ROS and Raspberry Pi for Beginners | Tutorial #0 - Topics Packages RosMaster

[@prandtlmayer]

Don't miss the other videos of the ROS Series: kzbin.info/www/bejne/hGeuY3-NfJeeiKs

[@nothanks7752]

oh thank god. I'm going through a ROS tutorial on skillshare, and the guy spent half an hour explaining what you covered in the first 3 minutes.

[@prandtlmayer]

I love your comment. But it's hard to create the perfect tutorial. You can never please everyone. Follow the series and feel free to contribute with your suggestions

[@nothanks7752]

@@prandtlmayer It's just something that I'm noticing a lot with skillshare classes. The instructor will drag out the "setup" instruction, also splitting it into multiple videos, so first glance at their class is "200 videos, 15hrs of content", but everything is drug out and inflated with marginally better content than free youtube tutorials.

[@noicthebrave]

Thank you so much - because of this video, I was able to get my car up and running in no-time! While there's still some kinks on my end, just getting the thing working @ all was quite a task. Much Appreciated! TY! Edit: For those of you wondering, yes, simply buying the PWM board VS trying to make a work-around is definitely worth the price point. I personally got 2 of them from Amazon for ~$13-15 USD, definitely made the lower-level set-up process of this project go a lot smoother and allowed me to move onto higher-level things faster. (Thak you again for this video :) )

[@prandtlmayer]

I know guys that for a beginner the video is a little too fast. The purpose was to get things ready and have a general flavor of what's the series about. In the next video we'll go back to the main concepts and introduce a few more tools.

[@mfatihozkan3503]

Hello Mr. Tiziano. I am trying to use rpi camera with ros melodic. How can i use kinetic packages with melodic. Can you help me ?

[@ozcankosar5416]

My car has a hard time going backwards. where do i change the values?

[@prandtlmayer]

Usually you need to command back for the break and back again for actually backing out

[@noeljohney6538]

Thank you Tiziano for this video. I am using this video as a reference for studying ROS for the past 8 months almost every weekend. There is a lot of content in this video which was explained in just 18 minutes.

[@prandtlmayer]

A lot to absorb, I know. Hope this gives you a hint of how powerful of a tool ROS is

[@saviopullkotil2270]

Hello, great explaination! I had a doubt, in my robot car i want to control the 4 dc motors (2 on each side) and there is no servo. We want to use a differential drive kind of motion to take a turn so how should i change the processes here?

[@adarshgouda847]

Great work with this video... keep up the good work... i'm watching this at 0.25 playback speed and still its hard to pause and catchup... would greatly appreciate it you could drop the pace in your future tutorials... again... great work!

[@KanagachidambaresanGR]

Hi.,. please post tutorial for robo car control with rp-lidar

[@ozcankosar5416]

everytime i try to download a package. E: Package 'samba' has no installation candidate . i get the error

[@prandtlmayer]

And that is for the raspberry pi?

[@ozcankosar5416]

@@prandtlmayer yes

[@sumitk2521]

5:20 I got 2 errors while doing catkin_make i2c/smbus.h no directory , invoking "make j-2" failed

[@jcmay]

i have the same problem

[@sumitk2521]

@@jcmay that package has some issues I downloaded different package

[@jcmay]

thanks @@sumitk2521 I will try another tutorial

[@prandtlmayer]

That i2c driver is problematic for some.

[@shantanuparab2280]

I am unable to build the i2cpwmboard package. The error shows some files missing i.e i2c/smbus.h and library i2c

[@hakonhksnes8929]

did you fix this? have the same problem

[@shantanuparab2280]

@@hakonhksnes8929 yes I fixed the issue. You can remove the i2c library dependency from the CMakelist file of the package. And remove the extern include smbus.h from the i2cpwmboard.cpp file

[@hakonhksnes8929]

@@shantanuparab2280 Thank you, wil try (Y)

[@hakonhksnes8929]

@@shantanuparab2280 What do you mean by "remove the i2c library dependency from the CMakelist file of the package". I removed the extern include

[@shantanuparab2280]

@@hakonhksnes8929 target_link_libraries(i2cpwm_board ${catkin_LIBRARIES}) find this line in your CMakeList file and remove i2c

[@tripleb5197]

Excellent tutorial series. I'm using this to program a SunFounder PiCar-V with ROS. It uses a PCA9685 servo board to control the steering servo and a movable camera, and I was able control the camera and steering directly, but for the two DC motors, it connects to a TB6612 motor driver. Going to look for a DC motor driver to control them next. Thanks a lot!

[@percho97]

Hi i'm following your tutorial but i'm facing a problem. The file smbus.h doesnt exist. I try to reinstall i2c-tools, libi2c-dev etc.. but noting create this file.. i dont know how to solve it.. if you have an idea..

[@XxPwnZsxX]

same problem :/

[@prasannamg2449]

Hi, I receive a no smbus.h error during catkin make. I have installed the libi2c-dev package,however i am unable to locate the i2c folder in the root directories. I searched for available solutions but the servocontrol package as mentioned had all the requisites....... Could you let me know which version of Ubiquity iso you had used here? Ill try with that OS version........or maybe an alternative help would do.I could locate smbus files but all were python related...No smbus.h

[@jcmay]

i have the same problem

[@MikeNewham]

Hey folks, My RC Car (a Tamiya TT-01 Type E) chassis is going 'toooo fast' when I control it with the keyboard :) I wonder if a parameter needs to be adjusted in 'class ServoConvert ():' within 'low_level_control.py' (as seen at 10:56) Should 'range=90' be increased? Or maybe the PWM frequency should be lowered (where would that setting be?). - When running the 'telex-twist-keyboard-node' - the Tamiya accelerates quickly from 'stationary' after pressing 'forward - I'. I then have to hit 'z' key instantly to 'decrease' speed multiple times. - Also, reverse does not work from 'stationary' after pressing 'reverse - '). I have to increase 'reverse' speed by hitting the Z key multiple times to get the Tamiya moving backwards. - I found a centre-value of 298 to be best for 'stationary' between both servos fro steering and throttle.

[@prandtlmayer]

The center value needs to be calibrated. You might want to write a script for that or a parameters file. In the file you could also set the values for saturating your commands. I wouldn't limited the servo range, but the commanded speed. For the reverse, that is true and it depends from the motor controller. You need to go back for the break, theen idle , then back again for backing up. Try also to incorporate the joystick rather than the keyboard

[@johanthps9647]

can we get the schematic diagram on which pins should we connect the servo control board to?

[@prandtlmayer]

I am pretty sure I show them in the video. You can always refer to the official RPi pinout page: www.raspberrypi.org/documentation/usage/gpio/

[@CJsk8inHD]

Great video man, direct and informative. I will definitely be stepping through this tutorial.

[@prandtlmayer]

This goes fast. Check out the others too!

[@LucasSchulzeRobotics]

A tutorial about ROS Control would be very interesting.

[@ozcankosar6206]

Does the ros-i2cpwmboard package support ROS Melodic? Will it work if I just install donkey_car and ros-i2cpwmboard on a Jetson TX2 with ROS Melodice?

[@prandtlmayer]

I don't know. If you don't find it when you try to install you can either build it from source or you can ditch the i2c servo adapter and use an Arduino

[@yufanwang8818]

cannot find i2cpwnboard package on gitlab

[@prandtlmayer]

Check my video where I bypass the i2c adapter and I use an Arduino

[@narpat007]

It was really awesome !, if possible pls use gaming joystick to control the car and in your further testing pls include object recognition and collision avoidance using OpenCV.

[@prandtlmayer]

That's the plan

[@ozcankosar6206]

Hello . I want to control it with my own python code. do you have source code?

[@cooldude6651]

Hi, I'm a new ROS developer and I love these tutorials. I was just getting started with ROS2, and I was wondering if there was any form of ROS2 tutorial series coming down the road. Most documentation I've found was either vague or vague but in C++, but you're very good at explaining the code.

[@prandtlmayer]

Not planning for that right now, but maybe in the future.

[@Flix-f6q]

please send a link here to the vague documentation in C++. Thanks.

[@AsimNaskar]

Very detail. But still could not understand how the Pi board is receiving Transmitter signal? Have I missed that part?

[@prandtlmayer]

The only commands that are coming to the pi are from wifi. The receiver has been disconnected. I actually have a video now that shows how to integrate the receiver with an Arduino

[@jonathansteele7349]

Great Tutorial Tiziano. Did you ever have the error that the servo works and changes the stering angle but the throtle motor does not ? Do you have any troble shooting sugestions ? I used the rostopic pub /cmd_vel geometry__msgs/Twist "linear: X 1.0 and then echo the servos_absolute msgs show servos 1 value is 378. Thank you for your time Tiziano or if anyone else had this problem I would appreciate the help.

[@prandtlmayer]

That is weird, tell me more about it. I would first try to see whether just applying a pwm (that you can generate either through the servo board or using some external source)

[@ozcankosar5416]

ssh: Could not resolve hostname ubiquityrobot.local: Name or service not known. I'm getting this error I couldn't find the solution

[@prandtlmayer]

Use the device's IP address instead then. Also, make sure you are on the same network and your IP address matches

[@ShmeegleSon]

Awesome, thank you for this series!

[@co4erol]

4:28 small typos fix. He write [catckin_ws_src] instead of [catkin_ws_src]

[@patrickpuentelml4958]

Hi Tiziano. I have a question because at the moment ROS had new distros called Noetic & Melodic. So, in this nice tutorial you are using ROS KINETIC an old distro. As a fully beginner (dummy) of ROS which of the new distros is the equivalen of KINETIC? and What's the difference between Noetic & Melodic distros?. At the moment I'm learning all the basic thing of ROS with Noetic and I need clear my mind when robot devoloper use Noetic, Melodic or Kinetic. HELP PLEASE!

[@prandtlmayer]

No problem. For many uses there is not much difference and it depends on your operating system. As I had to use Ubuntu 16, the only choice was Kinetic. But if you use a more modern release then you use the ROS distro that installs on your OS. You should be able to learn and port your packages among distros

[@fransflorenza9708]

can someone help me pls? i have an error while install servo package. the line said: FATAL error i2c/smbus.h: no such file or directory. note: im already install the i2c library and success...

[@sangeethcp2119]

Sir can u help me to get noetic operating system code for above robotic project ..

[@dhvanitdesai1044]

will you do a series for mavros like you did for dronekit ??

[@mfatihozkan3503]

Hello Mr. Tiziano. I am trying to use rpi camera with ros melodic. How can i use kinetic packages with melodic. Can you help me ?

[@prandtlmayer]

In theory you should be able to, as long as you have one roscore. What kind of problem you have?

[@priyanshugupta8552]

can i use ros noetic instead?

[@ruveydadilara]

How did you install ros2 on raspberry pi 5?

[@kartiksinghal810]

I am getting an issue with the i2c when using PCA9685 driver. the Arduino IDE is able to detect the i2c connection but it is not accessible from i2cdetect in the terminal. [ROS Melodic on Ubuntu 18.04 in VM] Any leads?

[@prandtlmayer]

I have not tested on melodic but I don't think that is the issue. Not a clue, sorry

[@trylatdar4012]

can you explain how to acces robot folders using samba plz ? beacause I can't acces it directly on my laptop like youy did. I'm on ubuntu 18.04 for the laptop and the robot is on the latest image onthe the website you link to us. Thanks

[@prandtlmayer]

You need to install and setup samba on raspberry pi. It should already be included in Linux

[@marcochunab4082]

hi, Tiziano i got a question. I try to run the i2cpwm_board but i got an error, it says that ros couldnt find executable named i2cpwm_board

[@prandtlmayer]

Chmod that

[@marcochunab4082]

@@prandtlmayer hi thanks Tiziano, i solved that already but Noe the cmake got am error because of the library of i2c

[@benaliamima9903]

Really appreciate your videos. Thank you Mr. Tiziano I can't drive my Picar-s using your code. i have one servo motor that control the front wheels (1) and two DC motors for rear wheels (servo =5 for the left wheel and 6 for the right). when i run your low_level_control.py code only i can control the front wheel by servo 1. but the two rear wheel did not move. I have 3 servo in my case and when i modify your id steering from 2 to 5 the left wheel move normally but the right one doesn't. What should i do to control the car as you. i hope that you reply me.

[@prandtlmayer]

That has nothing to do with ROS: It simply is a matter of mapping the controls to your own actuators. Create a simple script for yourself where you test the servos to understand how to map them

[@garapatianushadevi3427]

Just loved them! :) Can you please help me with this: If my motor control board has PWM interface, (not I2C), what are the changes to be made in low-level RC car code?

[@prandtlmayer]

Create a node that interfaces with your specific motor. This is you first step. Then the donkey low level control publish a topic that your new node subscribes to

[@atrocious00]

May I ask what the reasoning for the steering being set to z axis?

[@prandtlmayer]

standard robotics frame: x: right, y: forward, z: up

[@NexxuSix]

Tiziano, First and foremost, thank you for this wonderful tutorial! About three years ago, I tried working with ROS, using just the Wiki Tutorial, but didn’t fully understand how ROS worked, let alone, how to drive a single servo. Although your tutorial was a bit fast, and took me several tries sometimes to get things right, tonight I am proud to say I have a Raspberry Pi 4 with a Servo Hat operating two servos via SSH from my tablet! This is a really big step for me! So, next I plan to put the assembly on a car as you suggest, and keep working with the tutorials. One question though: In the tutorial you install ROS on both Ubuntu laptop, and Raspberry Pi, but in the end of the tutorial I understand that the Donkey Car can be controlled through SSH alone, from any tablet. What does the ROS installation on the laptop do for the Donkey Car? Thank you for answering my question!

[@prandtlmayer]

Thank you for your words. Great question: the reason why I went to the trouble of using the laptop too is because I want to show how to make Ros work in a network. This is a tutorial and the idea is that, in general, you have multiple computers and robots connected together

[@johnstreety6682]

I have followed your tutorial all the way up to the part where you get the wheels to move. When I run it, I get no errors but the wheels don't move. I thought it might be the batteries or some other hardware issue. So I reinstalled the Donky car software and ran the calibration for 3 hours last night(mainly to make sure the battery was good). I guess I was thinking something might have changed since you made this video. However, I did use the most recent version of of ubiquity which was 2020-11-07-ubiquity-xenial-lxde. Can you think of anything that might cause this odd scenario?

[@prandtlmayer]

Let's break the problem into pieces. First: do the motor spin when you use the normal radio receiver?

[@johnstreety6682]

@@prandtlmayer I got the wheels to move using the donkey car software. I am thinking it may have something to do with a Chinese version of the pca9685. I ran into that with Arduino and some other chips

[@marcosmit97]

rosrun i2cpwm_board ? Where do I get this file

[@hfe1833]

Thanks for the video tutorial, whats the advantages of using ROS because i dont use it before i have similar project but not using ROS??

[@prandtlmayer]

ROS Is a standard in today's robotics. If you want you can use your own libraries, you just need to write everything from scratch, communication, navigation, control...

[@TharinduIshan-tj2wr]

Great video series. Thank you so much Tiziano

[@alfiolocatelli5093]

Ciao Tiziano, scusami la domanda, ma non riesco a capire come mai tutto il procedimento si svolge tra PC e Raspberry. Non posso sviluppare i miei rosnode e quant'altro tutto interamente da Raspberry? Non capisco perché dobbiamo prendere in considerazione anche il PC.... Sono nuovo in questo campo, ho flashato ieri ubiquity su Raspberry e appunto mi chiedevo se dovessi fare una partizione ubuntu sul mio PC personale per "configurare" Raspberry..... Spero di essere stato chiaro nella domanda. Grazie in anticipo.

[@prandtlmayer]

Puoi fare tutto da Pi, semplicemente è più comodo usare un PC per connettersi in SSH

[@SrijitoGhosh]

Hello sir. I know, it's a bit late. I mean, its 4 years since the upload of this video but may you please answer my question, if I can use WSL for installing ros packages?

[@sonnchenundhomie]

How exactly do you connect the robot to your computer? I can't connect with ethernet connection, but with the access point. If i connect the RasPi to my computer with the access point, i don't have any internet connection to download packages.

[@prandtlmayer]

Connect the pi to your router using an Ethernet cable

[@sonnchenundhomie]

@@prandtlmayer Thanks for your answer! I'm gonna try that

[@sonnchenundhomie]

@@prandtlmayer Hi, your answer helped me a lot! But now the keyboard controlling doesn't work... I'm not using an Adafruit control board, but a L298n Motor Driver. The rostopic lists the cmd_vel topic and also the teleop node is outputting messages, but still the wheels aren't turning. Is it because i have different hardware?

[@florianneugebauer3042]

while running teleop_twist_keyboard I get the output: Waiting for subscriber to connect to /cmd_vel. I checked this topic with rostopic info /cmd_vel, and yes there os a Publisher (/teleop_twist_keyboard) and a Subscriber (dk_llc). I checked this on both sides(robot and local laptop) both are the same. So why does /teleop_twist_keyboard thinks there is no subscriber??

[@prandtlmayer]

That is a mystery actually, have you figured it out?

[@rouinisami3427]

i will use control L298N Driver with ROS but i don't find the node of L298N driver on github

[@abdelrahmanemam5559]

in minute 8 when i try to rosrun the control borad it give me fatal error cant set pwm and some other errors and cant open i2c bus

[@prandtlmayer]

Then you will love the latest video kzbin.info/www/bejne/jX25l42OrdV7j6s

[@Jiceism]

Hi Tiziano, thanks for these videos! Quick question before I wipe my computer. I am using Ubuntu 18.04, and ROS isn't supported on this version :( Anychance I can use 18.04 with another ROS distribution?

[@prandtlmayer]

Sure, you can use latest versions of Ros. My examples are pretty basics and you should be able to transfer the coding and knowledge to any other distribution, like Melodic. Try and post here your results. Or better on my Facebook page @tizianotutorials

[@prandtlmayer]

Check this out: answers.ros.org/question/76279/different-ros-versions-on-multiple-machines/

[@Jiceism]

@@prandtlmayer Thanks for your reactivity! I will check out as soon as I have some time and post results here and in Facebook page too!

[@prandtlmayer]

That's a very interesting question

[@Jiceism]

Hi @@prandtlmayer , so I took time to go over minor HW issues, and I can confirm using Melodic on my desktop works without any issue with the Donkeycar!

[@denq1016]

How did you install ROS in raspberry ? Do use ubuntu or raspbian in raspberry ?

[@prandtlmayer]

I did not, I used a pre baked image

[@arsalanwasim4177]

Sir, what steps should i follow for dc geared motor?

[@prandtlmayer]

What do you have in mind?

[@arsalanwasim4177]

@@prandtlmayer Salam respectable sir, instead of using servo motors, i want to implement this using dc motors using l298 motor driver to control motors,I have understood the procedure but what should i do to change the libraries of servo to dc ?

[@prandtlmayer]

You just need to replace the driver for controlling your DC motors. Write a library that controls the DC motors, that gets reference input. Then you ROSsify it following my next tutorials

[@arsalanwasim4177]

@@prandtlmayer thank you so much ,i'm new to the rasberry , that's i didn't understand, you truly rock one request though please post a video with gmapping as well

[@erhanwarsi2185]

Brilliant sir wonderful but in my 3 dof robotic arm there are two servo,s i am not aware from python script please sir can you help me?

[@enricosaccheggiani3192]

Hello Tiziano , I have created a robot car from 0 but the raspberry PI uses Raspbian. Do you think that is possible to run ROS on a Raspbian platform ? Thanks

[@prandtlmayer]

Use Ubuntu and save yourself frustration in installing Ros

[@fatmazehrasacakldr5921]

Can you help me? I get an error in "sudo apt-get install ros-melodic-desktop-full" step. I am getting the 'Unable to correct problems, you have held broken packages' error message.

[@prandtlmayer]

You need to refer to the documentation. Verify that your Linux version is compatible

[@fatmazehrasacakldr5921]

@@prandtlmayer I am using Debian 9. I installed Melodic. I solved the problem: answers.ros.org/question/282399/sudo-apt-get-install-ros-indigo-desktop-full-e-unable-to-correct-problems-you-have-held-broken-packages/ Thank you. Nice tutorial :)

[@duckietown2447]

Appreciate this tuorial. So we installed melodic and when we source /opt/ros/melodic/setup.bash . An error occured:: /opt/ros/melodic/setup.bash:.:8: no such file or directory: /home/badz41/setup.sh We would appreciate your help

[@squirrelbrains2197]

What directory where you in when you typed that? If you still have this issue, you may want to try to type "cd" first to go to your home directory and than try again.

[@narendrashiva9360]

Will it work on different networks? Means can we control it wherever we r in the world?

[@prandtlmayer]

Yes, you just need to make sure it is reachable from you. Check on the Ros forum

[@benaliamima9903]

Hi Tiziano, thanks for the awesome tutorial I want to know if i can implement this with my PiCar of sunfounder ?

[@prandtlmayer]

I believe so, just some modifications to the actuators and you should be fine

[@benaliamima9903]

@@prandtlmayer thank you

[@MrArdo-branch-main]

this is great but i cant find the right pin on the motors. can someone help me where to find the pin?

[@prandtlmayer]

What pin do you refer to?

[@MrArdo-branch-main]

@@prandtlmayer haha it's ok.. I get the pin😅😅 that motor driver.. thank you for replying my questions 🙏🙏

[@wesleybatista4024]

when I compile "catkin_make" the following error appears: "error:‘ i2c_smbus_read_byte_data ’was not declared in this scope oldmode = i2c_smbus_read_byte_data (_controller_io_handle, __MODE1); " can anybody help me ?

[@fulvian]

Ciao Tiziano, come ti dicevo sto seguendo il tuo tutorial per modificare una vecchia car rc. Hi seguito passo passo le tue istruzioni (direi correttamente) fino al Min 7.30 quando pubblicando il servoarray non ottengo alcun movimento del servo e nessun errore apparente. Dove potrei avere sbagliato? Ho verificato il collegamento gpio (ho seguito il tuo schema sda-3, vcc-4, scl-5, gnd-6) e alimentato autonomamente la i2c board con un esc 5v 2A. La mia configurazione è: Raspberry Pi 3 modello B + i2cpwm board pca9685 (adafruit clone) + ubuntu xenial ubiquity robotics OS image. Avresti qualche consiglio da darmi? :) Grazie Fulvio

[@prandtlmayer]

Innanzi tutto verifica che il cablaggio sia corretto ancora una volta. Se alimenti la scheda esternamente, non ti serve collegare il vcc della Raspi (anzi, non dovresti proprio). Verifica che la scheda funzioni eseguendo un semplice esempio github.com/adafruit/Adafruit_Python_PCA9685/tree/master/examples. Verifica che i servo siano connessi correttamente e di non controllare le uscite sbagliate. Verifica che i servo funzionino. La scheda clone dovrebbe funzionare allo stesso modo. Considera pero' che potresti farbe completamente a meno e usare Servoblaster per controllare i servo direttamente da Raspi

[@fulvian]

@@prandtlmayer grazie per i consigli. sto provando un po tutto, ma nulla si muove...

[@prandtlmayer]

Hai verificato che i servo funzionino, vero? Prova a collegare altri servo. La scheda di controllo servo funziona? Altrimenti collega il segnale servo alla Raspberry, installi servoblaster e riprogrammi la libreria di controllo dei servo per usare servoblaster. Puoi usare il mio video sul laser scanner come guida

[@fulvian]

@@prandtlmayer i servo funzionano (ahimè)!ne ho provati diversi... Ma niente. Sulla scheda i2cpwm comincio ad avere grossi dubbi anche se con i2cdetect la matrice mi segnala (se non ho capito male) correttamente (?) 40-40 e 70-70 è tutto il resto spento. Ora proverò ad usare servoblast, così da capire se il problema è la scheda i2cpwm. Ti aggiorno...ancora grazie mille

[@pradiptabiswas2393]

Loved your first tutorial. I have a Redbot and an Adafruit I2C motor control board lying around at home. Can I use that for this whole tutorial? It uses two DC motor. Will it be complicated to uses DC motor instead of a servo motor to follow your tutorial? Thank you.

[@enlyse]

Cool content Tiziano! Keep it up! :)

[@KanagachidambaresanGR]

[rosrun] Couldn't find executable named i below /home/nvidia/catkin_ws/src/ros-i2cpwmboard .,., hi i got this error,., can you help me.,

[@meheras7512]

How can we follow a fixed trajectory using a GPS system?

[@prandtlmayer]

Throttle: command forward. Steering angle: command with a PID respect to the deviation from the straight line

[@ajelvani]

#0? A true computer scientist

[@omerfeyyazselcuk7325]

That wears like mad physicist.

[@hosseins5179]

Hello. Thanks for good tutorial. Can I install ROS on raspberry pi 2+?

[@prandtlmayer]

The question is whether you can install Ubuntu. Check where I source my SD card from to see if they have an image ready

[@xHnTRxCLan]

Hi Tiziano, thanks for the great tutorial ! I followed everything you did in the video, but at 14:40 I got this error " Command 'rostopic' not found," I checked the ubiquityrobotics's website and I found that they only supports Ubuntu 16.04, and I'm using Ubuntu 20.04. So is there any possible way I can make this work in the version I'm using ?

[@prandtlmayer]

did you source?

[@ОлексійСавченко-л7е]

Good tutorial! Thanks!

[@benaliamima9903]

Hi Tiziano, thank you for your videos on ROS. I want to know how to control DC motor not servo motor using the i2c pwm board package to drive the car forward and backward

[@prandtlmayer]

You need a DC motor driver, and most of them accept pwm input.

[@fransflorenza9708]

i found that ubuntu ver 16 doesnot have lib smbus.h even we installed it using command libi2c-dev. my question is. so how this tutorial can using that lib even using ubuntu 16.

[@prandtlmayer]

I am sorry about that, as a matter of fact that library has been very problematic for many people. I will look into that. You can also create a PWM control node on the raspberry using servoblaster and then connect the two servo control pin to the Pi

[@fransflorenza9708]

@@prandtlmayer very thanks for your reply. so im now uisng ROS melodic in my rasphi. is there anyway to controlling it via ssh like ubiquity robotic?

[@fransflorenza9708]

solved by enabling ssh control manually

[@ismaelleoncumplido5075]

Which ubuntu are you using for kinectic?

[@prandtlmayer]

Lubuntu 16.04

[@divyaprakashbiswas8781]

Sir, thank you for sharing this video. What editor are you using to edit the donkey_llc.py at 10:50, because you have ssh into raspberry pi?

[@prandtlmayer]

PyCharm

[@eruditeboen3860]

When I publish ServoArray and set the values it gives me "ERROR: Unable to communicate with master!". Why?

[@prandtlmayer]

Because you are not connected to master node. Either is not running or you have not set the ROS_MASTER_URI

[@eruditeboen3860]

@@prandtlmayer Oh it works now thank you :)

[@luqmansen]

Nice tutorial, great example for my project, huge thanks !

[@ChoupyPeluche]

Hey mate ! your tutorial is awesome but EVERY step got me tons of problems haha. I managed to overcome every problem but I'm totally facing a wall right now... I don't know why but when I do the "rosrun i2cpwm.... i2cpwm...." part, I get fatal messages saying it's not possible to connect to the i2c-1 thing. But when I check i2cdetect -y 1 on the system I get the good response with the connected pins. So I'm not sure why it wouldn't connect (I'm using rpi4). If you have any answer I'd be glad to read it because I have really no idea :( . The i2c works because I tested the system with raspbian and basic donkey tutorial got my motors running.

[@prandtlmayer]

I haven't tried on a Pi4 but I'm sure it's the same as my 3. Try and use one of their python test scripts

[@fransflorenza9708]

hi, i get the same problem too, have you solved this problem?

[@fransflorenza9708]

solved by execute as super user

[@embedded_system]

Sir I don't have extra monitor for raspberry pi, can I access by by using ssh and realvnc permanently? I can access pi only first boot. After shutdown on of system .I can't access pi ? What's the problem?

[@prandtlmayer]

Sure you can, follow my tutorial

[@embedded_system]

@@prandtlmayer thanks

[@quentinwiame9344]

Thanks bro for your help ! PS : We are french

[@kyozho3912]

hi, do you know how to connect YDLidar from raspberrypi to ubuntu 16.04? i want to use rviz with ubuntu 16.04 to see the laser lidar from YDLidar raspberry pi machine. do you know how to connect lidar from network connection as raspberry pi as a server?

[@prandtlmayer]

There is one video of the series talking about that

[@fatihozkan2141]

How can you see Raspberry Pi folders from your laptop. With ssh? Anyone knows?

[@fatihozkan2141]

Found it! In folders - > other locations - bottom of the window you will see empty bar with connect button. Write ssh://username@ipaddress/folder name. Change username ipadress and folder name with your identities

[@prandtlmayer]

Good catch. You can also use the Free(ware) software Mobaxterm for an integrated ssh and sftp environment

[@joshtradesict]

Hi ,I'm new to Autonomy and Computer vision robotics cause i only used arduino and raspberry pi.....What is the difference between these Ubuntu, ROS, openCV, MATLAB...do i need all this to make a robot??

[@prandtlmayer]

Those are just tools. You need passion and some background on math, coding and robotics. Ubuntu is an operating system, like windows. Matlab is a program specific for math and matrix computation. Ros is a suite of libraries for simplifying putting together robots and sensors

[@squirrelbrains2197]

Ubuntu is a Linux based operating system. It is best suited for running ROS, the Robot operating system. Robotics is a big field that offers a lot of things for you to learn. You do not have to become a specialist in everything that you just mentioned. Learning to code is very help full though.

[@azouaousmile]

Really nice video. Thank you so much for uploading it. I was wondering what version of Ubuntu are you using on your laptop?

[@prandtlmayer]

Lts 16.04

[@azouaousmile]

@@prandtlmayer thanks 👍👍👍

[@henryantonioquispepizarro2291]

Now, i'm using ROS Melodic. If i want to development this project, Is it necesary to change MELODIC to KINETIC?

[@prandtlmayer]

Packages are ROS distribution dependent. ROS distro also depends on the Linux version. Check the wiki page of the packages you want to verify whether they are available or not.

[@동그리동동-l5k]

Hi Tiziano. First of all, thank you for uploading video about using ROS. But I have an one problem. That is I cannot connect to the donkey car using ssh. I can show the error message "ssh: connect to host XXX.XXX.XXX.X port 22: Connection refused" What's the problem? I googled again and again but could not find the answer. Write a comment on the straw.

[@prandtlmayer]

Are you connected through its wifi?

[@우짱-g8y]

@@prandtlmayer Yes. my pi connected my wifi

[@HaniSharif]

Thank you.. really appreciate this❤️ keep teaching

[@anukeshambatkar6255]

sir how can we make a user follower robot using raspberry pi and camera for shopping purpose

[@haziqahmad6802]

Thanks, I like your video. Can you create a video tutorial about how to connect ROS + Raspberry Pi 3 + LiDAR + motor control. I like to build an autonomous RC car using LiDAR.

[@prandtlmayer]

Now that is on the line. We are going to have some fun with sonar pretty soon also

[@GurusCooking]

awesome, even i was thinking of asking @Tiziano Fiorenzani to do this video, would be of much help he's a great teacher

[@tuantrananh2967]

I am having trouble sharing folders from ubiquityrobot (rasp pi) with ubuntu 16.04. I tried many ways but was not successful. Please help me. thank you!

[@prandtlmayer]

I had no problem with that. Did you set the password with smbpsswd?

[@CodingScientist]

This is FANTASTIC Tutorial, it would be helpful if you could show the circuit / pin level diagram to build the Robot, each pins connecting which components etc

[@prandtlmayer]

Noted

[@benjamingp7442]

Great video! I have this all working on a 4x4 motor bot and using rostopic pub -1 /servos_absolute i2cpwm_board/ServoArray "{servos:[{servo: 1, value: 1000}]}" works. My motors are 1,3,5 and 7. What I can't work out is how to make them run in reverse!

[@prandtlmayer]

Nice work! Reverse depends on the motor controller. Usually a reverse command makes the controller to enter a brake, while reversing twice enters the actual reverse

[@boardsdiscovery5803]

Speed Light is great for me :) I don't like wasting time in not so important details. Nel video all'inizio non capivo l'assenza del driver per i motori cc. Poi ho scoperto che il motore per la trazione è un brushless! ora tutto è chiaro. Bello stile. Complimenti.

[@prandtlmayer]

Nel prossimo aggiungeremo i sonar

[@boardsdiscovery5803]

intendevo dire che le lezioni veloci mi piacciono :)

[@prandtlmayer]

Avevo capito. Sono stato troppo succinto nella risposta. Volevo dire, che il prossimo video sarà veloce perché aggiungeremo i sonar e spiegherò il tutto molto velocemente. Anche a me piacciono video veloci

[@gzizouhassine5777]

Can you make video on autonomous drone based on open cv, dronekit, neural network, ros plz

[@prandtlmayer]

step by step we'll get there

[@prasobhprakasan5921]

what IDE used for programming?

[@prandtlmayer]

The one you like the best. I used none here, or sometimes I used Notepad++

[@sowande1234]

I tried connecting the pi via ethernet and ssh [e-mail], but i keep getting error message 'ssh: Could not resolve hostname ubiquityrobot.local: Name or service not known'

[@prandtlmayer]

Make sure your computer and the Pi have the same IP address family, like 192.168.1.xxx

[@prandtlmayer]

Also, try and drop the .local

[@sowande1234]

It started working when I disconnected the Ethernet and instead connected to the network generated by the Ubiquity image

[@thebeatgeek1]

Thank you for creating this tutorial it was super helpful. I was able to follow you video, but I at the point where you create the low_level_control.py file and I do not know how you created that file and where you put it. I thought I put it in the catkin_ws/src/donkey_llc location but ros says that the file is not executable.

[@squirrelbrains2197]

Did you tell your Raspi that this file can be executed? To do so, navigate to the folder of your file than type "chmod +x low_level_control.py " into the terminal (without parenthesis).

[@ConsultingjoeOnline]

Great video thanks!!!