Adafruit feather main boards adafruit 2795 the adafruit feather 32u4 adalogger datalogger can form the core for your next data logging project with its built in sd card slot the atmel 32u4 is the big brother of the mcu thats been providing the arduino uno with its usb port for the last few years and its being used in the flora wearable boards running at 8mhz and 33v dc it has 32kbytes of flash memory and 2kbytes of ram and of course a native usb port compatible with the arduino idene