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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!

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.

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.

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 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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