This document provides an introduction to building and programming a simple EV3 robot. It describes starting with a base robot that has two motors and two sensors. The color sensor and gyro sensor are discussed as ways to help the robot navigate and sense its environment. Examples of simple programs are provided to demonstrate using the motors and sensors, including calibrating the color sensor. It is noted that programs may need to be adapted if the robot configuration is changed.

1. FLL Robasics
getting started with simple EV3 robotics

2. Robotics
● the branch of technology that deals
with the design, construction,
operation, and application of robots

3. Our “Base” Robot
Assumption: We’re all beginners at
● How Robotics Works (in general)
● Lego Mindstorm EV3 (specifically)
So let’s start simple...

4. Our “Base” Robot
● Pretty close to the one given in
the instructions that came with
the EV3 kit
● 2 motors (one per wheel)
● 2 sensors
○ gyro (upper left in this photo)
○ color sensor (will see later)

5. The undercarriage
● Note the location of
the color sensor
● This is important
o We will learn why later

6. “Base” Robot
● Starting with the same robot we can
o share programs, sub-programs
o learn the basic concepts
● We cannot
o develop full mission plans

7. Final Robot
● Robot will need additions / changes
o additional motors for arms, etc
o additional sensors
● Mission plans will dictate
o what your robot looks like
o consequently, your programs

8. Getting Started
● Get the Mindstorm software installed
● Add the gyro.ev3b block
o Not in the Home Edition
o But a free download (google it)
o tools -> block import
● Programming model is graphical

9. Connect your robot
● Connect via
bluetooth if possible
● once connected,
look at the motors
and sensors
connected

10. First Program!
What does it do?

11. Right face!
What does this do?
What is this 0.62 business?

12. Regular Quadrilateral
What about this?

13. Dead Reckoning
● We have a block that can control the motors of the
wheels in a natural way
o turn +/- 100%
o power 0-100%
o rotations or seconds
● We can chain these together as long as we
like!
● Great, we’re done, right? :-)
o Nope! We have to deal with the evil of error

14. Why did this program fail?

15. Sensors
● Gyroscope lets us trade “0.62” for something
more natural, more robust
● Gyro tells us the change in angle, which is
what we wanted anyway…
● But how do we use it?

16. Gyro “turn around” example...
353?
on until

17. Better Regular Quadrilateral

18. Other sensors
● Gyro is not perfect
o Helps avoid errors though
● Other sensors help in similar ways
● Color sensor lets us “see” landmarks
o Stop on color, follow edge
● We use multiple sensors to manage error...

19. Simple color sensor program

20. Calibration
The color sensor requires calibration…
● So black reports as “0”
● And white reports as “100”
● Otherwise hard to pick “good” numbers

21. This is the prog to calibrate color:

22. Pitfall!
● Sharing programs is great!
● But they are hardwired,
expecting specific motors on
specific {A,B,C,D}.
● And sensors on specific
{1,2,3,4}.
● Common copy/paste failure.

23. Original color calibration:
What’s wrong?