Datasheet

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

radio module

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

#7 - used as the radio GPIO0 / IRQ (interrupt request) pin.

#4 - used as the radio Reset pin

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

There are also breakouts for 3 of the RFM's GPIO pins (IO1, IO2 and IO3). You probably wont need these for most uses

of the Feather but they are available in case you need 'em!

Other Pins!

RST - this is the Reset pin, tie to ground to manually reset the AVR, 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!

https://learn.adafruit.com/adafruit-feather-32u4-radio-with-rfm69hcw-

module

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