Tutorial: Building BALANC3R

BALANC3R_small

This tutorial provides step-by-step instructions to build BALANC3R, a self-balancing LEGO MINDSTORMS EV3 robot.

Requirements

LEGO MINDSTORMS EV3 Home Edition
1x LEGO MINDSTORMS EV3 Home Edition
  • 1x Gyroscopic Sensor. Use one of the following sensors:
  • Both sensors work great in this project, but here are some considerations before you buy:
    • The EV3 Gyro is cheaper. It can measure the angular rate and estimate the accumulated angle. The accumulated angle is not used in this project, but it may be helpful for other projects, such as making accurate turns.
    • The HiTechnic Gyro is more accurate for this application because of the increased resolution. It can only measure angular rate.
LEGO MINDSTORMS EV3 Gyroscope
1x LEGO MINDSTORMS EV3 Gyroscope

Building Steps

Build the robot by following the steps in order. Click on the pictures for a bigger image. Be sure to connect the motors and sensors to appropriate port on the EV3 brick as indicated by the port icons.

BALANC3R_01

BALANC3R_02

BALANC3R_03

BALANC3R_04

BALANC3R_05

BALANC3R_06

BALANC3R_07

BALANC3R_08

BALANC3R_09

BALANC3R_10

BALANC3R_11

BALANC3R_12

BALANC3R_13

BALANC3R_14

BALANC3R_15

BALANC3R_16

BALANC3R_17

The following two steps are for the LEGO MINDSTORMS EV3 Gyroscopic sensor only. Skip these steps if you have another sensor.

BALANC3R_18

Attach the LEGO MINDSTORMS EV3 Gyro sensor as follows. Be sure to connect it to the side of the EV3 brick with the USB port.

BALANC3R_19b

The following two steps are for the HiTechnic Gyroscopic sensor only. Skip these steps if you have another sensor.

BALANC3R_20Attach the HiTechnic Gyro sensor as follows. Be sure to connect it to the side of the EV3 brick with the speaker.

BALANC3R_21b

Programming

Now that you’ve finished building your robot, you’re ready to program it. See this article for instructions.

drivecontrol1
Click to go to the programming tutorial.
46 Responses
  1. Tomas Naslund

    Nice!Really looking forward to the program. I’ve been trying to wrap my head around the “segway”-programming for some time. Always ending up with my robot falling flat with both wheels full throttle in random directions:) Please tell me there will be an step by step tutorial for the programming as well! I’m dying to get it all explained to me! You are doning a great job! Thanx /Tomas

  2. Ronald Ledford

    Just finished building your Formula EV3 Race Car. Enjoyable project. I plan on having a programming joy using RobotC. But yet, the remote control program is keeping me busy driving the car.

    In the meantime, I having been looking at your BalancE3 robot. I will have to use my NXT motors instead of the EV3 motors. It will be interesting to see if your program will work with no problem.

    1. Hi Ronald,

      Great to hear that robot was fun to build. Maybe after you’ve tried the BALANC3R project, you can make the Formula EV3 Race car balance on its two rear wheels, and continue controlling it with the remote 😀 (It’s one of the challenges at the end of the balancing tutorial)

      The NXT motors are indeed quite comparable. Actually, I find them to be slightly more precise because they seem to have less backlash, which is good for balancing.

      When rotating in place, you’ll notice that BALANC3R balances almost perfectly, while it moves back and forth while trying to stand still. That’s because when standing still, it constantly moves back and forth across the backlash. While turning, it’s always on one side of the backlash.

      Laurens

  3. Ben

    Hello Laurens,
    I’m sorry that I posted this comment here but it wouldn’t work on the other page. I bought your book on my kindle but I saw the BRICK SORT3R so I put in the password in figure 15-9 and it didn’t do anything when I submitted it just looked liked it refreshed the page. Am I doing any thing wrong?

    sorry for posting on this page it was one of the pages that didn’t have passwords on it,

    B-D

    1. Javier

      I think $180 is a bit too steep for a recolored NXT. It would be cool if LEGO could make falceeatps in different colors that you could swap out (A clear one to display the internals would be awesome!)

  4. Arafat Qureshi

    Hello Laurens,

    Great site and book. I will order that. I am taking and advanced Robotics course this fall and we will be using EV3. But a lot of advanced programming will be in leJOS. Do you have a book recommendation for leJOS programming?

    Thank you and keep up the great work.
    Best wishes

  5. Irvin Stafford

    Laurens,

    I have used and enjoyed your EV3 book very much.
    The Balanc3r ‘bot is fantastic!

    I added an Arduino UNO, Emic2 text to speech module, EasyVR voice recognition module, Bluetooth module, Pixy CMUcam5 video camera, and a FrSky RC receiver to my Balanc3r ‘bot that I call Wilber.
    He is to have 5 modes of control and speech:
    1) IR control using the EV3 Beacon
    2) Voice recognition control
    3) Bluetooth-cell phone App. 1
    4) Bluetooth
    5) RC control
    6) Video control

    The basic idea is to convert all the control sources to ‘speed’ and ‘steering’ values.
    I was able to get each control mode working on a breadboard but have not combined them. The IR control and RC control are working now.
    I used Dexter Industries I2C block to communicate between the EV3 and the Arduino.
    Here is a short movie of Wilber under IR control.
    https://www.youtube.com/watch?v=DiGyeV759JE

    Again, thanks for creating such a great platform!

    Irv Stafford

    1. Hi Irv,

      Thanks a lot for your comment. Sorry I didn’t see it before—I have to manually review any comment with a URL in it to reduce spam.

      Glad to hear you liked the book. The extended Segway project with sound is impressive, nice work!

      Best,

      Laurens

  6. Peter

    Hey Laurens,
    I have buildet jour balancer and i have building a line follower from that, i can give jou the instructions and the ev3 programm, THATS REALY WORK!

  7. Peter

    Hey laurens peter here!
    I need a challange to build an robot, why an DUCKS3GWAY or a realy fast car
    Or… Can jou reply and write it?ok. HAPPY HALLOWEEN!!!!

  8. Aubrey Johnson

    Laurens,
    Enjoying your excellent book received as Xmas gift.
    Have you published any new build instructions as I’ve completed just about everything out there, but just not creative on my own at 78, ha.

    1. Hi Aubrey,

      Thanks for your feedback!

      You can also build all 12 bonus projects in the LEGO software under the “more robots” tab. I designed the RAC3 Truck.

      And then there are the 150+ challenges in my book 🙂

      Best,

      Laurens

  9. bluhhhhh

    hcdbc xhzcchadwet qyfehw4brsdncxfgwq7asufhbcewuysr you are duhhhhhhhhhhh and bluuuuhhhhhhhhhh code for…………..

  10. Daniel Piquée

    really congratulations for this wonderful project
    I would like to operate under Lejos
    Is there a java version of this program?
    Thank you for your response

  11. Alfredo

    Hi Laurens! thanks for sharing your designs! We have a EV3 #31313 Home Edition and just got the Educational Core and Expansion sets! Do you have any ideas on how to combine the three of them to build a BIG robot?? Thanks!!

  12. Pereira Aderito

    I have a EV3 kit and I have already built my two wheeled robot.. now i have been asked to program the robot using c language !

    1. Cadan

      I had same issue at fist. My son would start it and the robot would spin out and get ERROR. I found I needed to do a lot of trial and error finding the balance point before starting program. if it was slightly off balance, I would get the ERROR. Stick with it and really concentrate on keeping it balanced before pressing start. And hold the robot as lightly as possible. Sometimes having two people helps. One person lightly balances the robot using two hands, and when they find the balance point they tell the other person to press start. that often helped us. Also be sure the cables are all plugged into the proper ports. just a few things that worked for me.

      hope that helps.

  13. Cadan

    Ok, so far very cool program. I built the Balanc3r. I can get it to balance in place, however when I run Balanc3r Remote Control, it does not move. I have my remote selected to position 1, as in the program, and I click all the buttons but no response from the robot.
    Any ideas, tips, suggestions??

    1. Cadan

      Nevermind…the instructions showed plugging infrared sensor into port 4, but the program showed port 3 for the remote control. I switched the cable into port 3 and it worked perfectly! Thanks!!

      Also, as a tip, I found I needed to do a lot of trial and error finding the balance point before starting program. if it was slightly off balance, I would get the ERROR. Stick with it and really concentrate on keeping it balanced before pressing start. And hold the robot as lightly as possible… just a few things that worked for me.

  14. Cadan

    I had same issue at fist. My son would start it and the robot would spin out and get ERROR. I found I needed to do a lot of trial and error finding the balance point before starting program. if it was slightly off balance, I would get the ERROR. Stick with it and really concentrate on keeping it balanced before pressing start. And hold the robot as lightly as possible. Sometimes having two people helps. One person lightly balances the robot using two hands, and when they find the balance point they tell the other person to press start. that often helped us. Also be sure the cables are all plugged into the proper ports. just a few things that worked for me.

    hope that helps.

  15. Andrew

    Hey, guys. My BALANC3R is not working. I tried Cadan’s troubleshooting tips, but it still did not work. I reset the gyro sensor and even checked that everything was done correctly. My robot is still not balancing. Whenever it tries to move it falls down in the IR sensor and tries to move around like that.

    Please help me resolve this issue.

  16. Renos

    Hi Lauren,

    Great project. Thank you for all instructions. Everything is working fine as long the robot is “balancing” before program starts.
    I have a question: I replaced remote controlled part with one that follows the beacon. Tried a lot but always robot falls (Beacon following program alone works fine).
    Any ideas what might be wrong?
    Thank you for your time

  17. Elle R.

    Hello!

    Great code! I have been spending a bit of time reverse-engineering it!
    I am currently trying to code a version of the BALANC3R which is a spin-off from this one.
    The point of my code is to be more compact and simpler, only saving the essential components that cause it to balance.
    Near the end of the code, there is a “Wait” My Block, and without this My Block, your code functions exactly how my code does currently–it moves in the right direction with a good speed, but where “0” is changes from side to side until it goes out of control.
    The “Wait” block has a dt and a wait condition which resets timer 8. Would you mind please explaining what this My Block does, why you chose this particular dt, and where/what timer 8 is, along with any other relevant information?

    Thank you so much!

  18. Marco Malfatti

    Hello Laurens, thank u for your book. I am trying to do something with my new EV3 (is my daughter’s to say the truth). The problem is that after some project of your book (line follower etc…) i’am trying with balance gyroboy. This one is a very hard work for me, although i have now a lot of free time to spend (for the COVID19) i can’t understand the program so much. OK Laurens but what about a video tutorial for this program? (or a book :-). Thank u from Italy

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