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 divider outputs a voltage equal to two-thirds of the battery voltage, which will always be safely below the Arduino’s maximum analog input voltage of 5 V. For example, at a battery voltage of 4.8 V, analog pin 1 will be at a level of 3.2 V. Using Arduino’s
unsigned int batteryVoltage = analogRead(1) * 5000L * 3/2 / 1023;
If you have an Arduino Uno or an older Arduino (with an ATmega328P or ATmega168 microcontroller), you should jumper the two holes bracketed with the label 328P to connect the BZ pin to digital pin 3. If you have an Arduino Leonardo (with an ATmega32U4 microcontroller), you should jumper the two holes bracketed with the label 32U4 to connect the BZ pin to digital pin 6. These are the pins our ZumoBuzzer library expects the buzzer to be connected to for each respective microcontroller. More details about the buzzer can be found in Section 3.a.
On the Arduino Uno R3, SCL and SDA are duplicates of analog pins 5 and 4, respectively. On the Arduino Leonardo, SCL and SDA are duplicates of digital pins 3 and 2, respectively. Using the I²C sensors on the shield will prevent these pins from being used for other purposes, and the I²C pull-up resistors will affect readings on these pins even if the compass is not being actively used, so you must cut the jumpers to disconnect the inertial sensors and pull-ups if you want to repurpose the SCL and SDA pins.
Please note that the SCL and SDA pins do not exist on Arduino hardware versions prior to the Uno R3, so you will have to manually connect SCL to analog pin 5 and SDA to analog pin 4 on the Zumo Shield in order to use the compass with an older Arduino. The most convenient place to do this is in the front expansion area, where these pins are all located together, as indicated by the light blue boxes in the picture above.
More details about the inertial sensors can be found in Section 3.d.
Instead of making a wire connection, you can solder a 1×3 male header to the buzzer control jumper holes to allow the use of a shorting block for connecting the buzzer (note: this header is already installed if you got the assembled version of the Zumo robot, but the shorting block must be positioned in the appropriate place for the Arduino model you are using). 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 to use male headers on the battery level and compass I²C jumpers if you are using an Arduino with a DIP (through-hole) microcontroller.