Makeblock mBot2 User manual

1 | P a g e
Digital Technology
MakeBlock mBot2 / CyberPi
Block Coding
Version 1.0 Barry Butler
Feb [e-mail]

2 | P a g e
Content and Challenges
Section
Content
A
The mBot2 Vehicle
B
Introduction and Setup
C
Our First Program –Hello
D
Push the Buttons
E
Run the Motors
F
Avoid or Seek
G
Detect and Follow a Line
H
SumoBot
I
Connect Servos, Sensors and Motors
Appendix 1
CyberPi Extras
Documentation
https://www.yuque.com/makeblock-help-center-en/mblock-5
CyberPi Blocks https://www.yuque.com/makeblock-help-center-en/cyberpi
(including Pocket Shield, mBot2 Shield and mBuild Modules)
Firmware Update
To update the CyberPi firmware:
1. Open the online ide at https://ide.mblock.cc/#/
2. Click on Devices and add the CyberPi device to the list, if it is not there already
3. Click Connect and connect the CyberPi (download and install the device driver, if asked)
4. Click on Settings and select Firmware Update

3 | P a g e
A. The mBot2 Vehicle
Documentation
MBot2 Introduction
https://education.makeblock.com/help/cyberpi-series/cyberpi-series-cyberpi-
series-packages-and-extensions/mbot2-introduction/
Operational Guide
https://education.makeblock.com/help/cyberpi-series/cyberpi-series-cyberpi-
series-packages-and-extensions/mbot2-operational-guide/
Python Reference
https://www.yuque.com/makeblock-help-center-en/mcode/cyberpi-api-
shields#9eo89
mBuild Modules (Ultrasonic Sensor 2, Quad RGB Sensor)
https://www.yuque.com/makeblock-help-center-en/mcode/cyberpi-api-mbuild
or
https://education.makeblock.com/help/mblock-python/mblock-python-editor-
python-api-documentation-for-devices/mblock-python-editor-python-api-
documentation-for-cyberpi/mblock-python-editor-apis-for-mbuild-modules/
The Build The Connections
(Ultrasonic into the mBuild port, motors to EM1/EM2)
The Power Switch must be turned on
before the you can upload code

4 | P a g e
B. Introduction and Setup
Download and Install the Software
Download and install the mBlock Windows or Mac software from https://mblock.makeblock.com/en-us/download/
(The PC software seems to be more stable than the web version located at https://python.mblock.cc/ )
1. Run the MakeBlock software
Mode switch File menu Rename project Coding space
Connection button
When you Connect and change to Upload mode the Upload button appears, to upload code to the mBot2.
Click the Setting button to carry out a firmware update and set up a wi-fi
connection.

5 | P a g e
2. INSTALL AND UPDATE BLOCK MODULES
If the mBot2, Ultrasonic Sensor 2 or Quad RGB Sensor pictures have a plus or update symbol on them, click
on this symbol to add or update these blocks.
Click the Add buttons to add these block sets to your software.
3. TURN ON THE MBOT2 USING THE SWITCH ON THE SIDE
The lights on both the ultrasonic sensor and the line follower sensor should turn on. If they are don’t, the
wiring is incorrect or unplugged, and needs to be fixed.
4. Select Upload mode.
5. Plug the mBot2 into a USB port and click the Connect button .
Select your USB port from the list and click Connect.
Find Your Port
You can easily find your device by first
leaving your mBot unplugged. Click
Connect and look at the list of USB ports.
Close the connect window, then plug in
your mBot2. Click Connect again and
look for the port that has just been
added.

6 | P a g e
6. Click on the File menu and select New Project.
7. Start coding

7 | P a g e
C. Our First Program – Hello
Our first program will write ‘hello’ on the console, say it on the audio speaker and turn all LED’s to green for 2
seconds.
Click the Upload button to send your code to the mBot2.
The code will start executing immediately it is uploaded.
Unsuccessful Upload
If the upload is unsuccessful check three things:
1. The mBot2 is turned on (the power switch on the left side).
2. The cable is plugged in and a connection established (see section B4).

8 | P a g e
Save the Project and Upload to the CyberPi
Save the project to your computer by clicking on the File menu and choosing Save to your
computer.
It is a good idea to create a folder to contain all your projects.
Make sure you type in a descriptive name for your file.

9 | P a g e
D. Buttons
The mBot2 is controlled by a module called cyberpi. This has a joystick, a home button and two push buttons (A and
B). We can use the joystick and buttons in our code. It also has a light sensor and microphone that we can use.
Instead of the code running automatically when it is uploaded, let’s turn on the display when we press button A.

10 | P a g e
E. Run the Motors
There are a number of ways we may want to move the mBot2. The blocks we need are in the mBot2 Chassis group.
Movement
Commands
Forward or backward
forever.
(Should only be used when the
ultrasonic sensor or colour
sensors are used to control
when the motors should stop)
Forward or backward for
a length of time
Forward or backward for
a fixed distance
Turn on the spot for a
length of time
(wheels turning in different
directions)
Turn for a number of
degrees of heading
Gradual turn for a length
of time
(wheels turning in the same
direction or one wheel
stopped)
Stop motors
cm
seconds
forever
time
degrees
time

11 | P a g e
Code Templates
There are two basic code templates we use when running motors. In both cases, we use button A to turn on the
mBot2 to start the actions.
Separating code into sections makes it much easier to understand the code and make changes to it. Later, we will
add more sections as we require them.
1. Single Actions. Use this when the mBot2 actions should only occur once.
If we have actions that are repeated, we can use a for loop. For example, to move in a square:
CHALLENGES
1. Place one or more large objects on the floor. Navigate the mBot2 through and/or around them.
2. One of the RoboRAVE competitions is AMAZE-ing. It consists of a series of boards that make up a maze. You do
not know the shape of the maze until the competition. The person who keeps the robot on the boards and has
the fastest time wins.

12 | P a g e
2. Forever Actions. This code has a while True loop that repeats the actions forever –or until you press the home
button next to the USB connection.
This code is mainly used in conjunction with the joystick and buttons, or the ultrasonic and line follower sensors,
where the mBot2 will respond to changes in sensor values.
CHALLENGES
3. Place two small objects on the floor at least 1m apart. Drive around these multiple times in a figure of 8. When
you turn use the led’s to indicate your turns.
4. Place a large object on the floor and turn around the object 3 times in a large, smooth circle.

13 | P a g e
F. Avoid or Seek
The Ultrasonic Sensor is used to measure the distance between the mBot2 and anything in front of it (up to about
200cm). It can be used to avoid obstacles or seek out an object and move toward it.
The minimum distance detected is about 4cm. Smaller distances give a reading of 300.
Test your Ultrasonic Sensor with this code. Putting all the sensor reading code into a function unclutters the main
loop.
Obstacle Avoidance

14 | P a g e
Slow Down when Close to a Collision
Seek Objects and Move Toward Them
Rotate to detect an object closer than 80cm, then move toward the object.

15 | P a g e
CHALLENGES
5. Place 4 objects at the corners of a square. Find one of them and stop before you hit it. Turn and find the next
object, until you have found all four.
6. Find your way autonomously through a simple maze (sides are 10cm high)

16 | P a g e
G. Detect and Follow a Line
The Quad RGB Sensor (color sensor) enables us to detect and follow lines, and detect colours and respond to the
colours in different ways.
Test the Sensor using either of these, by passing the mBot2 over a black line on a white background and checking the
displayed message and lights.
Error in both
code reading
quad sensor

17 | P a g e
We can use the color sensor values to test whether the color sensor is on or off a black line.
•On a line will give a low reflectance value or off a line will give a high value.
•Assume for a start that if the reflected light value is less than 50% if we are on or near a black line.
•Place the mBot2 on the middle of the black line
•If both sensors L1 and R1 are on black –go straight ahead
•If only sensor L1 is on black –turn to the left
•If only sensor R1 is on black –turn to the right
First, test the code below without the motors driving. Then take off the comment # and try with the motors running.
Error in code
reading quad
sensor

18 | P a g e
To follow the line faster, you might need the change:
•The power to the left and right wheels
•The difference in power between the left and right wheels
•How you interpret the percentage color sensor values
•Use the L2 and R2 sensors as well
CHALLENGES
7. Oval Race. Follow an oval line from start to finish. Time the run. The robot that does the quickest time wins.
8. RoboRAVE Line Follower Race. Be the fastest robot to get from home to the box.

19 | P a g e
H. SumoBot
SumoBots use the ultrasonic sensor to seek and destroy another robot vehicle in the Sumo ring, while using the color
sensor to sense the white border and avoid falling off the edge.
H1. Basic Sumo Code
The basic actions of a SumoBot are:
•A three second wait before doing anything
•Move forward from the edge 20cm
•Rotate until the ultrasonic sensor locates the other vehicle (less than 80cm away)
•Drive full speed toward the other vehicle
•If the white edge is detected (high reflectance value) then stop, back up and rotate to locate the other
vehicle

20 | P a g e
H2. Enhancements
•Only scan left and right up to 90 degrees the first time
•Stop every 10 degrees when scanning to make sure scan detects vehicle (moving too fast doesn’t work)
•Use movement sensor to detect a collision or the bot lifted off the ground (pitch or roll) and respond to that
(see Appendix 1)
•If motion is stopped for x seconds, use a series of rapid wheel movements (e.g. back and forth) to try and get
free
•Use a different strategy:
▪Follow white line around the outside (use L2 or R2)
▪Drive to a random place
▪Drive forward until white line and turn and randomly go somewhere else until white line
•Use more than one ultrasonic sensor at different angles