Some additional logging info when I ran it over night again, still on version 23. When I look at the files, I think of the TV series the X-Files :)
7 new files were created.
The first 6 files have windows7 file properties of both Created: and Modified: December 31, 2097. The first 4 of the 6 have the wrong firmware (FW: 1462564395). The SD card had 35 of my previous files, so maybe these were old files, but I do not remember 2097 dates. The headers info is all wrong and the timestamp in each of the files start out at approx 4 seconds and increment by 1 sec (I verified afterwards the logging in the app was set to 10sec). The measured data looks like it may or may not be old data. The last 2 of the 6 files have the correct FW version, with a header, but no measured data.
The 7th file (LOG042.CSV) has windows7 file properties of Created: December 31, 2097, 11:00pm Modified: June 18, 2016, 2:07am. There are multiple headers with no measurement data. The firmware version is correct FW: 1466039460.
So, is it possible, the new firmware modified the old files if they existed? All the file LOG numbers are in sequential order, none missing.
Independent of the above weirdness, the LED blinking still indicated it was writing to the SD card this morning. Clearly, it wasn’t. So that is no longer a reliable indicator for me.