Where to Find the Logger ID for Mayfly Data Logger

I’m not sure what the Mayfly Data Logger Pro is.  Do you mean the program (or sketch) used to configure the board?  If you’re using one of the provided sketches we publish on Github, there’s a couple lines in each sketch that looks like this:

The Logger ID is just an alphanumeric designator that you can use to name your station to help with record-keeping and organization, because the logger ID becomes the prefix for the data file that is written to the Mayfly’s microSD card.   All Mayfly data card files are named using the Logger ID and the date the file was started.  So a Mayfly with the logger ID of “BLUE” would have a file named “BLUE_2023-07-20” if the logger was started today.

If you look through the EnviroDIY Monitoring Station Manual, you’ll see examples and further descriptions of the file operations of the Mayfly.  The manual was originally written for our partners in the DRWI monitoring program, and those stations were all built and programmed by me, and we used an internally-generated logger ID system starting with the letters SL.  Other users are free to choose any name or number they want.

In general, it’s good to put the stream name or some other helpful info in your logger ID (while still keeping it short, and using underscores instead of spaces) because it will make the names of your resulting microSD card datafiles more descriptive.  For example, i might call one “Upstream_JonesCreek”, that way all my data files will begin with that string, because there might be a “Downstream_JonesCreek” station too.  A new data file is created anytime the Mayfly station is rebooted, so if both stations are out collecting data and both get visited today and have their data cards swapped with new blank cards, they will both start recording to data files with today’s date in the filename.  It’s the Logger ID that will make the filenames unique so that when you later copy both of those data files to your PC, they’ll be uniquely named and there won’t be any confusion about where they came from.

Another note, the Logger ID as written in the Arduino sketch of the Mayfly board is not the same as the Site ID of a station on Monitor My Watershed.  That’s a different type of naming convention that is independent of the Mayfly programming.  The string entered for Mayfly Logger ID in your sketch is only used for generating the microSD card filename on the logger.