If you use an Arduino Uno R2 or an older Arduino, which lack separate I²C pins, the SDA and SCL pins on the
Zumo Shield will not be connected to anything. To use an I²C device on those pins, you can connect SDA to A4
and SCL to A5 yourself by bridging across those two sets of pins in the front expansion area.
further
explains the I²C lines and the jumpers connecting them to the onboard compass module.
Depending on the Arduino model, digital pin 3 or 6 is used to control the buzzer if you install the
buzzer control jumper. If you are using an Uno, pin 6 will be available for general-purpose I/O.
If you are using a Leonardo, pin 3 will be available if you are not using I²C. These pins are not
accessible via the front expansion, but they can be accessed from other points on the shield and
used for interfacing with additional electronics if free. Additionally, digital pin 12 can be used for
interfacing with many types of additional electronics, especially if you are not using the shield’s
user pushbutton. Pin 12 is completely free when the pushbutton is in its default, unpressed state,
and it is pulled low through a 1k resistor when the pushbutton is pressed.
3.c. Jumper settings
The Zumo shield has several jumpers that let you change the way it is connected to the Arduino, as shown in the
picture below.
• The
battery level jumper
connects the Arduino’s analog pin 1 to a voltage divider circuit that allows
you to monitor the Zumo’s battery voltage. This jumper is disconnected by default and can be connected by
soldering a short length of wire between the two holes.
Pololu Zumo Shield for Arduino User's Guide
© 2001–2012 Pololu Corporation
3. The Zumo Shield in detail
Page 19 of 28
