Learn how to build the Elemento Labs Robo Car. Visit elementolabs.com to know more.

1. 5
MOTOR
ARDUINO MOTOR SHIELD
BASICS

2. What is a Motor ?
6
Motors convert electrical energy into
physical motion.
We want our Robots to perform actions
like moving, walking, lifting. All such ac-
tions require a motor. So lets learn about
them.
There are many types of motors.
Big ones, small ones, fast ones, strong
ones.
Whether you need brute strength, speed or delicate precision move-
ment, there is a motor designed for the task.

3. 7
Motors are classified as AC motor, or DC motors.
AC (Alternating Current) motors are rarely used in mobile robots
because most of the robots are powered with direct current (DC)
coming from batteries.
Also, since Arduino itself uses DC, it is more convenient to have the
same type of power supply for the motors as well. AC motors are
mainly used in industrial environments where very high power is
required.
A Direct Current, or DC, motor is the most common type of motor.
DC motors normally have just two leads, one positive and one nega-
tive.
If you connect these two leads directly to a battery, the motor will
rotate.
If you switch the leads, the motor will rotate in the opposite direction.

4. What is a Motor Shield ?
8
To control the direction of the spin of DC
motor, without changing the way that
the leads are connected, we use a com-
ponent called a motor shield.
Why do we need a motor shield ?
i.e. why can't we just connect the motors
to Arduino and start using them ?
Well, we need a motor controller in be-
tween the Arduino and motors because:
1. Voltage output from Arduino is just 5 Volts.
The Arduino needs that to power other electronic components. Hence
we cannot use Arduino as a power source to the motors.

5. 9
Thus, we need a motor shield which can take power from a
battery supply and in-turn supply power to our motors.
2. A motor is a complicated device. A motor shield simplifies the
wiring and use of motors. For example, the motor shield helps us in
reversing the direction of motors without soldering or complicated
wiring.
Motor shield acts as an intermediate device between Arduino,
batteries, and the motors.
Thus, although the Arduino (the robot’s brain) decides the speed and
direction of the motors, it cannot drive them directly because of its
very limited power (current and voltage) output. The motor shield, on
the other hand, can provide the current at the required voltage.

6. PROJECT 1
Build the Robo-car
10

7. 11
Project 1 : Build the Robo-car
What we are making
Lets build a Robo car from the parts shipped in this box !
This is how even a real world car is assembled - using motors, wheels,
chassis !

8. 12
Step 1:
Unwrap the paper over the
frame.
Peel both sides the acrylic
paper.
You can start from either side
top corner and work your way
down.
For this manual I will only
remove one side for ease in
visual demonstration

9. 13
Step 2:
Motor Mounting Brackets are used to fixed the DC motors to the frame.
Slide 2 brackets into the slot indicated in the red circle.

10. 14
Step 3:
Ensure the dot on motor is facing inwards. Shown with a red circle.
The red and black wire leads of motor will be facing outwards.
Insert two long
screws.

11. 15
Repeat all
above steps
for Motor 2
Step 4:
Step 5:
Fix the castor wheel as shown below. No screws are needed.
Note: You should skip this step if your chassis comes with a pre-fitted castor wheel.

12. 16Step 6:
Put a screw on chassis Fix the Spacer on top of screw
Repeat for remaining 3 spacers

13. 17
Step 7:
Fix the wheels on motor.
Apply pressure slowly as you push the wheels

14. 18
Step 8:
Place the
chassis cover
on top and fix it
using 4 screws
This step completes the assembling of the chassis.

15. 19Step 8:
Lets fix the Motor Shield on top of the Arduino.
DO NOT DAMAGE ANY PINS WHILE DOING THIS STEP.
Gently place the pins of
Motor Shield on top of
Arduino pin-holes.
Note that :
1. Arduino pin 0 is on
bottom right in this image.
2. SomeArduino pin-holes
will not be used.
Side view after fixing
Motor Shield.
Note the unused Arduino
pins marked in red circle.

16. 20Step 9:
Affix 5 hard-surfaced velcro
on the chassis
Affix 5 soft velcro on the backside
of Base - behind the Breadboard
Affix the Base on top of
chassis.
Make sure:
1. The wheels are not
touching the Base.
2. Breadboard is in front
of the car.

17. 21Step 10:
Affix 2 hard-surfaced
velcro for battery holder.
Affix 2 soft-surfaced
velcro on back of battery
holder. Then affix the
Battery holder on top of
the chassis.

18. 22
Step 11:
Take the red and black wires of
right side motor, and insert into M1
+ and GND slots in the Motor
Shield.
Take the red and black wires of left
side motor, and insert into M3 +
and GND slots in the Motor Shield.

19. 23
Step 12:
Take the Red and Black wires of the Battery holder, and insert into
power + and GND slots in the Motor Shield respectively.
Remember that Red wires are generally used to denote +,
while Black wires denote GND.

20. 24
A Note about Batteries:
1. Use good quality AA batteries like Duracell, as they give good
amperes and voltage to the motors.
2. Motors are power hungry, so remove the batteries from holder
when car is not in use.
Step 12:
Put 4 AA batteries (Duracell) in the holder.
BINGO !!
This completes the Robocar construction !

21. 25
Explanation:
We constructed the car using 2 motors. The power to the motors is supplied
by the Motor Shield.
The Motor shield itself gets the power from the 4 AA batteries.
Motors are a simple device - you supply power to them to make their shaft
spin. We attached our wheels to the motors, so that the wheels rotate
along with the motor shaft.
For the front part, we used a castor wheel.
A castor wheel is a special wheel that can turn in any direction.
No power needs to be supplied to a castor wheel.
Our Robo car is also called a 2 Wheel Drive Robo car - which means
that the car is driven by 2 motors.
Most real cars in the world are also 2 wheel drives where the back wheels are
connected to motors.