Serial.parseFloat() returns the first valid floating point number from the Serial buffer. Characters that are not digits (or the minus sign) are skipped.
parseFloat() is terminated by the first character that is not a floating point number. The function terminates if it times out (see Serial.setTimeout()).
Serial.parseFloat() inherits from the Stream utility class.
Serial: serial port object. See the list of available serial ports for each board on the Serial main page.