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How, exactly, you power your project is up to you and the demands of your
project. If you’re making something battery powered, you may want to opt
for the 3.3V Pro Micro, which could be powered by a LiPo battery or a
couple alkalines.
Hardware Overview: Fio v3
On this page we’ll examine the hardware half of the Fio v3, looking at the
pinout, layout, and schematic of the board.
The Fio v3 is like an elongated Pro Micro. On one end, it’s shape and
pinouts are similar to it’s ATmega32U4 sibling. The other end of the Fio v3
is what makes it unique: a footprint for an XBee on the bottom, and a LiPo
charging circuit on the top.
The Pinout
All of the Fio v3’s pins are broken out to either side of the board. Some pins
are for power input or output, other pins are dedicated I/O pins. Further, the
I/O pins can have special abilities, like analog input, or serial input/output.
Here’s a map of which pin is where, and what special capabilities it may
have:
Power Pins
The pins labeled ‘
3.3V
’ break out the operating voltage source of the
ATmega32U4. As long as the board is powered through the white JST
connector or USB, this voltage is
regulated
down to 3.3V. These pins can
be used as
outputs
to supply 3.3V to other devices.
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