#7 - used as the MicroSD card CD (card detect) pin. If you want to detect when a
card is inserted/removed, configure this pin as an input with a pullup. When the
pin reads low (0V) then there is no card inserted. When the pin reads high, then
a card is in place. It will not tell you if the card is valid, its just a mechanical
switch
#8 - This pin was also left over, so we tied it to a green LED, its next to the SD
card. It might be handy to blink this LED when writing / reading valid data or
some other user-alert!
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!
Assembly
We ship Feathers fully tested but without headers attached - this gives you the most
flexibility on choosing how to use and configure your Feather
Header Options!
Before you go gung-ho on soldering, there's a few options to consider!
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©Adafruit Industries
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