Allows building within the Arduino Source tree, and within the Arduino
IDE tree, as well as using CrossPack on Mac.
Adds README.TXT to track arduino-specific changes (and documents the
new build options.)
This addresses Arduino issue:
http://code.google.com/p/arduino/issues/detail?id=487
And optiboot issue
http://code.google.com/p/optiboot/issues/detail?id=1
(which can be thought of as a subset of the Arduno issue.)
Note that the binaries produced after these Makefile changes (using any
of the compile environments) are identical to those produced by the
crosspack-20100115 environment on a Mac.
Because UBBR is only 12 bits, we were overflowing it at 300 baud because of the use of the U2X bit. Now we turn off U2X if it would yield a UBBR value that would overflow.
Note that this breaks 300 baud communication with the computer on the Uno and Mega 2560 because the 8U2 USB-serial firmware has this same bug (and previously they cancelled each other out). Since, however, it seems more likely that people will need to use 300 baud to communicate with other (legacy) hardware than with the computer, I'm making this change. Issue for 8U2 firmware bug: http://code.google.com/p/arduino/issues/detail?id=542http://code.google.com/p/arduino/issues/detail?id=522
Because UBBR is only 12 bits, we were overflowing it at 300 baud because of the use of the U2X bit. Now we turn off U2X if it would yield a UBBR value that would overflow.
Note that this breaks 300 baud communication with the computer on the Uno and Mega 2560 because the 8U2 USB-serial firmware has this same bug (and previously they cancelled each other out). Since, however, it seems more likely that people will need to use 300 baud to communicate with other (legacy) hardware than with the computer, I'm making this change. Issue for 8U2 firmware bug: http://code.google.com/p/arduino/issues/detail?id=542http://code.google.com/p/arduino/issues/detail?id=522
This makes explicit the String constructors that take numeric types and chars and removes the versions of concat() and operator=() and operator+() that accept numberic types.
It also replaces the operator bool() with a operator that converts to a function pointer. This allows for uses like "if (s)" but not "s + 123". See: http://www.artima.com/cppsource/safebool.html. This allowed removing the disambiguating operator+() functions and relying solely on StringSumHelper and anonymous temporaries once again.
Also, now treating unsigned char's like int when constructing Strings from them, i.e. String(byte(65)) is now "65" not "A". This is consistent with the new behavior of Serial.print(byte).
