This Product Has Been Discontinued, This Page Is For Reference Only.

24.95 USD
$24.95 ea.
$22.46 ea.

OpenLog is an open source data logger. Simple to use, simple to change.

Description [Hide]

Superceded by Sparkfun's DEV-13712

SparkFun doesn't mess around when they have something they want to make happen. There's been too many projects needing a simple, effective serial datalogger, so hence: The OpenLog - an open source data logger!

The OpenLog is a serial logger that just works. Power it up and it will starts logging any received serial data at 9600bps. Sending Ctrl+z will drop out of logging and in to command mode. 'new' will create a new file. 'md' makes a directory. '?' brings up the list of commands. OpenLog doesn't do everything, but it does log serial streams extremely well. Here's an example of how it is used:

>new testfile.txt
>append testfile.txt

That's it! OpenLog firmware is open source and is based on Roland Riegel's FAT library. OpenLog currently supports FAT16 (up to 2GB microSD cards). (FAT32 work is underway - stay tuned... or help!)

All the design files (schematic, PCB layout, firmware) are open source released under the CC-SA v3 license and are available through Github.

The SparkFun 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 SparkFun 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.


  • 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



Documentation [Hide]

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