Humbot mi:sumo assembly

What are we going to do?

We are finally going to start assembling the great Humbot mi:sumo robot!. It uses two DC motors and a motor driver and it's controlled by the micro:bit board.

We'll provide 3d printed parts at the workshop but you can always print them if you have a 3D printer at home. You'll find the stl files for printing it on this link and also on the list of materials.

In this activity you'll need two micro:bit boards, one for the robot itself and another one will be used as a remote controller. So in this particular activity you'll need to find a partner and work in pairs.

As all this process is going to take longer than our usual activities, we're going to work for more than one session. Follow these steps in this particular order:

  • First assemble the robot
  • Then connect all components
  • Finally, download and send the code to the boards (one on the robot and one as a remote controller)


micro:bit board

The micro:bit was designed to be classroom-friendly from day one. More approachable than just coding, it's a great way to achieve fun, practical results with motivated students. Buy from here starter kit (recommended) or board only.

motor driver

The micro:bit motor driver let's you control various components such as motors or servos

battery holder

4xAA battery holder to power the robot

4x Medium screws

4x M3x30mm screws, and screwdriver. They are mentioned as "medium size" on the video.

12x Small screws

12x M3x8mm screws, and screwdriver. They are mentioned as "small size" on the video.


You'll need 2x motor and wheel and solder a pair of cables (I use 22awg) to the motor. Soldering tool and tin lead

3D printed parts

3D printed parts can be downloaded from MyMiniFactory for free


micro USB cable

If your micro:bit board didn't came with a USB cable, any microUSB cable should do the trick


The code editor is web based, so any computer with a web browser (and Internet connectivity) will do


2 Connections

Use the following connections diagram or follow the video

Click here to watch the connection instructions video

Click here to zoom the diagram

3 Code

Here you have the code, if you want to see the code or modify it, you can import it from your editor.

Remember that you need one code for the remote controller and another one for the robot itself. Here you have both:

Download Robot code

Download Remote controller code

4 Upload to the m:b

Now, connect your micro:bit board to your computer using the micro USB. Your computer should now detect your micro:bit just as if it was an external drive. Search the HEX file you just downloaded and drag and drop them on your micro:bit drive. On windows you can right button on the HEX file and click send to MICROBIT. Remember that there are two different programs, one for the robot itself and another one for the remote controller.

Click to zoom

5 Controls

After a few seconds, your program should start on your micro:bit board.

To control your robot, press A to turn left, B to turn right, A+B to go straight and shake to stop.

Congratulations, you're on the right path to be a maker!, now continue with the following challenges! 🙂

6 Let's play!

Now it's time to have fun! Find a partner and start a sumo robot battle!

Now it's your turn!

Now that you have tried the robot, you may have noticed that it doesn't turn right and left equally. That could be caused by the motors. If you have this problem, don't worry, you can fix it by changing the values that make each motor move. If you don't have this kind of problem, it's also interesting that you follow this instructions because you can change the speed at which your robot is moving. Either way, here you have the instructions:

  • Open the robot code from your editor and take a look at the red blocks.
  • Where it says analog write, followed by a pin number and a bigger number. That last bigger number is the one that we should change to make it go faster or slower.
  • This number can be adjusted from 0 to 1023 (slower to faster).
  • Make some changes and find the best speed to make it manageable


What else?

Now that we control the Humbot mi:sumo, are you ready for a battle?

You can draw a circle (with tape) on the floor and you can make some battles between robots. Who will be the master Humbot?


Continue your maker journey with the next activity: Humbot mi:sumo BT control

or return to maker workshop main page