Datasheet

for the lipoly battery so be aware that this pin naturally 'sits' at around 2VDC due to the

resistor divider

#10 - GPIO #10

#11 - GPIO #11

#12 - GPIO #12

#13 - GPIO #13 and is connected to the red LED next to the USB jack

A0 - This pin is analog

input

A0 but is also an analog

output

due to having a DAC

(digital-to-analog converter). You can set the raw voltage to anything from 0 to 3.3V,

unlike PWM outputs this is a true analog output

A1 thru A5 - These are each analog input as well as digital I/O pins.

SCK/MOSI/MISO (GPIO 24/23/22)- These are the hardware SPI pins, you can use them

as everyday GPIO pins (but recommend keeping them free as they are best used for

hardware SPI connections for high speed and are shared with the BLE)

Bluefruit LE Module + Indicator LEDs

Since not all pins can be brought out to breakouts, due to the small size of the Feather, we

use these to control the BLE module

#8 - used as the Bluefruit CS (chip select) pin

#7 - used as the Bluefruit IRQ (interrupt request) pin.

#4 - used as the Bluefruit Reset pin

Since these are not brought out there should be no risk of using them by accident!