The SparkFun OpenLog is an open source data logger. Simple to use, simple to change. We wanted to create a serial logger that just worked. Power up this device and it will start logging any received serial data at 9600bps. Sending Ctrl z three times 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 a lot, but it does log serial streams extremely well. Example:

 >new testfile.txt   >append testfile.txt   <(send large amounts of text followed by three ctrl z characters)

That’s really it! OpenLog firmware is open source and is based on Bill Greiman’s . OpenLog currently supports FAT16 and FAT32 microSD cards (we’ve tested up to 64GB!).

All the (schematic, PCB layout, firmware) are open source released under the license and are available through .

Note: New firmware is available which allows the OpenLog to be used in Arduino 1.0 and also allows for higher baud rates. Check the links below for more information.

Features:

• Log to low-cost microSD FAT16/32 cards up to 16GB
• Simple command interface
• Edit config.txt file from a computer to change baud rate and other system settings
• Three modes:
  • NewLog creates a new log every power up and immediately starts logging
  • SeqLog appends a file called “SeqLog.txt” at every power up and immediately starts logging
  • Command mode starts OpenLog at a command prompt at power up
• Configurable baud rates (2400 to 115200bps)
• Configure unit through config file or the menu system
• Power, ground, and RX-I are the minimum connections
• Reprogrammable ATmega328 using the Arduino IDE
• Two LEDs indicate writing status
• Input voltage from 3.3V to 12V
• 2mA idle, 6mA at maximum recording rate

Dimensions: 0.16 x 0.6 x 0.75" (4 x 15 x 19mm)

Documents:

• Illumitune Project () ()
• (for latest code, issues, and documentation)

The OpenLog project is housed on GitHub! Please see the for the most up-to-date firmware, feature requests, files, and datasheet specs.

Accessories