I am currently planning a long-term data logger based on the adafruit data logger shield with SD and RTC functionality.
This data logger should record one byte every second in a file named yymmdd.log (i.e. a new file every day) and ensure that every byte of that file is populated at the place corresponding to the current time.
That means every file is 86400 bytes long at the end of the day. That would also mean either to wait to start exactly at 00:00:00 or, better to prepare a file on the fly populated with enough zeroes to start recording at the right place during the day.
Has someone already done something similar?