Serial.parseFloat() returns the first valid floating point number from the Serial buffer. parseFloat() is terminated by the first character that is not a floating point number. The function terminates if it times out (see setTimeout()).
Serial.parseFloat(lookahead, ignore)

lookahead: the mode used to look ahead in the stream for a floating point number. Allowed data types: LookaheadMode.
Allowed lookahead values:
  • SKIP_ALL: all characters other than a minus sign, decimal point, or digits are ignored when scanning the stream for a floating point number. This is the default mode.
  • SKIP_NONE: Nothing is skipped, and the stream is not touched unless the first waiting character is valid.
  • SKIP_WHITESPACE: Only tabs, spaces, line feeds, and carriage returns are skipped.

ignore: used to skip the indicated char in the search. Used for example to skip thousands divider. Allowed data types: char.