SparkFun OpenLog Open-source data logger works over a simple serial connection Supports microSD FAT16/32 cards up to 32GB Configurable baud rates up to 115200bps Preprogrammed ATmega328 and bootloader

This is a great little device for logging serial output from a microcontroller. Just connect to the UART and it's preprogrammed to record output. I'm using it to record sensor output to an SD card. The firmware can be customized as needed, but I just used the firmware it shipped with.

The logger is great when it works, however the mechanism that holds the SD card in place is extremely fragile and does not last long, I've ordered more than 10 over the past couple of weeks and every single one broke within a couple of days of continuous use. Can not recommend.

Only for technicians. It sits in a drawer unopened. No idea how to use it.

This little board is great. In only a couple hours I had it logging serial data from my Arduino to an SDCard. I started to follow the instructions from SparkFun to download a new program to it via an FTDI interface adapter, but I realized soon enough that the built-in program was all I needed so I can use it right out of the box. YOu can directly connect the TX/RX pins to their mating RX/TX pins on an Arduino (or any other TTL serial data stream and it captures the data to a LOG file on the SDCard automatically.I only wish for a clock/cal to time stamp the logs, and the ability to run faster than 9600 baud without worry of missing data. For the price, size and performance...It's GREAT!

In typical SparkFun fashion, this OpenLog has great documentation on their website. I was up and running in minutes. Everything on the board is pretty self-explanatory--there's helpful labels on all the pins. The LEDs were also a nice touch, so you know if it's working at a glance. Overall the performance has been great, and it had no trouble keeping up with data-logging at 115200 baud.This would've been a perfect product were it not for the SD card socket, which felt quite flimsy. My suspicions were confirmed when it broke after a couple of insertions and no longer held onto cards. Fortunately, SparkFun's customer service helped me find a replacement part in short order.In summary, this is a great compact way to add serial data logging to your project, although some improvements could be made in durability.

I use this to log debug output of devices in the field so that I don't have to be present to collect the data. I only have two minor issues that users should be aware of. First, it can't start logging after power up for a little over 1 second. Second, it doesn't seem to be able to keep up with a steady 115200 baud stream. I think this is affected by the SD card speed; but have not used any cards that allow full 115200 baud speed. Otherwise, it is pretty much plug and play as long as you have a TTL level serial connection. It seems that the Sparkfun's version is reliably flashed to operate out of the wrapper. Not like I have read about other vendor's versions.

Love these things, we’re used for an investigation to measure the debugging interface of a product. I modified firmware to include a serial TX message to initial the debugging interface on the product so it would start transmitting data. Just be careful when you remove the SD cards to avoid corruption

During the 3rd insertion of an SD card there was an audible click, and the SD card would hold no more. I now have to wrap a zip tie around the logger to hold the card in. Very cheap quality.