Adafruit feather main boards adafruit 3027 the adafruit feather 32u4 fona is a microcontroller and mobile phone combo supporting gsm networking sms texts gprs data and fm radio in one tiny package 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 compatibl