Datasheet

Other Pins!

RST - this is the Reset pin, tie to ground to manually reset the ATSAMD, as well as

launch the bootloader manually

ARef - the analog reference pin. Normally the reference voltage is the same as the chip

logic voltage (3.3V) but if you need an alternative analog reference, connect it to this

pin and select the external AREF in your firmware. Can't go higher than 3.3V!

DFU - this is the force-DFU (device firmware upgrade) pin for over-the-air updates to

the Bluefruit module. You probably don't need to use this but its available if you need

to upgrade! Check out the DFU Bluefruit Upgrades page for how to use it. Otherwise,

keep it disconnected.

SWD Pins

There's two sets of SWD pins. These are used for program/debug of the two processors on

the Feather.