Ioref Jumper; I2C* Address Jumper; Jumper Locations - Intel Galileo User Manual

Details and Specifications—Intel
Figure 4.

Jumper Locations

2.5.1

IOREF Jumper

To support both 3.3 V and 5 V shields, the external operating voltage is controlled via a
jumper.
• When the jumper is connected to 5 V, the board is configured to be compatible with
5 V shields and IOREF is set to 5 V.
• When the jumper is connected to 3.3 V, the board is configured to be compatible
with 3.3 V shields and IOREF is set to 3.3 V.
The input range of the Analog pins is also controlled by the IOREF jumper and must not
exceed the chosen operating voltage. However, the resolution of AnalogRead() remains
at 5 V/1024 units for the default 10-bit resolution or, 0.0049 V (4.9 mV) per unit
regardless of IOREF jumper setting.
Warning: The IOREF jumper should be used to match the board and shield operating voltages.
Incorrectly setting the voltage could damage the board or the shield.
2
2.5.2 I C* Address Jumper
To prevent a clash between the I
EEPROM with any external I
address of the on-board devices.
With J2 connected to pin 1 (marked with white triangle), the 7-bit I/O Expander
address is 0100001 and the 7-bit EEPROM address is 1010001.
Changing the jumper position changes the I/O Expander address to 0100000 and the
EEPROM address to 1010000.
March 2014
Order Number: 330237-001US
®
Galileo Board
2
C* Slave address of the on board I/O expander and
2
C* Slave devices, jumper J2 can be used to vary the I
2
C*
®
Intel Galileo
Board User Guide
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