SparkFun will be closing early at 3:30 Friday 5/27 and remain closed Monday for Memorial Day (5/30). Orders placed after 2pm MT on Friday (5/27) will process and ship out on Tuesday (5/31).

Retired Product

This is a retired product. There is an updated version available: WIG-12772

Creative Commons images are CC BY-NC-SA 3.0

Description: The Logomatic v2 takes everything we learned with multiple logging projects over the years and boils it down to an easy to use device, that is now more adaptable than ever! Version 2 incorporates the LPC2148 with USB, battery charging, and microSD support. This allows us to use the SparkFun LPC2148 USB bootloader for even easier and faster modification of the firmware. No programmer required!

The Logomatic v2 uses a USB mass storage stack to appear under any operating system as a flash drive. Logs are created in FAT16 format on the micro-SD media and can be downloaded quickly over a USB connection by dragging and dropping the text files from the device. The microSD card can also be removed and inserted into a card reader to download the logs.

Board comes with a JST connector to be powered from our line-up of LiPo batteries or other power sources up to 7.5VDC. If you choose to use LiPo batteries, the Logomatic v2 has a built-in charger to charge batteries off USB.

The Logomatic v2 ships with basic serial text and analog logging. Users can easily start with this firmware but are encouraged to modify the firmware for their specific requirements. It’s a truly flexible logger.

As one of our most popular products, the Logomatic has a ton of uses, and makes for a wonderful gift! For other great gift ideas, check out our SparkFun Gift Guide.

Dimensions: 1.5x2.4"


  • LPC2148 ARM7
  • 512K user flash
  • 10 available GPIO pins
  • 2 Status LEDs
  • USB Link LED
  • External interrupt
  • micro-SD socket
  • Compatible with low-cost flash media (related below) up to 2GB
  • Built-in MCP73831 USB charger (300mA max)
  • Built-in USB mass storage device bootloader



Recommended Products

Customer Comments

  • I was able to get it running with slow data (e.g. one line of ASCII per second at 9600 baud). At higher data rates (hundreds of bytes per second at 38400) it records nothing, garbage, or intermittently. Ideas?

    I am running straight from an Arduino serial port. I’m as sure as I can be that the bits and parity are correct. I can see correct output with the Arduino serial port monitor on my computer. I am using the RXI0 and TXO0 on the programming port of the Logomatic; I could not find in the data sheet which UART is preferred to log (this or the TX01 RXI1 on the other side).


    sample lines logged (first line is OK), Sometimes it is complete garbage, sometimes like this. 0,0,0,0,0,0,0,0,0,267,0,-90.00,268,19 0,0,0,0,0,0,Oâ& &ó-105.0,0,0,0,0,0,0,0,0ˇ¶S&K8,-90.00,284,19 0,0,0,0,0,0,¸ˇräöbí≤∫j§¯0,0,0,0,0,0,0,0,0,276,0,-90.00,287,33 0,0,0,0,0,0,0Ï˛ &ó-105.00,0.00

    • I am having the same problem using a PIC. I can get it to work fine at 19200, and then when I step up to 38400 the data becomes garbage on the logomatic side. I of course changed the baud setting from ‘5’ (19200) to ‘6’ (38400). And when I read the data in directly from the PIC using a serial logger it comes through clean as you were saying with the Arduino serial port monitor. Did you ever figure out what the problem was?

  • I can log data and see the config file on my SD card. But when I try to upload new firmware, it doesn’t reprogram (and it removes the FW.SFE file from the card). I’ve formatted the card to FAT16 using Windows XP and another piece of software listed in a link on the bootloader tutorial. Anybody solved this issue? Thanks!

  • I picked up 2 units for a little experiment, but neither do anything, as in they appear to have no programming …:(
    I formatted a 2GB card, inserted it and powered it on, and the only LED that comes on is the charge LED.
    I am using the USB power only, with no battery. I first tried it only feeding 5V in via the connector pin, then I tried using the USB connector as the power. The unit never has the USB LED come on, and it never communicates to become an external drive on the computer.
    I am not currently set up to reprogram them….
    Thoughts or comments appreciated.

    • You need to connect BATT to USB to get power to the device from the USB connector.
      I wonder if SparkFun could change the switch in future versions from a simple on-off switch to a source-select switch - i.e. select between LiPo and USB power.

  • I must be missing something. It seems to run but when I open the txt file, it is blank. Something appears to be there but I can’t see it. What is the best way to look at the data?

    • Did you ever figure this out? I’m having the same problem…

      • Got it! I had to reformat the SD card again. (I formatted it with a macbook and then a virtual PC – neither worked. I had to switch to my ThinkPad and that did it.)

  • I can’t get my logomatic to run the initial startup. I formatted my SD card to FAT16, inserted it into the card slot, and supplied power using an external battery (i tried this using the white power connector and the “batt” pin). The “USB” light comes turns on, and after maybe 10 seconds, the “STAT1” and “STAT0” lights turn on and stay on. I do not see any lights “blink reassuringly and then go quiet” like the datasheet says it should, and it never creates the configuration file on the SD card. Can someone please tell me what I’m doing wrong?

    • never mind, my problem seemed to be that my SD card was too big–I got a 2GB card instead of 4 and now it works.

  • Can the logger write to a file while connected to a PC or is it possible to implement composite USB behavior, so logging data can be read directly while its connected to a host pc?

  • If you ever make a new version of the logomatic how about coming up with a way to break out the VBAT line so you can keep the RTC running. It would be real nice for a logger to have time stamps on the data files.

  • Still no support for SHDC cards?
    Micro-SD (non-HC) cards are getting pretty rare nowadays. Or is SparkFun just trying to sell more memory cards?

  • I would appreciate it if someone could point me to a user instruction/manual on the logomatic. It seems that one edits a text file to setup the data logging parameter - is a firmware install required ? …bootloader install ?

  • I bought this to connect it to connect it to a Redboard but I cant figure out how to hookup it up. Which pin needs to connect to which?

  • FYI, It appears that this device as it currently ships DOES NOT work with MicroSDHC cards, which is pretty much all that can be bought these days. You’ll need to salvage a MicroSD card from an old phone to get it running. A very generous chap (Kwan) has created an updated firmware which allows MicroSD HC cards to work. Can I suggest sparkfun update the shipped firmware on this device to handle HC cards?!?!?! If you do buy one of these then read through (this first..)[https://forum.sparkfun.com/viewtopic.php?t=16539]

    • We’ve got an update specifically for this in the works. Should be going live soon!

  • For anyone who is fiddling about trying to get their SD card reformatted to 2Gb or less on a windows system, it’s slightly harder than right click/ format / properties… Follow this tutorial exactly and you’ll be on your way.

  • Two questions: 1. Should this device work with Windows 8 2. Can I power it by connecting “USB” to “BATT”

    I’m getting the famous “USB Device not recognized” when I plug it in to the computer. Anybody have ideas on what I can try now?

  • I bought a Logomatic to log RS-232 engine data from the engine monitor in my aircraft. I didn’t have a good look at the datasheet, and upon review it appears that the OpenLog is a better fit for my project (I don’t need a battery, USB support, or ADC). If you’re looking to buy a Logomatic, send me an email and I’ll sell you mine (at a discount): doepner.ar[at]gmail.com.

  • Is there a way to use a debugger? JTAG?

  • Hello Sparkfun

    I have had a problem with corrupt data, when using channel 6 of the logomatic data logger.

    The problem present it self by corrupting the data of row1 in the data logged (in the txt file).

    At first i thought i had a problem with my input circuitry, but i have since verified the problem on a spare board i have, without any input circuit connected.

    I have been investigating the problem further, by connecting a pot meter to channel 6, which i can adjust from 0 - 3,3[V]dc. I have included a portion of the sampled data, so i can illustrate the error, which i have concluded, must be an software error, which only presents itself under certain conditions.

    Row 1 data is being corrupted by row 6 data, when the ADC counts are turned above 1000.

    The last digit in the previous row 6 sample, is being written into the next row 1 sample.

    378 33 36 38 25 36 31 1018

    • Sorry to hear you are having troubles with your board. Please contact techsupport@sparkfun.com and they should be able to help you in depth with this issue.

  • Can anyone tell me the mounting hole pattern?

  • For the record, it looks like the A/D channels read 10-bit values (0-1023) from 0 to 3.3V. Correct me if I’m wrong.

  • I am also having trouble with reading the data in the binary form. I currently have it hooked up to a Function Generator at 10Hz and a frequency of 100Hz on the configuration final. This should easily fulfill the Nyquist Criterion. However when I open the text document the data outputted is just the $$ delimiters with the occasional box or other strange character (like a foreign language that needs to be translated). Can anyone help me out?

  • Can I use this to log UART signals? If so, what do I need to do to start logging, and is there much coding involved in interpreting UART data? - Sorry I’m quite new to this.

  • Hi there, has anyone ever used the binary option and got some tips on how to interpret the data? I have never used binary data before and when I open the files in a text editor is obviously only shows gibberish. I am in desperate need of the higher sampling rates the binary format can achieve. Thanks for your help!

  • Ok.. this took me a while to figure out- hopefully my comments will save someone some time. I have Windows 7- in order to format the SD card to FAT16 I had to download a free utility called SDformatter. The problem is you have to have an SD card that is 2 GB or below. I had an 8 GB that I couldn’t partition. Once you do that.. it should be smooth sailing.. good luck!

  • My problem has been solved, thank you

  • Is it possible to use I2C instead of SPI?

  • I am thinking of buying this product.I am trying to log voltages for my project @20Hz but I am not sure how the output reads. Can it directly log voltages or is it in ASCII? An exemplary recorded data format will be really helpful.

  • Hey there, For anyone else out there trying to do low-frequency analogue data logging with the standard firmware, there is a trap with single-didgit frequency values in the LOGCON.TXT file. The firmware needs a minimum of two digits to process from the configuration file, so single-digit values of frequency cause the firmware to hang. To get around this you simply add a leading zero to the frequency value. Logging at 1 Hz does not work, but looging at 01 Hz does! Cheers.

  • I received a Logomatic V2 last week and finally got it hooked up to some 1-wire DS18S20 and I get nothing in the log other than hundreds of “$”. I decided to aquire an Arduino Uno R3 and hooked it up to the DS18S20 with instant results after I loaded the demo temperature file. I then (after seeing a youtube video) connected the tx from the arduino to the rx on the 6 port side of the logomatic and I can see all the temps logged. How do I get the RTC to work and do I need to use the RS232 shifter to connect the 1-wire components to the logomatic?

  • What is the power consumption of this device?

  • The RTC clock crystal is marked on the schematic(above) as 32Khz, the LPC214x user guide says to use a 32.768Khz crystal, so what is the actual value of the crystal used on the logomatic?

  • Has anybody tried to reconfigure th I/O this to use the “10 available GPIO pins” that are listed above?

  • Does anyone have the original Bootloader MAIN.HEX file that is set up to work with the logomatic(ports set correctly etc) , if so where can I download it from, or is there a better one? thanks

  • This is in an ARRL QEX magazine article, http://www.arrl.org/files/file/QEX_Next_Issue/May-Jun_2012/QEX_5_12_POST.pdf

    de W7AS

  • Hi there! I’m also VERY interested in using this nice device for logging raw binary gps data via UART. When I read the docs I assume that there’s no support for this kind of binary messages so far. Is there somebody who can confirm that? And “last but not least”: Is it possible to change the firmware for this? Edit: just (maybe) a little bit more special - the messy mix of ASCII (NMEA) and binary UBX messages from u-blox GPS/GNSS units. Any chance to write this (as coming from UART) directy to the file on SD card?

    • There is an alternate firmware that a user provided a few years ago which appears to support your request. http://code.google.com/p/logomatic-kwan/

  • In a blatant attempt to get readers to my blog, I direct your attention to here . The firmware is now more than halfway done, it actually works. Go to this blog entry, get the links to the new firmware there. Use the bootloader tutorial to find out how to get the USB bootloader onto your Logomatic.

    Sparkfun guys: You are welcome to examine this code, and if it meets your approval, use it on future production runs of the Logomatic.

  • Has anyone used this device for logging binary serial data? I have used this device: http://www.acumeninstruments.com/Products/SDR2-CF/index.shtml for logging raw binary gps data, and was hoping to use the logomatic to perform the same thing, is this possible?

  • Bonjour, I try to record gps messages, 4800 bauds.($GPZDA,…..) Input on RXI-0 In mode 0, that’s OK (STAT0 and STAT1 are blinking). Data are recorded on SD card. In mode 1, with trigger =$, nothing appends !!! STAT0 and STAT1 OFF permanently. Have you an explanation ? Thank’s. Alain.

  • This worked great until I fried something on it by connecting it to usb while an unpowered external supply was connected to Vcc. I’m left unsure how you’d actually run it from an external 3.3V supply if this is the result, so I guess I won’t replace it. Now it’s a $60 Lipo charger…

  • Hi all I have formatted two different microSD cards using windows XP, Windsows 7, Ubuntu, SDFormatter from sdcard.org, and a few other formatting tools, but both of the Logomatic V2 that I ordered do not do anything, no files are created on the microSD cards and no lights flash only steady lights. Have used both power over USB and a 7.4V battery. Any help would be very useful

  • I would love this little logger, if it either had better documentation and definition of what it will do. NOWHERE in the documentation of this SERIAL datalogger does it mention that you can’t connect it to a SERIAL port directly. Really? First off, why doesn’t it accept RS232 signals without using a PRT-00449? Second off, in the datasheet, when it talks about UART logging, does it not MENTION this. I just ordered a PRT-00449, and hopefully haven’t fried my UART in the process of trying to log from the serial port. I will update here if I have any success, so others don’t get burned.

  • Above it says “The Logomatic v2 uses a USB mass storage stack to appear under any operating system as a flash drive” Can anybody confirm success on an Android device…? Thanks

  • Hello: Ive a doubt about this logger. With the main firmware can I log a serial signal and four analog signals at the same time? Thanks Jess

  • SINGLE CHARACTER TYPO BUG IN V2 CODE: Fix increases the V2 logging rate by 7.5x.

    Details: http://forum.sparkfun.com/viewtopic.php?f=14&t=31224&p=138916#p138913

    The bug is described at the end of the above SFE forum post, with the test in the following post in the thread.

    Anyone know the procedure for submitting a diff or patch or getting a git pull?

  • V2 Oscillator Questions:

    1. Which of Q1 or Q2 is more stable with temperature?

    2. Which of Q1 or Q2 is more accurate (better calibrated at time of assembly, more likely to be closer to nominal spec value)?


  • I have a 4GB Class 4 Kingston uSD card. Will it work in the V2 if I force-format it for FAT16 (2GB) and ignore the rest of the space?

    If so, any recommendations for how to do this under Linux? (I can also get access to a Windows machine if needed.) I’ve tried the obvious ways, but the original FAT32 filesystem stubbornly refuses to go away…



    • Got the forced format to work: The card shows only a single 2GB FAT16 partition. But when put in the V2 and powered up on battery, both the red and green status LEDs came on steady.

      Recommendation: Include a small known-good uSD card with the V2 (your margin should be OK for it), or at least keep one in stock. Or at the very least provide links to known-good devices.

      Having a new SparkFun device I can’t yet use is a bummer.

      The manual doesn’t even discuss this device limitation. Even a single sentence would have helped.


      • A good card to use is the very inexpensive Patriot 2GB model PSF2GMCSD, available for $1-$3 online (+ shipping), or $4-$6 in stores (Best Buy, WalMart & Fry’s have done selective internet price matching, but only with very reputable sites such as Amazon).

        For speed, it meets or beats cards I’ve tried from SanDisk, Kingston, and RiData. For power consumption, it meets or beats Kingston and RiData (I get up to 15% longer V2 battery life with it). YMMV: I tried only one card of each brand. RiData and Kingston, in particular, can have significant performance swings between lots.

        This card comes formatted in FAT32, so you will need to reformat it prior to use.

        If your uSD card has been used before, be sure to avoid doing a ‘quick’ format, as this will merely deallocate previously-used sectors, not erase them, making the run-time performance truly suck since those sectors will need to be erased prior to being re-written.

        If your uSD card is of an older generation (lacking deep ECC support and/or automatic bad-block detection), or has been completely filled hundreds of times, be sure to do a bad block scan on it.

  • Can I attach two of Li Pol batteries ( 850 mAh or 1000 mAh ) in parallel to this charging circuit. Because I need more Amp hours for my project. http://www.sparkfun.com/products/341

    • Yes. LiPol batteries can be connected in parallel. This is commonly done in the hobby industry for electric flight.

      The charging circuit uses voltage to determine charge state so your penalty will of course be longer charge times because the charge current is limited by the charger chip.

      Just be sure that your batteries are in similar charge state when you make the connection AND they should be the SAME capacity so they get discharged equally quickly. Connecting a full battery in parallel with a drained one, may cause excess current flow between them as the voltage equalizes between them.

  • We bought some logomatic some few weeks ago, and we are trying to use them to log some data from our sensors. Unfortunately, we are meeting some problems to log data over a long period of time (more than 9 hours). Our sensors are sending 3 bytes to the logomatic v2 card every 312.5 µs at 115200 bauds. We also tried the 57600 baud rate to send periodically the 3 bytes to the logomatic. When the system is working after a long period of time (eg. 9 hours), the logger starts missing to log pages of 512 bytes and we don’t understand why because it was working well from the start till the 9th hour. Whatever the baudrate is, we have the same behavior (missing of 512 bytes pages). We did our tests on a lab power supply, to avoid the discharge problems caused by the battery.

    Could you help us understanding why we meet this logging problem with the logomatic, or do you have an idea where in the firmware some modifications could be done to correct this bug ?

    Thanks for your help

    • Problems like this are very hard to debug for obvious reasons, but thanks to your earlier messages to tech support we’re looking into it. One thought that SD cards tend to have slower response times as they fill up. You might try a faster-class card and see if the same thing happens. There may also be a subtle bug in the SD driver code (not written by us) which causes problems when the filesystem reaches a certain size. We’ll do our best to help with this, but I can’t promise a quick fix.

  • I notice a delay in the logging start times that seems to depend on the number of files or memory used. For instance, the logger starts logging around 0.75s after getting power for the first few log files, but as the number of files on the disk increases, the delay increases up to 15s for the 32nd log file. I have a calibration routine in the first few seconds after boot for my device, but all the data corresponding to this is lost. Is anybody else seeing this type of thing?

  • Hello,

    I am working with an IMU from Xsens. The kit comes with an RS232 to USB cable. Is this datalogger suitable enough for recording data from our AHRS? Any suggestions or alternative options would be highly appreciated.

  • i have data logger and can’t create a text file.
    when i format the SD card it say FAT32 instead of FAT16 as the data sheet says.
    can this be a difference. and what is the solution.

  • I have the text files on the drive, but no data in the Logo1.txt file. I’m trying to record serial text with the default settings. Stat0 and Stat1 aren’t lighting up during data capture at all as far as I can see.
    Does XP FAT format=FAT16? if not, can you recommend a formatting route?
    Do I need more than RXI0, TXO0 and GND wired to the serial plug?

  • Anybody know how to re-install the bootloader code into the logomatic?
    – Henry Heetderks

  • Logomatic v2 successfully writes files to 2G micro-SD but fails to “mount” on PC when plugged into PC USB and restarted. Using 3.7 LiPo battery for power, both windows XP and windows 7 do nothing when hooked up via USB. I’ve tried two different kinds of micro-SDs; both formatted FAT16; both successfully received the config file and blank data files; both were unseen by windows via USB. Anybody have any ideas? I’m quite stuck on this one.

  • I just created some useful FW mods to this cool little piece of hardware!
    I modded the firmware for mode0 to “autosave” every x seconds. I have it set to 10 seconds. I did this because I am using it for an application that frequently power cycles but I don’t have the ability to press the stop button.
    Also I modded it to append new data to a single file rather than generating a new file every time you power cycle it. Basically the USART I am monitoring over several days or weeks generates CSV data and gets power cycled several times a day. I wanted this to all be stored in one giant .csv file so I could quickly open this in excel.
    I’m not sure of a good place to upload this so if you are interested in my raw code or the compiled file (which you can easily use to update your own unit) just shoot me an email. My name is ian. My email is my name @orbotix.com

  • Note, there’s a bug in the documentation.
    The PDF documentation says
    Safety On = Y
    but the initial config file the device writes out says
    Saftey On = Y
    Note how “Safety” is misspelled here. If you spell it correctly, per the documentation, it won’t work right with respect to this setting.

  • how to i reprogram this product, what do i need to connect

    • You change the configuration file on the sd card in order to change the mode of operation of the board. You can do this over the USB connection or remove the sd card and write to it using a card reader.

  • can i use this with a arduino? can i get data of it while its running?

  • NOTE: This device DOES NOT WORK FOR ME! Be careful! It’s poorly documented, too.
    I can’t get this thing to work at all.
    I put in a 2 GB Micro SD. The LEDs blink when I power it on, but no LOGO/LOGCON files are written to the card.
    I’m pretty sure the card is formatted properly to FAT16; I tried it in XP and in Linux to format it. Also, I can read/write files to the card when I have it connected to a computer via a USB cable.

    • It’s poorly documented, too.
      That’s kind of silly to say. The schematic, board layout, and all the source code are provided. Every bit and byte, every wire and part is documented.
      My guess is that your SD card isn’t formated correctly. I had a card that I thought was good. It wasn’t, even though I could still read and write to the card through the logger as a mass storage device. I wouldn’t trust the windows /FS:FAT option if it doesn’t say “16” in the command. Your partition has to be 2GB or less. Maybe your battery supply isn’t sufficient so the board can’t operate correctly when you unplug the USB. Maybe you have a bad card or a bad board. You could also trying hooking up to the serial output to see what the debug messages say.

  • can i use this with a arduino?
    can i get data of it while its running?

  • a few questions:
    1) can i breadboard this (with headers attached)
    2) if i can, can i then attach this to an arduino
    3) once i have connected to the arduino is it possible if i can connect it to an arduino to ask for records back or do i need extra hardware.

  • SparkFun is currently sold out of their Micro SD Cards and I am looking for one that will work with this logger.
    What Interface standard should I be looking for?

  • Will the charger only charge single LiPo 3.7V cells or can it also charge 2 cells in series (7.4V)?

  • As others have mentioned, you have to format the card to FAT16. Windows 7 won’t do it, but XP will. Just select FAT and Default file size under the format menu.

    • I think you can format to Fat16 using the command line on windows 7 with the /FS:FAT option.
      I used a utility called mkdosfs.exe that was a Linux utility ported to windows.
      However, I can’t get my datalogger to work at all, so maybe I’m not formatting the card right!

  • Can this device send data from sd card on board thru tx output to another device.

    • Yep. RTFM.

      • I was reading the manual, but I can`t find anything that help us to do this. So, Is possible to send data from sd card on board thru tx output to another device? If this is possible? How can we do this? How do we have configure the LOGCON.TXT to do this?

  • Does this already have the bootloader installed?

  • In mode 1, what happens if the SD card fills up after an extended duration. Will prior data be overwritten or will it just stop logging?

  • Did you have to do any special think to be able to use FAT16? isn’t there some kind of law problems. I’m trying to write a code from zero to use FAT in my project, but I have found that you need a license from microsoft to use it, is that right?

  • Does anyone know which 3.3V regulator is used on this board? Schematic just lists 3.3V with no part number.

  • Where can I find its power consumption range?

  • I just want to know, What is the maximum and minimum voltage that I can to use on ADC inputs?
    I don’t want burn inputs…

  • string.h file is missing when i downloaded the code from (Main firmware on github) can any one help me OR where can i get working code for the same…

  • what are ADC Ports ?
    Analog to Digital Converter ?

  • I uploaded a version of the Logomatic to Fritzing on 2011/2/14 (fritzing.org/parts/ - go to “parts sharing entry” - you can scroll down to the date, or search for “Logomatic”. It’s based on the “other” v2, so I hope that the footprint and pinouts have not changed. They look the same as in the pictures here.

  • What transfer rates rates can this board get up to when reading from the mass storage device?

  • The datasheet (v21) still doesn’t mention which UART you are supposed to use for serial logging, but by looking at the source code you can see that it is UART0

  • I think there is a bug in the firmware that doesn’t let you use 1-9 for the logging frequency, these values just give you one sample every couple of minutes , but 01 to 09 are ok.

  • Soooooooo shouldn’t this be the V3?
    “Logomatic v3 Serial SD Datalogger”

  • Nice. I’m diggin' the 10-10-10 on this batch.

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