Connecting arduino to logomatic v2 datalogger

Hi I was wondering how I can connect my arduino duemilanove to the sparkfun logomatic v2 datalogger. I formatted my 8gig sd card with fat16, put it into the logomatic and powered 5v and ground from my arduino to the white battery + - port, i then put it on and the stat1 and stat0 flashed for a second and usb remained on (usb cable not connected). I then put the sd card back in my sd reader on computer and it created the LOGCON.txt file but with nothing in it. I copied and pasted the configurations from the datasheet, saved it, then connected the tx00 and the rx00 to the arduion rx and tx and loaded a simple program on the arduino to print the analog pin 2 read every second. Nothing would print to the SD card, neither with serial monitor on or off. After a few seconds the stat0 would stay solid and if i pressed the stop button nothing would happen. Am I connecting it right? Anyone know why the config file was created empty? Hope someone can help.

I'm having a similarly frustrating time with this datalogger though I am getting further than you I think. I did get a config file written to the card but cannot get anything over the serial port logged.

The logger is a 3.3v component and I'm not at all clear whether it will read the 5v TTL levels from the Arduino (a Pro Mini 328 16Mhz 5v unit in this case). I may even have fried the logger serial connection trying.

I did get it to log from a floating analog input though the first log file name is corrupt. Makes me wonder if this is actually v0.9 of the firmware!

I have asked on the Sparkfun site but as someone there pointed out, there isn't a big community of user there.

It's a shame because it ought to be an ideal way to log accelerometer readings etc over a long period.


I have these two on my desk right now!

Arduino connected to laptop via USB. Logomatic V2 connected to Arduino via 3.3V, Gnd and only a single serial data wire from Logomatic RX to Arduino TX (pin 1). These are all on the 6 pin header side of the board. No connections to the other side of the Logomatic board.

A simple Serial.println("hello world"); line in the program loop gets logged just fine.

Be sure to use MODE 0 to have the board simply log everything it sees! And be sure to set the baud rate to match whatever you are actually using! The other parameters are unused in this mode and their values don't matter.

MODE = 0 ==> log everything coming via serial port
Baud = 7 ==> 56KB

Ensure everything plugged in, powered on, and no card inserted. Ensure the power switch on the logger is ON. The red and green STAT0 and STAT1 LEDs should both bit lit and steady, if not press reset on the Logomatic. Insert the card. The logger STAT lights will blink rapidly to show a new file was created and it is now ready to log. The STAT lights will blink once enough data has been written to the buffers to cause them to write to the card. When you're done press the STOP button. This will clear the buffers of anything not yet written to the card. When this is complete and the STAT lights are steady you can remove the card.

Remember that the two led's (Stat0 & Stat1) will blink ONLY when the board dumps the 512 byte buffer to disk.

I hope that helps!!


Thanks. Is your Arduino a 5v part or a 3.3v unit? That was my concern?


I got it working, forgot how as it was a few days ago, I think I just played around with different variations, card in, card out, etc. Great product.

Can anyone guide me in the right direction for retrieving the file contents of the SD card to be posted back to the arduino via Serial? So if you send the command “Read5” through serial it will send back something like =

File contents logfile5.txt =
this is a test
this is a test

Is this something that would be hard to do? I would have to modify the bootloader right?