Properties Of Pins Configured As Output - Intel Galileo User Manual

— 6 digital pins can be used as Pulse Width Modulation (PWM) outputs; they are
labeled with the ~ symbol. See
for details.
— The RX and TX pins control the programmable speed UART port.
• SCL and SDA pins control the I
TWI: A4 or SDA pin and A5 or SCL pin. TWI communication is supported via the
Arduino Wire library.
• AREF is unused. Providing an external reference voltage for the analog inputs is not
supported.
Note: It is not possible on the Intel
• 6 analog input pins (A0-A5):
— Each one of the 6 analog input pins provides 12 bits of resolution (that is, 4096
different values). By default, they measure from ground to 5 volts.
• 7 power pins:
— IOREF: The IOREF pin allows an attached shield with the proper configuration
to adapt to the voltage provided by the board. The IOREF pin voltage is
controlled by a jumper on the board, i.e., a selection jumper on the board is
used to select between 3.3 V and 5 V shield operation.
— RESET button/pin: Bring this line LOW to reset the sketch. Typically used to add
a reset button to shields that block the one on the board.
— 3.3V output pin: A 3.3 Volt supply generated by the on-board regulator.
Maximum current draw to the shield is 800 mA.
— 5V output pin: This pin outputs 5 V from the external source or the USB
connector. Maximum current draw to the shield is 800 mA.
— GND (2 pins): Ground pins.
— VIN: The input voltage to the Intel
power source (as opposed to 5 Volts from the regulated power supply
connected at the power jack). You can supply voltage through this pin, or, if
supplying voltage via the power jack, access it through this pin.
Note: The voltage applied to this pin must be a regulated 5 V supply, otherwise it
2.4.1

Properties of Pins Configured as OUTPUT

Pins configured as OUTPUT with pinMode() are said to be in a low-impedance state. On
®
the Intel
provided via an I
A0 to A5 can be configured as OUTPUT pins on the Intel
The I/O expander's pins, when configured as OUTPUT, can source (provide positive
current) up to 10 mA (milliamps) and can sink (provide negative current) up to 25 mA
of current to other devices/circuits. The individual per pin current sourcing capability of
10 mA is subject to an overall limit of 80 mA combined between all OUTPUT pins. The
per pin capability current sinking capability is subject to an overall limit of 200 mA. The
table below provides a breakdown of the overall OUTPUT capabilities of the pins.
®
Intel Galileo
Board User Guide
10
analog input range using the AREF pin and the analogReference() function.
could damage the Intel
Galileo Board, when a pin is configured as OUTPUT, the functionality is
2
C*-based Cypress I/O expander. Digital pins 0 to 13 and Analog pins
®
Intel Galileo Board—Details and Specifications
Section 2.4.2, "I/O Pin Mappings" on page 11
2
C* bus.
®
Galileo Board to change the upper end of the
®
Galileo Board when it is using an external
®
Galileo Board or cause incorrect operation.
®
Galileo Board.
March 2014
Order Number: 330237-001US