A Feather board without ambition is a Feather board without FeatherWings! This is the Adalogger FeatherWing: it adds both a battery-backed Real Time Clock and micro SD card storage to any Feather main board. Using the Feather Stacking Headers or Feather Female Headers you can connect a FeatherWing on top of your Feather board and let the board take flight!
This FeatherWing will make it real easy to add datalogging to any of our existing Feathers. You get both an I2C real time clock (PCF8523) with 32KHz crystal and battery backup, and a microSD socket that connects to the SPI port pins (+ extra pin for CS). Tested and works great with any of our Feathers, based on ATmega32u4, ATSAMD21, or ESP8266.
We recommend the Arduino's default SD library to talk to the microSD card socket. On ESP8266, the SD CS pin is on GPIO 15, on Atmel M0 or 32u4 it's on GPIO 10. You can cut the trace to the default pin and change this to any pin. To use the RTC, use Adafruit's RTClib library.
Does not come with a micro SD card. A CR1220 coin cell is required to use the RTC battery-backup capabilities! We don't include one by default, to make shipping easier for those abroad, but we do stock them so pick one up or use any CR1220 you have handy. If you're not using the RTC part of the featherwing, a battery is not required.