The OpenLog is an open source data logger that works over a simple serial connection and supports microSD cards up to 64GB.
The OpenLog can store or "log" huge amounts of serial data and act as a black box of sorts to store all the serial data that your project generates, for scientific or debugging purposes.
The OpenLog runs off of an onboard ATmega328, running at 16MHz thanks to the onboard crystal.
The OpenLog draws 6mA when recording a 512 byte buffer, but as that process takes a fraction of a second, the average current draw is closer to 5mA. Keep in mind though that if you are recording a constant data stream at 115200bps,
you will approach that 6mA limit. All data logged by the OpenLog is stored on the microSD card that involve the features of 64MB to 64GB capacity and FAT16 or FAT32 file type.
Note: The latest version of the firmware (included with this board) does not compile in Arduino 1.6.7. You will need to compile in 1.6.5.

Features:
VCC Input: 3.3V-12V (Recommended 3.3V-5V)
Log to low-cost microSD FAT16/32 cards up to 64GB
Simple command interface
Configurable baud rates (up to 115200bps)
Preprogrammed ATmega328 and bootloader
Four SPI pogo pins
Two LEDs indicate writing status
2mA idle, 6mA at maximum recording rate

Package included：
1 x Serial Data Logger Open Source Data Recorder for Openlog