Requirements: Arduino UNO, micro SD module.
Use SD_05.ino for datalogger generating several files managed by reset button. Use SD_03 for a simple datalog where only gives DATALOG.txt file and csv data struture. Use SD_04 for code evolution to multiple files, but isn't working after 10 files.
We're developing a Datalogger with you don't need understand code structure for n variables. Pay attention when SD_10.ino is released!