense.com/docs/self-calibration-for-depth-cameras

2. Extrinsic calibration using Intel Realsense Dynamic Calibrator(https://dev.intelrealsense.com/docs/intel-realsensetm-d400-series-calibration-tools-user-guide). The guide provides instruction for downloading the Dynamic Calibrator app. Targets and Demos can also be found at the same link.

##Using external tools

One way to check calibration is to print checkerboard targets(https://boofcv.org/index.php?title=Camera_Calibration_Targets). Then use: https://github.com/IRIM-Technology-Transition-Lab/camera-calibration , or equivalent to compare current parameter values with those returned from the calibration program.