Hardware Reference
In-Depth Information
static const uint8_t A4 = 22;
static const uint8_t A5 = 23;
static const uint8_t A6 = 24; // D4
static const uint8_t A7 = 25; // D6
static const uint8_t A8 = 26; // D8
static const uint8_t A9 = 27; // D9
static const uint8_t A10 = 28; // D10
static const uint8_t A11 = 29; // D12
The rest of the file configures the ports and other features to support these constants.
Uploader Options Renamed to Programmers
There are several programmers supported in the list. The supported programmers are
•
AVR ISP
•
AVRISP mkII
•
USBtinyISP
•
USBasp
•
Parallel programmer
•
Arduino as ISP
These options make it easier to program devices that don't have serial or USB serial ports. The smaller chips, like
the ATtiny 4313, 2313, 85, and 45, can only be programmed via one of these programmers. These programmers can
also be used to put new bootloaders onto Arduino boards. Additionally, they set the chip configuration and speed.
New Bootloaders
A bootloader is the software on the Arduino board that loads the sketch into memory. The sketch is compiled into
a HEX file. The bootloader receives the HEX file from a programmer called Avrdude, and then loads it as the active
program on the device. Several new bootloaders come with Arduino 1.0.4:
•
Optiboot
: The bootloader for the Arduino Uno rv3.
•
Diskloader
: The bootloader for the Leonardo and 32u4-based boards.
•
Stk500v2
: The bootloader for the Arduino Mega 2560.
USB Firmware for 16u2
The firmware is for the USB support and VID information for official Arduino boards. The USB firmware for 16u2
also contains the LUFA library, which Arduino licensed for official USB support. This firmware is burnable into the
Atmega16u2, the Atmega8u2 for the Arduino Uno, and the Arduino Mega 2560. These are now updated for all the
revision 3 boards. Revision 3 also removes the FTDI USB support and replaces it with the Atmega16u2.
You need to use the DFU programmer to program this firmware into those chips. The DFU programmer is
Additionally, a modification to board needs to be enabled to allow the programmer to communicate with the
chip.
