So I'm trying to create a new file that has underscores in its name. However, when I try this, no file is created.
This works
String fileName = "NMEA.txt";
mySensorData = SD.open(fileName.c_str(), FILE_WRITE);
This does not work
String fileName = "NMEA__23_33_3__16_7_29.txt";
mySensorData = SD.open(fileName.c_str(), FILE_WRITE);
Does anyone know why?