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.

I use OpenLogs with GPS modules. No microprocessor. It sure would be nice if there was a clock inside that would name the files by their date. There's a 3 volt power supply chip on it. Can you make that a little easier to get at so we can power 3 volt things from it. Mechanically, there's no good way to mount the thing with double sticky. The flattest part of the device has springs which retain the SD card. Double sticky there is a problem.

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.

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.

• RTFM - read the flipping manual - really - once read and understood, it's a doddle to setup and run. I have 3 - all logging away merrily. Next step is to interpose switches inbetween the Rx / Tx pins of say an Arduino UNO to access remotely (a) data from the OPENLOG (b) also arduino to download program mods.

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.

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.

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.

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.

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 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!

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 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 .

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 tried the SPI based adapters, not nearly as useful as these. The SPI stuff is cheaper but they have speed limitations and must be buffered and carefully managed to avoid data loss.

The OpenLog is so simple, just connect it to your serial port and forget about it.

I've found that you can stream error free continuously at 57,600 baud with a class 10 card (10 MB/s), and 115,200 baud error free with a class 30 or v30 card (30 MB/s). Since I normally like to run my serial monitor at the latter rate, that is perfect for what I need.

Plus this only takes one IO pin (serial TX) vs. four for SPI, and the adapter is about the size of a postage stamp. Level shifting is optional, only needed for reads but should really work fine without it (plus I don't do reads anyway, do that later from my laptop).

I plan on putting an OpenLog on all my bots from now on. =)