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OpenLog – Open source data logging

OpenLog is a simple serial logger based on the ATmega328 running at 16MHz. The ATmega328 is able to talk to high capacity (larger than 2GB) SD cards (but requires a recompile and reflash). The whole purpose of this logger was to create a logger that just powered up and worked. OpenLog ships with the standard (stk500v1) serial bootloader so you can load new firmware with a simple serial connection.

I just want it to work : Go to the product page and buy OpenLog. We pre-program the device with latest firmware.

I just want to use it : Just power up OpenLog and by default (in v1.1 and above) OpenLog will log any serial text thrown at it. No commands, no configuration required. Just power up and go!

How do I change the baud rate to 57600bps? : On versions 1.6 and above, the easiest way is by editing the CONFIG.txt and change 9600 in the text file to 57600. More information is available on the command set page. If you have a previous version of the firmware (1.51 and below) you can easily change the baud rate from the baud system menu through the command prompt.

I don’t know what baud rate I put it into! Help! : (RTFM) If you get OpenLog stuck into an unknown baudrate, there is a safety mechanism built-in. Tie the RX pin to ground and power up OpenLog. You should see the LEDs blink back and forth for 2 seconds, then blink in unison. Now power down OpenLog and remove the RX/GND jumper. OpenLog is now reset to 9600bps. The escape command is reset to ctrl+z sent consecutively three times.

What are the commands I can use? : The command set is available here. You can find the datasheet here.

Known Issues : Please see the Issues tab up above.

I’ve got an OpenLog but it seems to have an older version of firmware. How do I get the latest features? : See How to upgrade the firmware.

Where do I find what version of firmware my OpenLog has? : From the command prompt type ‘?’. This will bring up the help menu. The firmware version is displayed at the top of the menu.

So what is this place? : This is the where the firmware is hosted so that users can download, modify, and give back improvements to the firmware.

How do I use GitHub with Windows? : We’ve written a step by step tutorial for Windows users on how to use TortoiseGit.

How can I help? :

  • Play with OpenLog
  • Find problems
  • Suggest improvements
  • Fix them

One of the main reasons we created OpenLog was because we saw microSD cards (we call them SD cards from now on) dropping in price and increasing in size. NewEgg currently has 8GB cards for ~$16. This is phenomenally cheap, but any card larger than 2GB requires SDHC support to be enabled and to actually go beyond 2G in one partition requires FAT32 support from the logger. Note FAT16 with SDHC is not stable in the current version. As SD cards continue along this trend, FAT16 compatible cards are increasingly hard to find. Roland Riegel has written support for FAT32 but it is not yet functional on the OpenLog.

Please help us with the documentation! We’d like OpenLog to be as easy to use as possible. If you’re familiar with how OpenLog works, help us by contributing issues, recommending code improvements, or add to the documentation.

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