I've been working with sir morris' SD from the ground up for several months. The system works OK for me. I've been using it to count electronic pulses per second, then store the count/sec on an SD card.
I have used the system to count/store pulses from the speed sensor on my Harley Sportster. I can remove the SD card from the arduino ckt. bodily transport the card to my laptop where I download the data via USB into notepad (or wordpad), from whence I can enter the data to my spreadsheat for scientific analysis (HA-HA).
I could also use the circuitry to count pulses from the ignition system, or whatever pulsating electronics that I desire to take a look at.
Problem, though. New data entered on the card replaces previous data, so its hard to keep track of which is old, which is new. New data always starts at the beginning of pre-entered data, and overwrites the old. Therefore, one needs to modify the program, adding something, that id's old from new, but data still gets jammed together.
I use the atmega's EEPROM to store a number, which is increased each time I shut the ckt off then restart it. That number id's each use, but older data is still overwritten and can be lost. However, one needs not shut the ckt off intentionally, as data can be entered to the card for a long, long, I don't know how long, time. Of course, there are times when the ckt. shuts off unintentionally.
Recenty, I added an accelerometer to the system. It does a real good job of recording every bump on the road. So, OFF with the accelerometer. :
PO'T