Pololu Zumo User manual

Pololu Zumo Shield for Arduino
User's Guide
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.a. Contacting Pololu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.b. Included components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.a. What you will need . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.b. Assembling the Zumo Shield and chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. The Zumo Shield in detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.a. Features and components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.b. Front expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.c. Jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.d. 3-axis compass module (accelerometer and magnetometer) . . . . . . . . . . . . . . . . . . . . . . 20
4. Schematic diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5. Arduino pin assignment table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6. Zumo Shield Arduino Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7. Example project: Border-detecting sumo robot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.a. Adding QTR reflectance sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.b. Arduino sketch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Pololu Zumo Shield for Arduino User's Guide © 2001–2012 Pololu Corporation
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1. Overview
The Zumo Shield provides a convenient interface between our Zumo chassis [http://www.pololu.com/catalog/product/
1418] and an Arduino Uno [http://www.pololu.com/catalog/product/2191] or Leonardo [http://www.pololu.com/catalog/
product/2192] (it is not compatible with the Arduino Mega or Due, but it can be used with older Arduinos that have
the same form factor as the Uno, such as the Duemilanove). The shield mounts directly to the chassis, connecting
to its battery terminals and motors, and the Arduino plugs into the shield’s male header pins, face down. The
shield provides all the electronics necessary to power the motors and includes some additional fun components
for making a more interesting robot, such as a buzzer for making sounds and a 3-axis accelerometer and compass.
Zumo Shield for Arduino. Assembled Zumo robot with a Zumo
Shield, Arduino Uno, and Zumo blade.
A Zumo chassis, Zumo Shield, and Arduino can be combined to become a low-profile, Arduino-controlled
tracked robot that is less than 10 cm on each side (small enough to qualify for Mini-Sumo competitions).
Zumo Shield for Arduino, labeled top
view.
Zumo robot assembled with a Zumo
Shield and Arduino Uno, back view.
The Zumo Shield is available by itself [http://www.pololu.com/catalog/product/2504] or as part of a Zumo robot kit
for Arduino [http://www.pololu.com/catalog/product/2505] that also includes a Zumo chassis and a stainless steel Zumo
blade [http://www.pololu.com/catalog/product/1410].
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1. Overview Page 2 of 28

Fully assembled Zumo chassis
with assembled Zumo Shield.
1.a. Contacting Pololu
We would be delighted to hear from you about your experiences with the
Zumo Shield for Arduino [http://www.pololu.com/catalog/product/2504] or
Zumo robot kit for Arduino [http://www.pololu.com/catalog/product/2505]. If
you need technical support or have any feedback you would like to share,
you can contact us [http://www.pololu.com/contact] directly or post on our
forum [http://forum.pololu.com/viewforum.php?f=29]. Tell us what we did well,
what we could improve, what you would like to see in the future, or
anything else you would like to say!
1.b. Included components
The Zumo Shield is available by itself [http://www.pololu.com/catalog/product/
2504] or as part of a Zumo robot kit for Arduino
[http://www.pololu.com/catalog/product/2505] that also includes a Zumo
chassis [http://www.pololu.com/catalog/product/1418] and a stainless steel Zumo blade [http://www.pololu.com/catalog/
product/1410].
Zumo Shield
The shield itself comes with the following
components:
• right-angle slide switch
• two pushbuttons [http://www.pololu.com/catalog/
product/1400]
• buzzer
•2-pin battery-charging header
[http://www.pololu.com/catalog/product/1012]
• three jumper wires (for soldering motors to the
chassis)
• 40-pin 0.1″ straight breakaway male header
[http://www.pololu.com/catalog/product/965]
• two blue shorting blocks
[http://www.pololu.com/catalog/product/968]
• two 5/16″ #2-56 machine screws (to be used instead of the 1/4″ screws included with the chassis kit if you
attach a Zumo blade)
• 1/16″ black acrylic spacer plate (two pieces)
Zumo Robot Kit for Arduino
In addition to the shield and its included hardware, the Zumo robot kit for Arduino also includes these
components:
Pololu Zumo Shield for Arduino User's Guide © 2001–2012 Pololu Corporation
1. Overview Page 3 of 28

•Zumo chassis kit [http://www.pololu.com/catalog/
product/1418], which includes:
◦ Zumo chassis main body
◦ 1/16″ black acrylic mounting plate (not used
with the Zumo Shield)
◦ Two drive sprockets
◦ Two idler sprockets
◦ Two 22-tooth silicone tracks
◦ Two shoulder bolts with washers and M3 nuts
◦ Four 1/4″ #2-56 screws and nuts
◦ Battery terminals
•Basic sumo blade for Zumo chassis
[http://www.pololu.com/catalog/product/1410]
You will receive the black acrylic spacer and mounting plates with protective paper masking on
both sides. You can peel this masking off to expose the acrylic surface, or you can leave it on to
increase the thickness of the plates.
The shield and chassis kit include extra parts like jumper wires, screws, nuts, and washers, so do
not be concerned if you have some leftover hardware after assembling your Zumo.
Pololu Zumo Shield for Arduino User's Guide © 2001–2012 Pololu Corporation
1. Overview Page 4 of 28

2. Assembly
2.a. What you will need
The Zumo Shield is designed to be mounted on a Zumo chassis kit [http://www.pololu.com/catalog/product/1418],
which is included (along with a Zumo blade [http://www.pololu.com/catalog/product/1410]) if you have a Zumo robot
kit for Arduino [http://www.pololu.com/catalog/product/2505]. In addition, you will require these items to construct a
working Arduino-controlled Zumo robot:
Additional required components
• Two micro metal gearmotors [http://www.pololu.com/catalog/category/60] (we recommend 100:1
[http://www.pololu.com/catalog/product/1101] or 50:1 [http://www.pololu.com/catalog/product/998] gear ratio versions
with HP motors)
• An Arduino (we recommend an Uno R3 [http://www.pololu.com/catalog/product/2191] or a Leonardo
[http://www.pololu.com/catalog/product/2192])
• Four AA batteries (we recommend rechargeable AA NiMH cells [http://www.pololu.com/catalog/product/1003])
Please see the product description for the chassis kit [http://www.pololu.com/catalog/product/1418] for more
information and recommendations about selecting these components.
Additional optional components
•Basic sumo blade for the Zumo chassis [http://www.pololu.com/catalog/product/1410]
•Sensors [http://www.pololu.com/catalog/category/7], such as our QTR reflectance sensors
[http://www.pololu.com/catalog/category/123]
•Connectors and jumper wires [http://www.pololu.com/catalog/category/19], for connecting additional sensors
and components
• Battery charger (such as the iMAX-B6AC [http://www.pololu.com/catalog/product/2260]), if you are using
rechargeable batteries
Assembly tools
• Soldering iron and solder (we recommend one with adjustable temperature control)
• Wire cutter
• Small Phillips screwdriver
• 3 mm Allen wrench (hex key)
• long-nose pliers (for bending the Zumo blade mounting tabs)
2.b. Assembling the Zumo Shield and chassis
Please follow these instructions carefully to assemble your Zumo Shield and chassis properly.
Pololu Zumo Shield for Arduino User's Guide © 2001–2012 Pololu Corporation
2. Assembly Page 5 of 28

Through-hole parts
1. Solder the included through-
hole components to the shield:
◦ power switch
◦ reset pushbutton
◦ user pushbutton
◦ buzzer
◦ charging connector
(1×2-pin female header)
2. On the bottom of the board,
trim any leads longer than 1/16″
(the thickness of the spacer plate)
so they do not prevent the shield
from sitting flat on the spacer
plate and chassis.
Arduino headers
3. Separate the 1×40-pin
breakaway male header into the
appropriate segments for
connecting your Arduino and
solder them to the shield. These
header segments should be
soldered to the sets of holes
outlined with white rectangles on
the top of the shield, with the pins facing up.
The newest Arduino boards, including the Uno R3 and the Leonardo, use one 1×10 header, two 1×8 headers, and
one 1×6 header; older Arduino boards use two 1×8 headers and two 1×6 headers (the two pairs of pins highlighted
above in red should not be populated if you are using this board with an older Arduino that does not support these
additional pins). Please make sure you solder the appropriate headers for your particular Arduino!
An easy way to line up the Arduino headers for soldering is to plug them into an Arduino, then place the shield
upside-down on top of them, as shown in the picture below. Be careful to insert the header pins into the correct
set of holes before you begin soldering. Note: if you use this alignment technique, make sure your soldering iron
temperature is not excessively hot and avoid holding the iron on a single pin for more than a few seconds as this
could melt the Arduino’s female headers.
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4. On the bottom of the board, trim the four Arduino header pins closest to the front of the board on each
side to prevent them from contacting the motor housings. If you think there is a chance these pins might still
touch the motor cases, you can put some electrical tape on the motors to act as insulation.
Jumpers and additional connections
5. Optional: If you want to enable the buzzer, enable the battery level input, or disable the compass, now is
a good time to add and/or cut jumper connections to configure the shield to your liking. This can also be done
later, though soldering to these pins is more difficult once the robot is assembled (especially if you decide
later you want to add header pins for use with shorting blocks; this would require a lot of disassembly). The
jumpers are explained in detail in Section 3.c. The buzzer and battery level jumpers can be connected by
soldering in a short piece of wire between the two holes, while the compass I²C connections can be broken by
cutting the trace on the top of the board between the holes. Note: there is not enough clearance to use male
headers on the battery level and compass I²C jumpers if you are using an Arduino with a DIP (through-hole)
microcontroller.
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Instead of making a wire connection, you can solder a 1×3 male header to the buzzer jumper holes
to allow the use of a shorting block for connecting the buzzer. You can also use male headers and
shorting blocks for the battery level jumper and compass jumpers if you have an Arduino Leonardo
or an Arduino Uno with an SMD (surface mount) microcontroller. However, there is not enough
clearance to use male headers on the battery level and compass I²C jumpers if you are using an
Arduino with a DIP (through-hole) microcontroller.
6. Optional: At this point, you might consider soldering additional components (such as sensors), or
headers or wires for connecting them, to the shield. If you do this, please check to make sure your part
placement does not interfere with the shield’s ability to mate with the Arduino or the chassis. In particular,
note that only components in the outermost three rows of the front expansion area can extend below the
board (the fourth front-expansion row can only be used for pins extending above the board), and if you add
any through-hole parts to the prototyping areas on the shield, you will need to drill corresponding holes in
the acrylic spacer plate for the leads to fit into.
Motors
7. Cut two of the included jumper wires in half to form four segments, and trim off the ends that are covered
in adhesive (the adhesive could interfere with making a good electrical connection to the motor). These wire
segments will be used as motor leads.
8. Solder a pair of leads to each motor. You might find it helpful to make a small bend at the tip of each lead
to hook into the hole in the motor lead tab to hold it in place for soldering. Warning: holding the soldering
iron against the motor lead for more than a few seconds can start to damage the motor brushes, so try to be
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2. Assembly Page 8 of 28

reasonably quick/efficient with this soldering; if the first attempt does not go well, remove the soldering iron
and let the motor cool for a few seconds before trying again.
Each motor’s positive terminal is indicated by a plus sign (+) in the black plastic end of the motor, visible at the
bottom of the picture above. The motors should be soldered into the shield with the positive terminal closest to
the front, so you should attach the leads to allow the motors to be oriented this way. (However, don’t worry if you
accidentally get the orientation of one or both motors wrong. You can later compensate for it in software with our
ZumoMotors library [http://www.pololu.com/docs/0J57/6].)
9. Place the motors into the channel in the front of the chassis, aligning the gearbox with the grooves in the
channel. The front plate of the gearbox should be even with the edge of the chassis.
Pololu Zumo Shield for Arduino User's Guide © 2001–2012 Pololu Corporation
2. Assembly Page 9 of 28

Chassis and shield
To assemble the chassis with the Zumo Shield, you should use the two-piece acrylic spacer plate
that is included with the shield. You will not need the one-piece mounting plate that is included
with the Zumo chassis.
10. Place an M3 nut in each of the two side slots near the rear of the chassis. The slots are sized so that nuts
will not be able to rotate within them. (These nuts will be used to mount the idler sprockets later.)
11. If you want, peel the protective paper masking off both sides of the acrylic spacer plate pieces (the
spacer plates in our pictures show what they will look like with the masking peeled off). Alternatively, you
can leave the masking on for additional thickness. If you leave the masking on, it will be mostly concealed
when the robot is fully assembled.
12. Cover the chassis and motors with the spacer plate pieces and then the Zumo shield. The holes in the
spacer plate should line up with the through-holes in the shield resting on top of it. There is only one correct
orientation for these plates. (The plate consists of two separate pieces to make it possible to disassemble the
Zumo without having to desolder the motors or battery terminals.)
13. In each of the four mounting holes, insert a #2-56 machine screw through the shield, spacer plate, and
chassis, and tighten it against a nut under the chassis. You can line up the nut by feel, or you could try
temporarily taping the nuts inside the recesses in the chassis. Note that the kit includes two different sizes of
#2-56 machine screws: 1/4″and 5/16″. The two longer screws are intended for use in the front holes (near the
motors) if you are also mounting a sumo blade; otherwise, you can use the shorter 1/4″ screws for all four
mounting holes.
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