To go back to the Overview page click here.
To go to The Next Session - Robotics1b - Building an mBot Programme
To download this as a .pdf:

Download as PDF

What we’re going to do in the session.

mBot and Interface Banner

The mBots

mBots are fully programmable using Scratch (with some additional blocks) and the Arduino microcontroller coding language. They neatly bridge the gap between Scratch, Robotics and the huge world of the Arduino microcontroller.

Venn Diagram of Arduino, Scratch, and Robotics

As standard they have a number of sensors:

Overview of mBot on-board sensors

The mBots can be programmed through a wireless connection as well as using a USB cable to upload your programmes.

The mBlock Interface

The mBlock interface for programming the mBot is built on Scratch2 which you will probably have already encountered. The only differences are;

mBlock Scratch 2 Interface for mBots
mBlock Scratch 2 Interface for mBots. Click on the image for a Hi-Res view.

You can run your Scratch graphics programs and games with this interface as well as program the mBot. If we open the Arduino View (Access that through the Edit Menu dropdown), it looks like the following view. The “Upload to Arduino” button is the magic one to send our programs through to the mBot.

mBlock Arduino View
The mBlock Arduino interface. Click on the image for a Hi-Res view.

mBot Capabilities

The default programme in the mBot has three modes that we can access using the black button on the top left hand side (looking from the back). Each press of the black button changes the mode to the next one.

The three modes are;

mBot magic button to start the show

Mode 1 – Infrared Remote Control

When you first turn the mBot on the robot will sit there blinking coloured lights and not doing much else. If you have the Infrared Remote, you can drive the mBot a bit like you would a remote control car. You will need to point the remote directly at the mBot to make it go. The next diagram shows the controls.

mBot IR remote

Mode 2 – Obstacle Avoidance

In this mode the mBot is acting like a true robot. It guides itself around the room using its Ultrasonic Rangefinder (the eyes) to watch out for things it could bump into. It uses the sound echo off objects to “see” a bit like a bat does.

Mode 3 – Line Follower

In this mode the mBot will follow a line you draw. The sensors on the underside of the front detect the edge of a thick line. It works by checking the difference in reflected light between the two parallel sensors. It only works with quite wide lines so if you are going to mark your own lines for it to follow, they will need to be 20 -25mm wide. Using strips of black paper is an easy way to make lines and curves for it to follow.


That’s it for this first session. We now know what basic things the mBot can do.

Next Time: Building a program for the mBots. We will look at how you construct and upload a basic program to the mBots.


Creative Commons by-sa

This document “Robotics1a - Introduction to the mBot” by Hamish Trolove is provided under a creative commons license - Attribution, Share Alike.