The SparkFun OpenLog is an open source data logger that works over a simple serial connection and supports microSD cards up to 32GB. 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 uses an ATmega328 running at 16MHz thanks to the onboard resonator. The OpenLog draws approximately 2-3mA in idle (nothing to record) mode. During a full record OpenLog can draw 10 to 20mA depending on the microSD card being used.
All data logged by the OpenLog is stored on the microSD card. Any 512MB to 32GB microSD card should work. OpenLog supports both FAT16 and FAT32 SD formats.
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Skill Level: Noob - Some basic soldering is required, but it is limited to a just a few pins, basic through-hole soldering, and couple (if any) polarized components. A basic soldering iron is all you should need.
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Skill Level: Rookie - You will need a better fundamental understand of what code is, and how it works. You will be using beginner-level software and development tools like Arduino. You will be dealing directly with code, but numerous examples and libraries are available. Sensors or shields will communicate with serial or TTL.
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If it requires power, you need to know how much, what all the pins do, and how to hook it up. You may need to reference datasheets, schematics, and know the ins and outs of electronics.
Skill Level: Rookie - You may be required to know a bit more about the component, such as orientation, or how to hook it up, in addition to power requirements. You will need to understand polarized components.
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Based on 20 ratings:
3 of 3 found this helpful:
Purchased two for research project. Wired them up to device and worked perfect with stock firmware. After two-three insert/ejections of the microsd card the mount failed to hold the card. When you insert the card it just springs right out. Rewired a second one up and had the same thing happen. Both units worthless. After inspection there is a tiny hooked wire that rides in a plastic groove to lock and unlock the microsd card. The plastic is so soft that after a couple of inserts the groove no longer functions properly.
1 of 1 found this helpful:
One of the best modules I ever used. It has all the good features, small, large capacity, simple interface, low price, great documentation, low power, and open source. Need to be considerate of data rate for the higher speed applications. Highly recommend for any data storage project. Worked first time following Sparkfun great hookup guide.
2 of 2 found this helpful:
I had been having some intermittent connection problems with a custom esp8266-based board. Devices that were further out from a router would sometimes lose their connection, reset, but then fail to reconnect. I had no way to capture debugging logs while deployed and very limited I/O to add anything else to the board for this purpose.
The OpenLog really fit the bill nicely here. It could reuse the serial TX/RX lines while deployed, so all I had to do was find a reset line. After some trial and error, I found resetting the OpenLog at esp init time was essential for stable operation. In addition, I added some code to check to see if the OpenLog is plugged in and to set the baud rate appropriately, 9600 w/ OpenLog, 115200 for console.
I'm very happy with what I ended up with. $15 for OpenLog, $6 for an SD card, and now I can get logs while the system is deployed.
1 of 1 found this helpful:
This is a great little SD card reader/writer. The sample code software is very sparse. I had to write much more elaborate code to make this logger useable and it took some time and experimentation to get it right.
Easy to use and it just works! Also, you can program it like an arduino pro mini; I just wish it had a couple of DIO pins broken out (in addition to tx and rx).
I'm agreeing with review by Member #670407. We use this component in a couple different devices and when you take the SD card out more than a few times and aren't extremely gentle, the spring seems to break. Would love to see a rev that makes it more hardy. Thank you.
I bought mine to use in a museum ticket printer. The printer not only prints tickets it keeps track of the number and type of visitors to the museum and stores the data and the card. I used a pickax processor, and had no problems at all.
I am building a research payload for a community called ANSR of which I am a member. This devices works with no problem with the BASIC Stamp Microcontroller I use to record sensor data. Overall, never had any problems to this date and is extremely easy to use.
Very simple to setup out of the box. I connected to GPS-13740 GPS Receiver - GP-20U7. I got the idea from instructibles.com and so for just over $35 for GPS and logger I have a cool GPS Logger. I can upload the data to Google Earth and see a visual track of where it's been. Fun for boating, hiking, etc.
Doing a perfect job of recording the outputs of several different small GPS receivers and weighs so little that it doesn't load airplane very much.
I have a complaint. The unit has far more capability than is in .config file when delivered and a reference to a simple setup program would sure be welcome.
I connected this device to a simple 3.3V uart on a mobile device I am testing. My device had a wire supplying 3.3V so the installation was a snap. It works simply - just put in a microSD card and the OpenLog will create a "config.txt" file. Edit this file on the card using a computer to set the baud rate for your device. This allowed me to remotely capture days of serial logs from my test device. Note that microSD cards >16GB capacity are not easily formatted in the necessary FAT32 file type. But 16GB is a lot of capacity for my application.
I needed a way to log data from a series of tests in a lab that cannot use a PC/laptop. I tried for a month to get Chan's FatFS USB stack to work without any success. Then I found this. Great little module.
2 things I recommend to Sparkfun engineers:
1 - Make a copy of this that allows data to be logged to USB thumb drive.
2 - update design to use normal SD card rather than these ridiculously small micro sd cards.
Easy to use and this page gives instructions: https://learn.sparkfun.com/tutorials/microclimate-kit-experiment-guide/experiment-7-logging-to-the-microsd-card
(Please note that the code on the page does not correspond to the text on the page. There is no Press Button A and the display is blank.) I added a "show string row" line so the display would show something and you can tell it's working.
No trouble getting the logger up and running with command mode off, which is what I needed, bare bones data logging. However it would have been really nice to be able to do file management with the same code, but switching between reading and writing is not supported, or at least there's not a clear way to accomplish it. On the next OpenLog version there should be a PIN or other means to toggle the functionality.
I've only played with this enough to get it going to know that it works with my micro:bit .
0 of 1 found this helpful:
I love this idea ...
In it's current form it has a 1000 and one uses ... but I wish there was a version with a barrel power connector and DB9 male connector.
I have used this in several professional test situations, and it hasn't let me down. You can just connect and go, or with some more involved commanding you can take advantage of the file operations to organize your data as you collect it. The only thing that I struggled with is the fact that the command mode needs carriage returns rather than line feeds, which caused me several hours of flailing before I could get the file operations to work. It would be nice if that were configurable in the micro-SD config file.
I was able to reliably log a stream of approx. 20 chars/record at 200 recs/sec using 57.6k interface. Using arduino pro mini. Very handy!